THEORETICAL FOUNDATIONS OF IT Prof. Witold Chmielarz, PhD Faculty of Management, University of Warsaw.

THEORETICAL FOUNDATIONS OF IT Prof. Witold Chmielarz, PhD Faculty of Management, University of Warsaw

Objectives of the course  Main objective: presentation of basic applications of information technology in contemporary organizations  Auxiliary objective: presentation of the forecasts concerning the role of IT in the near future

Contents of the lecture  Basic concepts of IT  Business information systems  Hardware  Data representation and algorithmisation  Computer software  Technologies of gathering and presenting data  Technologies of storing and processing data

Literature  Turban E., R. Rainer, R. Potter: Introduction to Information Technology, John Wiley &Sons, NY, 2004  Turban E., R. Rainer, R. Potter: Introduction to Information Systems, John Wiley &Sons, NY, 2008  Korczak J., Dyczkowski M. (eds.), Informatyka ekonomiczna część I. Propedeutyka informatyki, technologie informacyjne (Economic IT part I, Introduction to IT, Information Technology) Publishing House of Akademia Ekonomiczna we Wrocławiu, 2008

“Abundance of knowledge does not teach men to be wise.” ― Heraclitus

Business Informatics  clarifies basic principles of methodology and pragmatics of its use in various economic objects, broadly understood resources of computer technology  area which unites the general objectives, methods and resources used for multi-level processing of various economic data in order to meet information needs of various economic entities.

Information Technology Typology of IT concepts IT objectivesIT methods General Practical Internal External IT resources Hardware Software

INFORMATION FLOW SYSTEM  Reflects all material processes (supply of materials, raw materials, work-in-progress, production stage, storage of finished products, delivery to the recipient, etc.) and financial processes (service purchase, sale, financial accounting, financial analysis) taking place in the organization

SPHERES OF INFORMATION FLOW SYSTEM  Codified (the systems of norms, principles, rules, regulations, standards, etc.)  Non-codifed (informal system of addiction, blackmail, deceit, gossip, bribe, "access", etc.)

SPHERES IN THE INFORMATION FLOW SYSTEM  In the information flow system, there are certain decision points, where, based on specific algorithms, the transformation of input to output data occurs.  The algorithm appears here as a formal or non-formal description of the steps leading to this transformation. At a higher level of abstraction, the compilation of all algorithms illustrating the sequence of decision-making process which reflects the information flow in the information circulation system is also called an algorithm.  Algorithms show the system of multi-faceted, mutual relations among the decision- making points, the network of relations illustrates the structure of the information flows in the organization (the structure of an information system).  An IT system which is created in the organization should be a superstructure? over the existing information system. From this point of view, the IT system is the part of the information system within the organization, which is designed to support management with the aid of computer hardware and telecommunications equipment as well as with the help of the people with the right skills, trained to use it.

THE PLACE OF IT SYSTEM IN THE ORGANIZATION  ORGANIZATION  ENVIRONMENT  Non-formalized sphere  Formalized sphere  IT system  Information system ??

BASIC PROBLEMS  What happens if an information system will degenerate?  Is it possible to computerize the stage of degeneration of IT system ?  Is it possible to computerize only the codified sphere?  Is it ethical to computerize the uncodified sphere?  Is it possible to enforce the creation of an information system based on the IT system ?

DERIVATIVE PROBLEMS  Are the sources of all necessary information codified?  Is the information flow adapted to the needs?  Are (mental) algorithms and decision problems well defined?  Do better algorithms exist?  Do formal algorithms of solving decision-making problems exist?  Are decision points arranged in the codified sphere?

SECTIONS OF ANALYSIS  Required information – available information - decision-makers are supplied with excessive information i.e. information which they cannot process before making a decision, information in a different section than needed in order to make a decision, information which is not initially prepared, information which is unnecessary, confusing or incorrect,  Possible algorithms – used algorithms – it may appear that there exist faster algorithms of processing decision-making tasks than those being used, if - from the organizational point of view it may turn out that we may apply only some of options from the whole range of possible available decision-making algorithms used for proper functioning,  Statistics – organization dynamism – the problem is not simply to identify the present situation (separating objects, flows and relations), but also to identify a sequence of the situation at a certain time and relations between objects taking place in the process of dynamic development of the organization,  Integration – disintegration of information flows in the organization – each innovation in the organization is accompanied by the risk of bringing the organization to unintentional chaos. Hence, among others, the reason for the popularity of the „comprehensive”, „integrated” and „global” systems, etc.

IT SYSTEM FEATURES  relevance of the content and scope of information considering the needs of senior management (including the codification of uncodified realm on the path to broadly perceived restructuring or reengineering)  adjusting the speed, frequency (dynamics) and the volume of information to the decision-making cycles  adjusting the information flow channels of IT system to the information structure of the information system  communicativeness of the forms of information presentation, be it contrary to the previous patterns of information system  timeliness of information – developing specific mechanisms which would ensure providing information at the right time  minimizing the cost of obtaining and storing information

INFORMATION CHARACTERISTICS  availability - providing an appropriate amount of information at the right time  comparability - relating to information selection and its delivery time  credibility - identifying the sources, suppliers, codes, translators, etc.  processability - no tolerance for approximate data  frequency – inflow of the appropriate quantum of information per unit of time

FUNCTIONS OF INFORMATION SYSTEM  recognition: registration, identification and distribution of information  model-algorithmic: diagnosis, prognosis, simulation, generating standards of the organization operations  regulatory: aggregation, disaggregation, confrontation, information control

TRANSFORMATION OF THE INFORMATION SYSTEM INTO IT SYSTEM Identification of repetitive, mass, routine information processing activities Identification of repetitive, mass, routine information processing activities Identification of decision-making problems with greatest information complexity and algorithmic significance Identification of decision-making problems with greatest information complexity and algorithmic significance

 What is at stake - an information system transformation in IT system - is the actual inclusion of the IT system in significant management problems of the organization and determination of its place in the management system, as contrasted with automatic copying of conventional processing operations.  The success of this project acts against superficiality, pretending, ossification and obsolescence of information used in the decision-making process.  CONCLUSION:

Relations among data, information and knowledge DATA („bare” facts recorded on specific medium) KNOWLEDGE INFORMATION Data processing and analysis Drawing conclusions and learning

Information gap  The main task of information in each economic object is to reduce the uncertainty in the decision-making process  Information gap - the difference between the collection of required information and the collection of information at the decision-maker’s disposal

Information and management functions I  Planning, i.e. setting objectives which a particular economic entity intends to achieve in a given time and setting tasks, the implementation of which would ensure meeting these objectives. Identifying objectives and tasks covers various areas of economic activity of the business entity and applies to periods of varying length.  Organizing, i.e. pooling and allocating resources. Resources are indispensable in order to achieve goals and objectives. They include human resources, material, financial and informational resources. The first three of these types of resources are market-based, and information resources are the only internal resource of a particular economic object, i.e. thus determined in terms of the scope and quality. These resources must be acquired and properly distributed (allocation) inside the business organization.  Motivating - the creation of conditions for efficient and effective work of people employed in the business entity, taking into account the purposes of the tasks to be implemented and available resources. Personnel and wage policy implement the concept within the organization.

Information and management functions II  Controlling, or comparing the results achieved against objectives and targets, plans, standards, etc., to see how a particular business entity functions (based on feedback and analyses).  Coordinating, which consists in ensuring a harmonized interaction of the presented functions. In many practical situations it is necessary to simultaneously engage several activities related to multiple functions.  Deciding consisting in making non-random selection of action, from the available set of acceptable and rational actions. It is the “cross-sectional” function of i.e. a common feature of all the previously mentioned functions.

Information according to the criterion of occurence  macro-economic information, which we deal with, when the object the entire national economy or the economy of several countries, can be divided into two types:  Macro-economic information which we deal with, when the object the entire national economy or the economy of several countries, can be divided into two types:  universal (common) - intended for a wide audience, regarded as an element of the so-called information service, where information is collected, stored, processed and transferred by specialized information centers  specialized (industry) - used for macroeconomic and long-term planning, surveillance, control, etc.; This information appears in particular industrial sectors; It is laying the foundation for the development of industry-specific business plans and exercising control and supervision over the company’s operations

Information according to the criterion of occurence - cont.  micro-economic information, microeconomic information that operates within a given company and relates to specific products made by a given manufacturer and the service provided by a particular business entity can be divided into two groups: :  external - it includes data from outside the company, so their primary carriers are documents issued outside of the parent company,  internal - created in individual enterprise units, where this information plays a decisive role in the system of economic information within the company.

Information according to the criterion of time  retrospective information (describing the past) - maps the past values of the object characteristics, events and processes in relation to the time when the information is applied by the user (e.g. costs of production last year), this is statistical information (which are quantitative characteristics of a given set of units, non-identical in terms of value of considered features), and reporting and registration information (required for ongoing monitoring and economic analysis)  current information (describing the present) - this is the information that at the time of use covers the information needs of the user and there is no other information concerning the same features of an object, event, or process, in other words, there is no information which would be "more relevant" e.g. the current net price of the product X

Information according to the criterion of time - cont.  prospective information (describing the future), concerns the future values of object characteristics, events and processes, for example, we distinguish here:  prognostic information (relating to future states of reality which we cannot exert significant influence on, e.g. the inflation forecast)  planning information (for example, expressing an act of will, e.g. planning production costs for the next year).

Information according to the criterion of explaining phenomena Taking into consideration the manner (goal) of explaining phenomena and processes occurring in the business activity of small economic entities we distinguish the following types of information:  factual - describing events, processes or objects identified within the company or in its environment  normative - describing norms functioning within the company or in its environment (regulations, codes, rules and procedures)  structural - describing and characterizing the structure (relationships between objects) of phenomena, processes and objects  taxonomic - describing ways to organize, categorize, distinguish or evaluate  procedural - included in operating manuals, economic models, mathematical formulas and statistical data  semantic – including definitions or interpretations of terms used in business and management

Information according to the criterion of influence on decision-making processes  monitoring information – relating to the current situation of an economic object in order to check whether economic processes take place in accordance with adopted assumptions  progress information – indicating the chances of the development of an economic object  warning information – signalling a threat or a possibility of a threat in the functioning of a particular economic object  planning information – referring to the possible development of an economic object  opinion information – informing about the immediate and general environment of an economic object

Information features  The information is processed to obtain new information  Information can be easily transmitted by means of information and communication technologies  A need to update information is its specific feature  Another feature of information is its diversity, resulting from the differences between considered objects, their diversity, various information sources and their subjective consideration by users  Another feature of information is its non-linearity. Even a small amount of information may cause serious consequences, and the vast amount of information may be useless  Information is treated as one of the basic economic categories

The features relating to the quality of information  Uniqueness - the information is factual and subject-based i.e. it concerns a specific subject and we know who its author is  Relevance - we receive only the information which is needed in a particular situation. This feature eliminates the excess of information  Completeness - it is the information necessary and appropriate for a particular economic situation. This feature eliminates the insufficiency of information  Credibility (reliability) - refers to the correct way of creating information or obtaining it from sources which carry it out by means of objective methods. The credibility of information is not an absolute value, hence we distinguish between information which is reliable (assuming certain criteria evaluations), probable (in the sense of probability theory) and projected (based on intuition)  Timeliness - all the necessary information is received on time. It is important to determine the expected extent of, or the established news period, and thus the degree of "validity" of information. This feature eliminates situations where information would be received too late or too early.  The brevity (conciseness) - all the necessary information is obtained in an intelligible and immediately applicable form  Usability - information is necessary and useful for decision-making  Compatibility - with the law or with national or international standards

The functions of information  informative  decision-making  controlling

Informative function  informative function consists in creating knowledge resources  it is the most frequently perceived feature of information, especially in the context of exploring a new reality, learning, making choices, etc.  it is being realized by providing all objects with the information necessary for these objects to possess relevant knowledge, and as a consequence, resources necessary for their existence and operation  message received by the system, which does not change the amount of knowledge, does not fulfill the informative function

Decision-making function  decision-making function consists in delivering the necessary information to the decision-maker in order to make the decision  it is of considerable importance if it reduces uncertainty about the impact of actions taken, if it reduces the number of options that should be considered or increases the likelihood of desired events (e.g. business)  information should cover the problem of decision-making as well as procedures, possible to use when making decisions

Controlling function  Information transmitted to the recipient results in his specific behavior, in other words the sender of information is trying (with varying force and often with varying degrees of success) to influence the stance (ideas, actions) of another person or persons. The sender determines the recipients of information and the channel of information, through which he passes the message.  In the controlling function the users of information are both the sender and the recipient. For the sender the information is an instrument of control exercised over the recipient, the recipient can view the information in different ways: as a control tool, as an expansion of the knowledge base, as the information supporting the decision-making process.  depending on the sender, the information is forwarded to specific users or to a group of users who are not identified individually.

Conditions for application of information management I  the increasing role of information in the efficient implementation of more and more complex business processes. Information is the resource, or the goods - in companies providing information services, treated as company’s assets which is of the operational as well as tactical importance, allowing efficient servicing of the company’s current operations, but more often it is the resource of strategic importance enabling the development and facing the ever-increasing competition in the market. Information becomes a more important action factor than land, capital and labor activity, traditionally accepted in the economy  the general trend of the increase in the complexity of the information mapping the surrounding reality and the "world". Modern organizations (companies, institutions, etc.) operate in an increasingly complex information environment in which there occurs rapid development of the information services sector: a number of sources of information useful in, among others, effective management processes is growing, the diversity of available information (often with innovative features) is systematically increasing, we observe the increase in the intensity of information streams together with the very dynamic development of the diversity of information processes

Conditions for application of information management II  the specific nature of the information as a production factor. Information is a specific resource, due to its specific general characteristics, i.e. its intangible nature, proneness to distortion etc., diversity of functions and its huge variety  dynamic development of information technologies and their applications in practical implementation of information processes. The use of modern IT technology in the implementation of information processes generates specific (with regard to technologies and applied detailed IT solutions) areas and problems related to information management,

Knowledge management  general principles, techniques, systems and devices which define the information and communication structure of the business object  instrument supporting strategy development of the organization, as well as an integrated element of this strategy and depending on it

Information management process  comprehensive in terms of scope and sequence of activities dealing with all the data processing functions (raw and primary) in order to obtain - after proper processing and interpreting - useful economic information.  the basic data processing functions:  generation  collection,  storage,  protection  transfer (upload)  sharing data or information

Types of knowledge in the organization  tacit knowledge (also called silent knowledge) is associated with a person (employee); it is difficult to identify, pass or codify and, in consequence, to use  explicit knowledge (also referred to as accessible or formal); it can be expressed with different meanings, we can save, store, process and share it  we may also distinguish two approaches to creating knowledge resources:  Western (traditional); explicit knowledge is preferred, which is associated with recording it in a database  Eastern (Japanese); the knowledge is perceived primarily as tacit knowledge, which is individual for a particular economic object and difficult to formalize or to pass on, but it has an impact on the value of the organization

Knowledge management  efficient use of all intangible assets, which is only possible through the implementation of specific processes using appropriate tools, where the state of the knowledge resources within a given business entity is also conditioned by available data and information  one of the objectives of knowledge management is to provide executives with required information at the right time to use it in the decision-making process

Knowledge management processes I  locating knowledge - ways to search for information and acquire knowledge both within the organization and in its environment, where available tools allow you to identify internal and external sources of information as well as the sources of primary and secondary information,  acquiring knowledge - it should be carried out based on an analysis of information needs of a particular business organization  storing knowledge - which include processes related to selection, storage and updating of data which may be useful in the future, these activities help eliminate knowledge gaps in an economic organization; we use database and data warehouses for structured information

Knowledge management processes II  applying knowledge - a process of efficient use of existing knowledge in order to achieve the goals of a business entity, bringing economic effects  sharing and dissemination of knowledge - these are the processes by which single, isolated information and skills are transformed into knowledge resources which may be useful for the entire organization (including methods for creating and overseeing information networks based on modern technology), among the tasks of this process we can distinguish three categories: duplication of knowledge (i.e., presenting the same information to a large group of employees), sharing experiences from previously implemented projects and preparing relevant documents as well as sharing experience concerning ongoing projects, leading to the development of new knowledge  development of knowledge - includes any deliberate efforts to fill in competence gaps or create completely new competence, which exists neither in the organization nor outside

Business Information Systems

System definition  system – coordinated composition of elements, a set which constitutes a certain whole conditioned by stable, logical ordering of its constituent parts (Słownik języka polskiego WNT (Dictionary of Polish Language) 2004)

System definition cont.  the system which according to T. Tomaszewski is a collection of elements, connected by means of relations in such a way that they constitute one whole able to function in a particular way  The system’s features according to M. Macutkiewicz:  system elements interact with each other  system carries out particular functions  in the system we can differentiate smaller elements meeting the assumptions of the system - subsystems

System features I  system reliability is, generally speaking, probability with which the system presents the desired and predetermined behavior in a particular system  system adaptability is the property enabling it to respond to changing conditions and environment changes in a way which is favorable to its continued existence. Adaptability may be primary or secondary; the system also seeks to adapt to its surroundings. The system is adaptive if and only if, due to its behavior, it can maintain relevant data variables within the specified range. Important variables are the variables which the survival of the system depends on.  system intelligence is the property of the system which enables it to understand the causes and consequences of a change in feedback or size of the unit transferred via the connection and to use these insights to develop the system (Kisielnicki J., Sroka H., 2005, Systemy informacyjne biznesu, Warszawa, Placet)

System features II  learning of the system - process of a change of the structure, organization or features of the adaptation system, usually caused by repeated stimuli aiming at developing more effective system behavior.  correlation - a property of the system depending on the number and importance of coupling between the elements and relying on the fact that there are elements in the system, where the stimulus will bring about the reaction of a majority of other components.  equifinality of the system - a property that allows the system to achieve a given objective starting with different initial states,  self-organization of the system - allows the system to improve its own structure in order to achieve higher level of stability and adaptability. (Kisielnicki J., Sroka H., 2005, Systemy informacyjne biznesu, Warszawa, Placet)

System features III  system integration - the process of reducing differences between the elements (subsystems) of a given system, where some elements (subsystems) are combined in one component (subsystem).  system differentiation - is the process of increasing the differences between the elements (subsystems) of a particular system, in which certain elements (of the subsystem) can be further divided into several components (subsystems).  system centralization - process where one element of the system gradually becomes a leading element. The process where the importance of one element as a leading element in the system is gradually reduced is called the decentralization of the system. (Kisielnicki J., Sroka H., 2005, Systemy informacyjne biznesu, Warszawa, Placet)

System features IV  the collapse of the system – it is primarily the process of weakening linkages between elements of the system and the deterioration of the transformational properties of the elements leading to worse functioning of the system  the disintegration of the system – it is similar to the collapse of the system, where a particular stage permanently loses the capacity to perform its function  the repair of the system - replacing a part of the structure of the system with its exact copy or functional equivalent (Kisielnicki J., Sroka H., 2005, Systemy informacyjne biznesu, Warszawa, Placet)

System features V  system reproduction - replacing the primary system with a new system having the same or similar character. The system, which has the ability to replace some of its inadequate components with backup systems or components reproduced from the material derived from the environment of the system is called the self-repairing system.  system self-reproduction - the ability of a system to establish itself with the use of the material and energy of the environment.  system organization - the arrangement of system structure depending on the location, time and function. Its aim is to create an opportunity to demonstrate the desired (and sometimes a pre-determined) behavior. (Kisielnicki J., Sroka H., 2005, Systemy informacyjne biznesu, Warszawa, Placet)

Information system  ordered arrangement of the corresponding elements characterized by certain properties, mutually connected with specific relations  these elements are: information sender, information recipient, information sets, news channels and methods, techniques and technologies of processing information  properties of distinguished items and mutual relationships are fully revealed in a spatially and temporally structured processes of continuous information exchange, taking place both inside the object where the system operates, as well as in its surroundings  the system whose area of activity is widely understood economic object and its surroundings is referred to as Business Information System ( Wirtschaftinformationssystem )

Basic aspects of information system  internal, assuming its structural disaggregation, or seeing it as a set of components (static approach, because it is a description of states (structure) of the system)  external, perceiving it as a whole, or applying a deliberate aggregation of its architecture ( dynamic approach because it highlights the system functions )

Elements of information system information sender information recipients information sets information channels methods, techniques and technologies of information processing The structure of information system

Senders and recipients of information I  physical, organizational and legal information entities participating in the transmission and exchange of information  physical information entities are people, i.e. workers employed in a particular economic object or - more and more frequently - automatic transceivers, especially computer systems equipped with appropriate communication modules  the organizational entities are different cells of an economic object (individual workstations, sections, branches, faculties, departments, etc.), legal persons are the objects, seen as units in terms of formality, which are treated as separate entities

Senders and recipients of information  in the context of individual objects, as well as its external information exchanges we may observe a continuous variation of the system roles - the sender of the information, is also its recipient, and we frequently deal with information feedback  growing phenomenon of globalization of intra- and inter-economic relations, as well as the transformation of the business environment, causing changes in economic activities also contribute to the indicated interchangeability of roles, which can be exemplified by the changing information relationship between a buyer and a seller or a supplier and a customer within the systems such as online shops, electronic auctions and exchanges, or logistics and distribution networks

Information storage  sets of messages of an economic nature - in the form of a numerical (numeric), text (alphabetical or alphanumeric), graphic or audio (i.e. multimedia) - generated by information broadcasters in a specified spatial and temporal order of  together with the widening of the scope of the computerization of economic objects and the introduction of more and more advanced computer technology, collections of economic information (in-house and external) are more and more standardized data and messages sets with a strictly defined structure, content, characters and formats  they are generated or updated upon the occurrence of certain causes (e.g. the economic past events or the events initiating specific business processes) or at specified dates (e.g. at the end of the month or at the end of the year)

Basic types of information sets in business information systems Grouping criterionThe distinguished groups of information sets The place in the processinginput internal (intrasystem) output The degree of processingsource (primary) intermediate (temporary) result/outcome Type (form)numerical text (alphabetic and alphanumeric) multimedia The way of describing an economic phenomenon identifying quantifying The level of volatilityfixed relatively stable variable (transactional)

Information channels  formal and informal routes of information flows, representing registration or information mapping of (physical and financial) inflows, both within the business object, as well as building relationships with its surroundings  formalized information channels are such ways of documents circulation and the procedures of performed tasks, which take the form of binding rules or instructions specifying the senders and recipients of specific information, the places of carrying out specific processing operations, agents responsible for them and the time frame (dates, times) for their execution  in any information system, in addition to formal information channels there are also ways of their informal circulation which must be identified and taken into account by digitizing economic objects, which can markedly hinder the process of computerization

Business Communication System The communication system consists of 4 elements:  information of the sender  information of the recipient  information sets  information channels

Methods, techniques and technologies of information processing  algorithmised procedures and formalized rules for automatic and non- automatic (traditional) processing of collections of information which - on the way from the sender to the recipient (i.e. from the source form to the resultant form) - are wholly or partially subject to the necessary functional transformations (registration, storage, control, transmission, presentation, etc., and arithmetic and logical operations)  they divided into two basic groups:  traditional (non-IT), in which information and communication processes are performed using manual techniques and technologies  IT (computer), in which these processes are executed with techniques and computer technologies

Information system - dynamic approach Information system functions collecting information processing information storing information sending information presenting information

Collecting information I  its essence is the collecting, registering and recording data and economic messages, i.e. supplying information to an economic object and its individual organizational units (input / provisioning information system)  data identifying and describing the quantity, value and quality of business operations are collected in accordance with regulations governing records of economic events (the Act on accounting, tax law, economy, customs etc.), recorded on a dedicated device registration (forms, documents, "manual” records, various computer storage media, etc.) and ordered as sets of data on the structure and content normalized by earlier indicated laws and regulations and internal regulations and acts, where the most important element is the chart of business accounts

Collecting information II  when collecting data, the data and their collections are subject to secondary operations, such as: content and formal control (e.g. the type, length and internal structure of data, their unique values or the acceptable limit values, and consistency, completeness or non-contradiction). Frequently it is necessary to carry out the data conversion (changing their form or their media) and their coding (replacing the usual names and values with unique codes - symbols - in order to ensure their clarity or record them in a more compact form)  in most business information systems input and related implemented processing operations are the most labor-intensive link. Many of these steps are performed "manually" (the classic example is the introduction of business transactions using keyboard devices)  input operations contribute to about 80% of the errors of the data entered into information systems (transcription, transposition, distortion, omission, addition errors etc., and errors associated with a certain unreliability of automatic identification and reading devices, especially when data recorded on devices do not meet the requirements of a particular technology)

Processing information  performing common arithmetic (addition, subtraction, multiplication, division, etc.) and logical operations (establishing relations of equality, majority or minority, organizing data sets on the basis of established relationships etc.)  Processed information is used to supply sets of information (their update and modification), and to allow the use of filtered, properly structured and aggregated compilations of information and decision-making processes

Storing information I  data stored on durable media (paper, magnetic, optical devices) in the shape and in the form enabling them to be easily used in the subsequent transformation process without having to carry out input operations (e.g. by placing these records on computer memory devices)  the data we store in the short- and medium-term are stable or relatively stable sets of data, transaction sets (business operations descriptions), processing algorithms sets (programs) as well as various processing parameters (e.g. dictionaries and tables of values)

Storing information II  long-term storage, called archiving, aims to protect the data files against accidental loss (by producing and keeping copies) and to store the information which in accordance with legal regulations are to be kept for several years on a fixed media. Stored, and archived information is often subject to additional auxiliary operations, such as compression (reducing their volume in order to reduce the need for media) or encryption (their conversion enables its confidentiality)

Presenting information  providing customers with the necessary resultant information required within the time limits, place, scope, form, cross-sections and degree of detail (aggregation), and therefore is often called information system output  the scope and quality of the information issued by the system represent one of the most important criteria for developing of the system and during its use. Modern systems are not created in order to register all the data on economic events. Their primary purpose is to inform, so that at the right time could make the right economic decisions  properly structured output is to enable free extraction of data on demand (e.g. by query languages or report generators) and transfer the downloaded data to other programs for further processing (e.g. their multi- sectional analysis or visualization)

Sending information  Transmission of information can be divided inot two groups:  transfer of information resources between organizational units performing other object processing operations ( inner-processes, information and communication processes )  the exchange of information between an object and its environment ( external information and communication processes )  The transmitted information is often subject to such auxiliary operations, as their additional ordering and completing (e.g. within a package, connected with a specific type of business events, recipient or sender), conversion to a form and / or carrier associated with a given information channel (e.g. adaptation to requirements of the transmission in a network of a specific standard) or the compression and encryption (for purposes similar to those achieved in the case of storage)

Qualitative characteristics of the resulting information Reliabilitythe resulting information must accurately (as appropriate) describe the operations (events) business and their consequences Selectivitythe resulting information should be selected taking into account the characteristics of the problem or the applied management method (both their scarcity and excess are negative phenomena) Addressabilitythe scope, accuracy and timeliness of information must be adapted to individual needs of a given recipient, designated by the nature of the tasks performed by him Suitabilitycompliance with specific needs concerning information (obtainable by providing customers with tools for their search, filtering, extraction and presentation) Timelinessproviding information upon request (ad hoc), at the right time (at a time when a decision is to be made) or strictly defined terms (concerning the data and periodical information) Required formthe manner of presentation (alphanumeric - text or tabular, graphical, static and / or dynamic), details (elementary or aggregated data, summaries levels), the media (screen, print, magnetic or optical media) in accordance with the requirements of a specific recipient

Research methods of business information systems  Structuring of the information system  Process approach in information systems

Information system structuring  cross-sectional (layered) identification, analysis and/or modeling of the most important components of an information system and their processes  based on the SADT (Structural Analysis and Design Technology methodology) we can distinguish 4 sections (structure):  functional  informative  technical and technological  spatial

Functional structure  a set of goals and objectives of the system and their mutual interdependence (primary function in relation to other structures)  it creates direct links between an information system and productive and managerial business functions in the system  object mission -> object goals -> objectives of the production and management system -> information system goals -> objectives of the information system  functional structure can be analyzed according to the following criteria:  cross-section of the organizational structure (according to the organization chart of the object)  cross-section of the structure of business processes (including financial, logistics, production, distribution processes etc. as well as subsequent actions within the value chains)

Functional structure – analysis criteria  presentation of the organizational structure (according to the organization object chart), enables  reference of objectives and tasks of an information system to the elements of the organizational structure of the object, allowing them to draw up a "map" based on this structure  preparation of detailed analysis and conclusions concerning the restructuring (reorganization) of companies to streamline information and communication processes  presentation of the structure of business processes  ( including financial, logistics, production, distribution processes, etc. and also including the actions in the proper order of the value chains);  It allows to define information and communication objectives and tasks in particular distinguished areas of the activity of the economic object

The presentation of the structure of business processes - example  Achieving the goal of increasing the timeliness of the deliveries by 90% can be divided into the following tasks: a)defining structures of products and material transactions, b)production database management c)sales planning and production in various time zones, including continuous planning, d)capacity planning, e)production scheduling and control f)demand management and distribution planning, g)material requirements of planning and carrying out material and technical supplies, including accepting deliveries with elements of quality control, h)inventory management and work-in-progress, etc.

Information structure The information structure includes: information resources  in the classic structural approach there are sets of input data, basic (system, internal) sets, output information sets, as well as procedures of their transformation (algorithms) in the system: entry -> collections -> output  all the selected elements can be presented at different levels of detail. Their identification process should always include such elements as: name, content, reference to the elements of the functional structure which they create, update, process, emit, etc.  meta-informational layer, which is a collection of information resources of the system (resource directory included in the system)

Information structure and functional structure  information structure of the system is directly linked to its functional structure  the performance of each system function and task involves specific elements of information structure in the process  establishing of a functional structure allows the reproduction of the system information structure  an accurate description of the information structure of the system allows to verify the functions and tasks from the point of view of their completeness, absoluteness, accessibility and necessary information resources

Technical and technological structure  it is formed from technical resources, software and ICT applied in the processing  it should be consistent with functional and informative structures, i.e. it should provide free execution of the functions and processing tasks specified in the functional structure and, simultaneously, it should handle ( store and process ) information resources defined in the information structure.  the key requirement for the selection of technical measures, software and related information technology should be the necessity to adjust the hardware, software and technologies they use to functional and information requirements of the economic system, rather than adapting the system to the capabilities and/or limitations of hardware, software or technology

Spatial structure  set of environmental (usually geographic) locations, where system objects are distributed, the objects are defined in the three previous structures, i.e. the functional, informational, technical and technological  they include:  production and management units  places of creation, collection, storage, processing, storage, transmission and emission of data and information  location of processing procedures  arrangement of the applied technical resources, software and information technology  spatial structure determines the distribution of resources and elements of the system in the environment and the principles and methods of mutual relations

Process approach  sources of process models used in modern business information systems and in application systems supporting them are as follows:  operational reference models  best business practices

Diagram of the production of made-to- order goods CLIENT requirements Transfer of resources Information flow Information flow Information flow Information flow Information flow Information flow Production Transfer of goods Sale Sale of goods CLIENT Meeting the requirements Collecting orders Design Information flow Purchase PRODUCT REALISATION

Supply Chain Organization Reference Model (SCOR)  business activity is seen as a string of interrelated processes creating value chains and/or logistics chains connecting suppliers, manufacturers, shippers and recipients, where all participants cooperate in order to achieve maximum benefit  in the narrow sense it concerns all activities inside the economic object, where - in the first place – the divisions into the technical-economic segments and constituent elements of the organizational structure cease to be relevant, and the smooth flow of resources and information along the manufacturing or service chain become the ultimate goal, and then cooperation extends beyond the object, integrating its immediate economic environment (especially suppliers and customers)  in a broader sense we refer to the so-called extended enterprise network involving the entire network of cooperating economic objects

The application of a process approach  The application of a process approach in an enterprise requires:  the adaptation of the generalized models of business processes to the requirements and constraints of specific business objects  the use of best practices in information systems in order to ensure optimal cooperation between employees involved in the handling process  The details and specification follow the pattern presented below (top- down approach) generalized model of business processes → is transformed into process model of economic object → is mapped in the form → modules (or other structural elements) of object-oriented information system → are reproduced in the form of → components (or other components of business architecture) of information system

The idea of the process approach in business information systems process model of economic object information system modules Information system components generalised model of economic processes best practices of management of the supply chain and the SCOR model SCOR object model object- oriented logistic structures EDI/EWD e-EDI B2B SCM e-SCM SRM e-SRM purchase planning registering orders consolidation of orders quality control of deliveries warehouse receipts tracking deliveries analysis and selection of suppliers service providers directory

Typology of information system  The variety of information systems occurring in business practice and the associated functions necessitate the application relevant typology for these systems

The criteria for the distribution of information systems  operating scale  the contents of the system  system generation  the level of support (intelligence solutions)  scope (level of complexity)  degree of integration  degree of versatility  connection with the electronic economy

Information systems according to the functioning scale  macroeconomic systems  supra-object  inter-object  microeconomic (object) systems

Macroeconomic information systems  they cover the area of a country or a region or provide information or help to particular sectors or industries (e.g. public administration, statistical records)  they are divided based on the scale of the operation and the need to take into account the heterogeneity of supported objects (e.g. the need to standardize procedures, data structures, transactions and business communications)  a large part of the macroeconomic systems starts to have an international scope (e.g. statistical systems operating in the European Union or banks servicing the European Monetary Union and the euro) or even global (e.g. systems used to locate and identify objects involved in extended logistics and distribution chains)  these systems are more and more frequently using open standards for information and communication

Microeconomic (object) information systems  they are associated with the operation of separate business or administrative units  they constitute a vast majority of business information systems  their substantive, object or technology diversity is the greatest, due to, among others:  diversity of ownership (state-owned entities, private, cooperative, local government units, etc.)  scope of activity (production, trade in goods, banking and finance, insurance, state and local administration, services, information institutions etc.)  size (from individuals to multinationals)  dispersion (from local to those operating in a large area)

Information systems according to sectors We may distinguish the following support systems:  production (manufacturing)  logistics and distribution (procurement, supplier relationship management, shipping and transport, material management, sales)  management of corporate financial resources (accounting, cost accounting, budgeting, controlling, financial analyses, reporting)  management and administration (strategic, tactical and operational levels)  trade in goods (retail, wholesale and stock exchange listings, marketing, customer relationship management)  banking (current accounts, deposits, loans, interbank operations)  public administration (statistics, population, vehicles, taxes, land and real estate registers)

Information systems according to generation  transactional (involved in collecting, processing, storing, updating and sharing data related to all events (transactions) which occur in business organization)  informational and analytical (the goal is to provide information from the database of transaction systems in the form which effectively supports decision-making)  consulting (directly supporting the decision-making process)

Information systems according to the level of user support  recording and reporting systems, acting primarily at the transactional level (they record all the required data concerning business transactions and issue standard, mainly periodic reports); we distinguish single- and multi-disciplinary systems  information and decision systems, set "over" transaction systems, using the data resources at the informational-analytical level (to help decision-makers, especially at the operational and tactical level of management); we distinguish information and decision support systems,  Business Intelligence systems, which represent a new class of information systems using different, smart technologies, storage, processing and presenting data and economic information, focused on the integration of corporate knowledge

Information systems according to the subject- matter (degree of complexity)  monothematic systems (easy, not comprehensive); they do not support the full range of subjects (functions, tasks and information resources) from a particular area; thematic areas are defined at the upper level. This is due to the difficulty concerning the algorithmization of certain procedures due to their volatility, imprecision or ambiguity, or for economic reasons (the application of the systems used in certain areas of modern information technology is still too expensive, especially with regard to actual information needs of managers and realizable benefits)  comprehensive systems ; they fully (or almost fully) cover a particular area with regard to the subject-matter involved, both in terms of functional and informative approach. This situation is typical for systems supporting e.g. banking products and processes or well-structured business processes in enterprises, for example, warehouse management and integrated solutions for multiple applications based on MRPII / ERP class applications

The complexity of information systems against the value chain input logistics human resources management technology and development supply production output logistics marketing and sales services organization infrastructure added value (financial result) basic functions auxiliary functions Office systems HR systems CAE, CAD and CAM systems on-line shopping systems after-sales services on-line and CRM sales systems on-line ordering systems MRPII, PLM, FMS systems warehouse systems

Information systems according to the integration level  integrated, i.e. meeting the conditions of functional, informational and technological integration  non-integrated, where there are no strong relations between functional, information or technology (autonomous systems)

Three aspects of integration  functional integration - is a measure of the consistency of the system procedures and the interrelationships between various areas in the system; note: integration within the economic process chains and / or value chains is most effective  information integration consists in the existence of close information links between interdependent functions, so as to minimize data redundancy, to arrive at their single input, as well as to the internal integrity of information resources (understood, on the one hand, at info-logical level due to sharing certain information resources by all relevant system functions and / or users, on the other hand, at data-logical level, according to the classical understanding of this concept in database technologies  technological integration - involves the use of a uniform system across the environment of hardware and software and technology that allows, among others, for the use of a particular user interface across all applications, and also freely exchange objects between them

Directions of integration  horizontal integration - connecting function, information and technology interdependent activity areas (e.g. payroll or purchases) or business process; characteristic of transactional systems, e.g. based on MRPII/ERP class applications  vertical integration – connecting transactional data (operations) with the information and decision needs of senior management levels; characteristic of modern information, research and advisory systems

Directions of integration – fig. horizontal integration vertical integration management support systems processing (support) operational tactical strategic data  information  decisions  knowledge transactions processes process chains business areas of technical and economic activity, functional areas and/or economic processes Internal integration, integration between management levels external integration between objects and its environment

Information systems according to the degree of universality  Non-standard (dedicated) systems are designed for a specific user and taking into account the reported requirements, needs and limitations  standard systems (repeatable, typical systems) are universal solutions within a particular class of applications

Individual systems  are usually designed when the user cannot find solutions on the market which would fully satisfy his needs  their implementation includes the full cycle of creation of an information system; the systems are adapted to the specific characteristics of a particular object and economic force in its processing procedures, they take into account the organizational, personnel, hardware or spatial limitations of the object  their use in other economic objects normally requires substantial changes in the system, and carrying out extensive work in the facility adaptation  defects:  generally higher cost, due to the fact that all the costs associated with the design work and programming must be covered by the ordering part  hidden faults, e.g. new, untested technological solutions, errors appearing in the analysis etc. which cannot be corrected by past experience

Standard systems  due to the adopted assumptions that the systems will be operated by many different users under different circumstances, the systems will be designed taking into account the requirements concerning their repetitiveness and their flexibility  repetitiveness of information systems is achieved in two basic ways: - forms - particularly when these systems are simple - based on the functional assumptions of office toolkits, such as e.g. spreadsheets or simple database management systems - they are designed as a system of flexible, highly parameterized and thus implementable in various business objects

Standard systems – aspects of flexibility  construction - relating to the possibility of shaping (during installation) and modifying (during operation) of the structure and the functional scope of the system  information - associated with the possibilities of defining and redefining structures processed and stored in the system, and thus, its information structure  procedure (algorithmic) – connected with the possibility of introducing changes in processing procedures, their modification and expansion

Information systems and e-commerce  not connected with e-commerce (web autonomic), i.e. functioning exclusively in the so-called non-network economic environment (most frequently connected with traditional industries and services or with specific, selected area of activity in enterprises and/or institutions), we should not that such systems will be less and less common in the future  cooperating with e-commerce (web enabled), constituting usually extensions of existing solutions with appropriate interface and/or other access solutions, enabling the use of network to conduct some forms of economic activity – it is at the moment and probably continue to be the basic, most common group of systems  fully embedded in the area of e-commerce (web-based ), acting only in an environment network and the Internet and designed at functional, informational, technical and technological levels in line with the strategy and methodologies to create e-business systems; the importance of this group of business information systems is growing steadily, both in volume and in relation to the role in gaining the so-called competitive advantage and in implementing of new models of the enlarged integration and economic

Hardware

Computer  A computer is an electronic machine ( device ), used for automated processing of all data that can be stored in a digital form. An important feature that distinguishes a computer from other similar devices (e.g. simple calculators) is its programmability, which means that the implementation of specific tasks (e.g. calculation) is connected with the tasks performed by programs stored on the computer memory

Hardware and computer system  Hardware - computer and cooperating peripherals (e.g. monitor, printer, scanner)  Computer system - a combination of hardware, software, data, algorithms and people operating in this environment

Calculations perfomed by a computers  Computers are built using electronic components, which can be divided into two basic conditions: the flow of current, or lack thereof  This state of affairs determined the choice concerning the presentation of data on a PC using two distinguished states: ones and zeros (conventionally referred to as bits ). Therefore, the calculations performed by the computer are performed using a binary representation of numbers, or the binary syste m

Bit and Byte  Bit (abbr. bi nary digi t ) - LU; the smallest amount of information needed to determine which of two equally probable states was adopted bya system  Byte - the smallest addressable unit of information in a computer memory, consisting of bits (in practice, it is assumed that one byte equals eight bits ) Multiplicity of bits NameSymbolCoefficient kilobitkb10 3 megabitMb10 6 gigabitGb10 9 terabitTb10 12 petabitPb10 15 Multiplicity of bytes NameSymbolCoefficient kilobytekB/KB10 3 megabyteMB10 6 gigabyteGB10 9 terabyteTB10 12 petabytePB10 15

Computer Central processing unit is a set of devices performing main computation activities and control the operation of the entire computer CPU Internal memory RAM and ROM ALU Aritmetic Logic Unit Register set Input-output system Control system I/O devices

Internal memory  The central unit is a set of devices performing main computation activities and controlling the operation of the entire computer. The base unit includes internal memory, the processor and input-output system. The internal memory is used to store data in the form of a string of zero and one digits and programs executed by the computer. The internal memory includes:  RAM (Random Access Memory) - RAM or computer main memory; It is used to temporarily store instructions and arguments necessary for the CPU operations, especially for storing software, instructions and data required for proper operation of the program and for temporarily storing the incoming data and the data generated by the processor  ROM (Read Only Memory) - permanently stores all the instructions and commands needed to properly start your computer. This memory does not erase the information in the event of a power failure. It is used to start the computer and stores the instructions for proper operation of input-output devices, i.e. BIOS (Basic Input / Output System)

Processor - CPU (Central Procesor Unit)  The processor determines majority of actions taking place during computer operations and manages them; it consists of logical blocks: arithmometer system, control system and procesor registers  Arithmometer system (or arithmetic logic unit) is used to perform simple arithmetic and logical operations. The results of these operations are stored in RAM.  The processor registers are used to temporarily store operands for the time needed to perform arithmetic or logic operations. A control unit “fetches” instructions from memory and reduces the number of readings and instructions from external memory, which in turn speeds up the computer.  The control system ensures cooperation of other functional units in order to complete the program in the memory. First instructions are then drawn from memory, then decoded, they calculate the cell addresses (in memory) containing operands and forwarding them to arithmometer to perform calculations. This sequence of operations is called the cycle of CPU and is one of the parameters defining the performance of its work. The number of cycles per second depends on the internal clock speed of the CPU. The higher clock frequency, the greater the number of cycles will be performed, and thus the speed of the computer will be greater. The frequency of the clock is measured in MHz (1 MHz = 1 million CPU cycles per second).

Input-output system  PC is used for communication with its surroundings. It is used to input programs and data, outputting the results and communicating with the operator  The processor and internal memory are connected by a so- called system bus (Front Side Bus - FSB), which is the structure of links used to exchange of information between the two components of the computer. The speed of the bus determines the frequency of the system clock, which is expressed in GHz

Theoretical basics of computer construction  Alan Turing "On computable numbers" - the first theoretical model of a computer, or an abstract machine, which was able to perform a programmed mathematical operation. Depending on instructions stored on a tape, it could perform any operation (i.e. a Turing machine ). In the same work he presented the first computer diagram based on the ideas developed by Charles Babbage (differential machine and analytical machine) John von Neumann developed the concept based on the following assumptions:  finite and functionally complete list of commands the possibility of software input into the computer system through an external device and stored in the memory in the same way as data  data and instructions should be equally available to the processor  information is processed through sequential reading of instruction from computer memory and carrying out those instructions in the processor

Most important events in the history of computer equipment development  1943-1945 In Philadelphia he ENIAC (Electronic Numerical interpreter and calculator), the world's first computer is created, constructed by JP Eckert and J. W. Mauchly at the University of Pennsylvania, ballistic calculations for the US Navy  1947 - Employees of Bell Telephone Laboratories, William Bradford Shockley, J. Bardeen and WH Brattain invent the transistor, they receive the Nobel Prize for the invention in 1956  1953 - IBM PC 650 is introduced to the market on a massive sale  1954 – a first printer, Uniprinter is invented  1964 - Gordon Moore suggests that the level of integration of computer systems (CPU performance) doubles every year (ie., Moore's Law)  1967 - IBM develops the first floppy disk  1971 - Ted Hoff, S. Mazor, and F. Fagin draw up a 4-bit Intel 4004 first microprocessor running at a frequency of 108 kHz  1977 - The company Commodore Business Machines presents PET 2001 computer with a processor 6502, 4KB RAM, 14KB ROM, keyboard, monitor and tape recorder  1981 - The first of IBM's personal computer sold worldwide with great success  2001 – A first microprocessor appears, the Intel Pentium 4 series. Tere is a significant increase in the production of microchips designed for mobile computers  2004 – A significant decline in prices of computer monitors, LCD, which is eliminating traditional CRT monitors from the market  2006 – Integrated mobile devices (such as a smartphone, PDA GPS) are increasingly cheaper  2007 - Presentation of the theoretical basis of production of netbooks

Next steps??  Use of touch screens on a large scale  Motion control  Mind control  …..

Generations of computers  Generation 0. The zero generation computers are machines designed in the mid-thirties of the twentieth century with the capabilities of today's simple programmable calculators. Their basic feature was the lack of electronic components, because they were built with the use of mechanical (i.e. Computer Z1) or electromagnetic (e.g. Relay Z3) parts.  Generation 1. Computer used the first generation of electron tubes, i.e. the first electronic active components used to magnify, generate or convert electrical signals. The most famous computer generation, the US Electronic Numerical Integrator and Computer (ENIAC) was built in the years 1943- 1945.  Generation 2. The second-generation computers were computers constructed in the fifties of the twentieth century based on transistors, semiconductor or electronic components which had the ability to amplify the electrical signal. An example of such a computer is Polish ZAM 41  Generation 3. The third-generation computers were built using integrated circuits of small and medium- scale integration, or chip containing from a few to a few hundred basic electronic components such as transistors, resistors, diodes and capacitors. These computers were created in the sixties of the last century, also in Poland (e.g. Odra 1305).  Generation 4. The fourth-generation computer were computers built based on a large and very large scale integration, or those containing from a few thousand to several million basic electronic components (i.e. transistors). It is generally assumed that this generation continues to the present day, however, some authors also speak of the fifth generation of computers, which use e.g. unconventional and experimental technology used to build e.g. optical, quantum computers or the devices based on protein structures

Three basic classes of computers  Division according to price and computing capacity (the number of computational operations performed per unit of time, measured by units called flops - Floating Operations Per Second):  supercomputers (power of at least several dozen Teraflops)  central computers (mainframes, which support the work of groups from a few dozen to several thousand positions)  microcomputers (workstations, personal microcomputers, notebooks, netbooks, PDAs)

Division of basic computer devices Urządzenia komputerowe wprowadzania danych klawiatury czytniki skanery urządzenia sterujące wskaźnikami cyfrowe kamery i aparaty fotograficzne przetwarzania danych procesor pamięć wewnętrzna układ (kanał) wejścia-wyjścia przechowywania danych (pamięci zewnętrzne) na taśmach na dyskietkach na dyskach twardych na dyskach optycznych na kartach (flash) transmisji danych modemy karty sieciowe koncentratory (hub) przełączniki (switch) routery wyprowadzania danych urządzenia generujące obraz i dźwięk monitory drukarki plotery Computer devices data capture data processing data storage external memory data transmission data output keyboardsprocessor readers scanners internal memory channel of the input -output controllers with indicators digital cameras on tapes on floppy disks on hard disks on optical disks on flash cards modems network cards hubs switches routers media devices monitors printers plotters

Representation of data and algorithmization

Types of data  A particular type of data is characterized by a set of values (which may be adopted by the indicated fixed, variable or expression) and the set of operations (that can be made based on this fixed, variable or expression)  We distinguish: simple types, structure, data type and subject

A simple (scalar) type A simple data type contains a single value and we distinguish:  Ordering/historical type, where we have:  Integer type – represents a set of integers, on which you can perform arithmetic operations,  Boolean logical type - a set of two Boolean values (i.e. boolean), which is the value of truth and falsehood; we do not perform arithmetic operations on this type of data, only logical operations (e.g. alternative, conjunction, negation)  Character type - it represents the character sets of specified values, e.g. a set of ASCII characters, where the character is every symbol which can be typed using the keyboard  Enumeration type - a set defined by a small number of elements that are identified by unique names which do not carry any other substantial meaning  Restricted type - certain range of other ordering types, i.e. generally limited range of acceptable values within integer or character types  Real type (also called floating-point) - it represents subsets of real numbers (partial and fractional) with varying accuracy  String type (also called text type) – contains a string of arbitrary characters, which is treated as an array of characters

Data structure  Data structure is a type of complex with any degree of nesting data, meaning their design, construction, internal links, relationships, etc. We distinguish the following basic data structures:  Array - is a structure of data which groups the elements of the same type (i.e. homogeneous structure), where the size of array type is defined in the definition of the index ranges. All the data in the array carry the same name, and we distinguish them from one another through indices. It is the oldest historically structured type. We distinguish the following categories of array:  one-dimensional (also referred to as vectors) or single-index  multidimensional (also called matrices), where you have to use a few indexes to select the specific value in the array; two-dimensional array is most frequently used  Record - it is a data structure grouping any of the components (i.e. fields), which can be of various types (forming a heterogeneous structure). It is a structure bringing together the different types of data into one unit  The set structure - is a data structure consisting of some of the conditions set (including all or none) elements of the ordering type  File - this is a data structure of the same type, where the number of its components varies, depending on the course of program execution. Files are identified by their names

Algorithm  algorithm (in general) is a coordinated set of accurate, unambiguous and executed commands used to obtain correct - if possible - arrangements in a finite time (Muhammed Alchwarizmi - the person believed to have develop an algorithm for addition, subtraction, multiplication and division with integers)  algorithm (in computer science) is a finite and ordered sequence of processing operations (instructions, operations, orders), used to convert the set (setss) of data input into output data

Scheme processing algorithm Set (sets) of input data Set (sets) of output data ALGORITHM Declarative part (definitions of names, formats and data values) Procedural part (definition of processing sequence)

Algorithms rules  effectiveness - guarantees finding a solution if the initial conditions are not mutually contradictory and, at least theoretically, allow for his discovery of  finiteness (also called a stopping rule) - it indicates that the algorithm is composed of a finite sequence of the number of elementary operations (such as arithmetic, logic, comparison, etc.).  universality (also known as mass production rule) - the algorithm is extremely generalized to allow all options to solve a given task, and not just the specific case concerning repeatability – it leads to the same results regardless of the person carrying out the algorithm of  uniqueness (also known as the rule of specificity) – it specifies exactly the type and order of operations to be carried out  sequencing (also called validation rule) - there is a proper sequence of operations and there is a clearly defined agenda  rationality (also called rule of effectiveness) - performance of a task is carried out by the shortest possible route and at the lowest cost to arrive at the solution in the event with the minimum number of operations involved  detail - contains a description of the objects and activities that are clear and enforceable by each potential contractor

Types of algorithms according to the criterion of operation sequencing  linear (also known as simple or sequential), where we are dealing with unconditional execution of the subsequent steps (e.g. algorithm for adding two numbers)  branched (also known as a forking algorithm), where there is at least one conditional expression (e.g. algorithm for dividing two numbers where you need to check whether the divisor - the denominator - it is not zero; if so, we should state: no results unless we perform a division and give the result of the operation)  repeated (also called a loop), where we have a repeated execution of these same instructions resulting from applying at least one condition, where we distinguish here:  cycle, i.e. a predetermined recurrence of the activities during - before the start of the loop, for example: an algorithm which calculates the sum of n values (n is the number introduced at the start of this algorithm)  iterations, i.e. the sequence of activities is carried out as long as there will be no veracity posed condition, for example: arithmetic mean of n positive numbers (values are added until it is n positive numbers, we enter both the positive and negative number)

The methods of recording and presenting algorithm  graphical methods based on the languages of graphic symbols  descriptive methods (verbal) based on ethnic language or so-called industry-specific languages (e.g. for use in financial and accounting regulations or legislation) and formal languages (e.g. the language of mathematical analysis or programming languages)

Graphical methods  flowcharts (also called network activities or patterns of activity)  processing schemes (also known as schematic diagrams of systems or waveforms)  decision tables (logical decision tables)  decision trees  cross tables techniques of decision making

The use of graphical methods  a flowchart (block diagram)- used to disclose the type and sequence of performed operations  processing scheme - useful in describing and agreeing the tasks with the future users of the program (a sequence of operations performed by the system)  decision table - useful during agreeing requirements and tasks with users of the designed program (presentation of choosing one activity from a large set of activities or undertaking actions dependent on multiple conditions)  decision tree - used during agreeing the requirements and tasks with the users of the designed program (with complex decision problems and making strategic decisions with high level of risk involved it allows for making decisions and creating an action plan)  cross table - useful to present interdependencies that may occur between events and relevant prior consultation with users

Flowchart (block diagram)  graphical representation of the type and sequence of work (operations) resulting from the algorithm applied for solving the problem  it is created using standard graphic symbols (building blocks) whose shape determines the type of actions (operations), and the text inside the symbol clarifies this action and defines its parameters  blocks forming a flowchart are combined with arrows showing the main steps which constitute the selected algorithm. The decision block can be built in a form that allows checking the condition of multi-state, i.e. with more than two possible outputs (e.g. with three options :> 0, = 0, <0). However, any such item can be replaced by a sequence of simple (binary) conditions. Most of the symbols may have one or more inputs and only one output. The exceptions are:  symbols of the start that have no input and only one output  symbols of the end, which may have multiple inputs, but have no choice  decision blocks, which can have multiple inputs and two outputs (yes, true or not, false)

Flowchart - blocks combination rule  each flowchart begins with the symbol with the word: Start, which occurs only once (this rule requires an unambiguous algorithm), with one arrow leading to the next item which orders the first step in the algorithm, and there is no line proceeding it  the flowchart ends with the word: Stop, perhaps with several ends, as the algorithm may have several "paths", each of them must end with this block (efficiency rule); this symbol may be the final stage of several lines, but there is no line exceeding it  there may be a number of arrows leading to a particular stage, and each arrow shows the “execution pattern" with the action (operation) indicated inside every stage  each symbol can start with one arrow, with the exception of a decision symbol; apart from the decision-making symbol where we have two arrows, denoted by "Yes" and "No" (except for situations where there are multi-state decision symbol)  terminal symbol and connector do not have one of the arrows: reaching or outgoing, all the other symbols must have arrows: upwards and downwards  The symbols should be attached to the diagram in the "natural" order, i.e. from top to bottom and from left to right (other connections should occur incidentally)

Symbole graficzne w schemacie blokowym NameSymbolDescriptionExample Terminal symbolRepresents a start or end point of an algorithm (sometimes also stopping of the action, possibly a start or end of a subprogramme). Input/Output parallelogram Denotes the process (operation) of entering data and assigning variables used in the later part of the algorithms or an activity of entering the process results. Inside the building block we have a kind of activity and the input or output data. Process symbolDenotes a particular operation of entering the substitution or calculation, and as a result, we have at different value, form or place of data record. Inside the building block we define the type of calculation (or substitutions) operations and the variables in this operation. Decision symbolDenotes a choice of two variants of the algorithm, made on the basis of checking the condition presented inside the building block. Arrows on the sides should indicate Yes or No pointing to the variant chosen when the condition is met or the one selected when the condition is not fulfilled. AnnotationRepresents comments or remarks for the user of the flowchart which help the user to understand the parts of the flowchart. On-page and off- page Connectors Used to connect separate parts of the flowchart which appear on the same pages (on-page connector) or separate pages (off-page connector). Complementary connectors are denoted with the same comment inside (usually it is a natural number). STOP START STOP START READ X PRINT Y Y = X + 100 TN Calculating the average End of the set YesNoNo T N Y>0 1 1 1 1

Flowchart – list of names  Complex algorithms require the use of the table with names (descriptions), which contains the names of all the variables and constants used in the flowchart (input, auxiliary and output data), together with an explanation of their function

Processing scheme  processing scheme (also called the system diagram or flowchart) is primarily used to describe the technological process of individual data processing in the system  it presents the actual sequence of operations performed by the system  it consists of three parts, mostly placed in a table  in the first (graphic) part we show an algorithm of the processing of data in the system using an appropriate combination of symbols (each device and processing function has its own graphic sign) and the lines indicating the relationship between them  in the second (descriptive) part, we place a comment which is assigned to particular elements of the flowchart  In the third (optional) part we include a description which contains an explanation of the meaning of the standard symbols used Graphic schemeExplanation Description:

Symbole graficzne w schemacie przetwarzania SymbolExplanation Monitor and keyboard Disc set, disc or database Sorting Updating Input/output operation Procedure, operation in the computer memory Logical operation, decision block (predicate) Source documentation Report, printer Issuing reports

Decision table  decision table allows you to specify (in the appropriate tabular form) what actions we need to take under certain predetermined conditions, presenting a very illustrative method of complex dependencies and relationships  the basis for the construction of the decision table are causal relations (if.... then...)  a decision table contains four main blocks:  all terms are entered in the conditions description (Condition)  all actions (actions, operations) are entered in the activities description (Operation)  all possible combinations of conditions are placed on the conditions block (choice or rules), where we usually use symbols: Y (Yes), N (No) indicators, which are equivalent to Boolean constant and the symbol (empty)  all activities which will be taken up within the decision rules are indicated in the actions block (Decision)

Types of decision tables  full (complete, simple) tables contain all possible decision rules; in the Condition block there are only Boolean constants and Empty indication  reduced (simplified) tables contain only the so-called important rules  indirect tables are a transitional phase between a full table and a reduced table  extended tables: there are additional symbols characteristic of conditions which are associated with the algorithm described in Condition block

Reduction rules of decision tables  Logical elimination – eliminating the so-called mutually exclusive rules  Combining similar rules – the proces of omitting non-significant conditions, consisting in combining two identical conditions, except one row in Condition block, and the result is the same activity (we may see the condition where the rules differ as negligible, we enter the blank character '-' and the two rules can be replaced with one)  merging rules - by using ELSE (otherwise) rule, which consists in replacing all decision rules, except for those noted explicitly in the table (i.e. by specifying all conditions), with one common rule, meaning "in all other cases"

Decision tree  decision tree is a method enabling, among others, to present the process of implementation of the decision; thus, it is especially useful when choosing one activity from a large number of activities (similarly to the decision table method)  in this technique the conditions are indicated with series of tests from top to bottom or from left to right, creating a tree structure, where the nodes are the questions (or activities that meet the requirements) and bends (the so-called branches) are actions. The final decision (request) is reached in the final node of the tree.

Contingency table (cross tabulation)  contingency table - a two-dimensional table where in the headings of each column and rows we enter proper elements e.g. positions, functions, activities. We show the respective relations by inserting - in a specific row and column appropriate symbol or number  contingency table is created in two steps:  in the first case we determine elements and functions which are presented in the headings of columns and rows  in the second case, we indicate relationships between them

Contingency tables – division  character (most frequent use of X)  figure (the compound is expressed numerically, which also indicates the relationship between the elements presented in the table); in the case of these tables, it is advisable to give a description explaining the meaning of each value

Descriptive methods  description  mathematical notation  a description of the next steps  structural language  pseudocode

Verbal description  based on natural language - free description of formal procedures, not bound by conventions  it is used as a first, rather inaccurate description which presents a solution how a particular task can be solved, and it allows for the selection of appropriate detailed description methods. We use this description in the case of difficulties or if other forms of presentation prove inefficient

Mathematical notation  it is a formal description and it is used primarily to present how to solve mathematical problems.  using appropriate models and symbols (mathematical language), followed by a step-by- step presentation of the whole algorithm of a given task  the algorithm is used primarily to explain and solve mathematical problems and we treat this method as helpful in describing the procedure in question. We rarely resort to using it to present the algorithm pertaining to the solution of the entire task.

Description of next steps  a description of the next steps comprises the operations or sets of operations. They are numbered consecutively, and we indicate the order of subsequent steps. If there are no such guidelines, we assume that we need to proceed to the next step,  in addition, in the braces we put comments that are not part of the algorithm, but they are used to comment on the process and they allow understanding of other instructions  it is one of the most accurate methods used to describe the calculations (including mathematical calculations) and their sequence. It can be relatively easily - as compared to other methods - transformed into the source program. It is especially suited for the presentation of complex algorithmic solutions.

Structural language  a technique sometimes called the program description language or program specification language, a form of verbal notation that removes ambiguities without losing the advantages of natural language.  descriptions are very similar to programs written in the languages of the block structure (e.g. in Pascal)  this technique is mainly used in the analysis of information systems, where the record should be at the highest level, possibly independent of implementation

Pseudocodes  pseudocode - as opposed to structured language techniques - is a physical description, which, with a certain degree of formalization, makes it possible to automatically translate it to a computer program. It is a notation system, which informally expressed the ideas behind the algorithm being developed  it is used when the details of implementation are important for the success of the project  externally, this technique is very similar to programming languages, but it is easier to use due to the use of keywords in ethnic (Polish)  the advantage of this method is that, after "translating" keyword commands in the programming language, we obtain a ready program. It is most frequently used when presenting the procedural elements of the designed IT systems; however, with more complex tasks, it becomes less clear

Business Processes Algorithmization  Business Process Reengineering - streamlining business processes (groups of actions necessary to perform in order to reach goals), which generally consists in preparation for the organization digitalization  business process is mapped by means of flowcharts, where we distinguish activities (operations) and their interrelationships  process map - the scheme is designed for a selected, coherent part of the organization activity. It provides a basis to create more detailed descriptions of processing rules, parameters, execution and results obtained in the process  top level map - a general schematic diagram showing business processes and their interrelationships is the basis for process analysis at any organization

Examples of process management aided by software  http://www.boc-group.com/pl http://www.boc-group.com/pl  http://www.ids-scheer.pl/pl/ARIS http://www.ids-scheer.pl/pl/ARIS  http://www.tibco.com http://www.tibco.com

Process maps - standard symbols Denotes any kind of operation or task performer in the process Complex (general) operation: denotes a group of tasks or actions Delay: event connected with waiting or forming a line Denotes a decision: a task consisting in selecting between two options/branches (positive or negative) Multiple source documents (a packet of documents, usually paper documents) Result document (printed output), printout, report Input or output operation Database, disc file On-page connector, inside the symbol we put a number or a letter Off-page connector, inside the symbol we put a number or a letter

Software support of process analyses  complexity of applications used to analyze processes:  simple graphics functions built into word processors, spreadsheets and presentation editors  dedicated tools for creating diagrams (eg. FlowCharter, Visio, SmartDraw)  tools used to analyze the completeness, clarity, results, execution time and workload, and then simulate actions to improve processes (eg. iGrafx ARIS)  advanced tools allow you to generate the specification and software structures for applications  in order to analyse processes we often use standard UML (Unified Modeling Language, or Unified Modelling Language), a formal language used for describing the world of objects in object-oriented analysis and object-oriented programming

UML – graphical symbols Case: applied in use case Actor: applied in e.g. use case and activity diagrams Initial state: applied in activity and state diagrams Final state: applied in activity and state diagrams Action: applied in activity diagrams Decision point: applied in activity and state diagrams State: applied in state diagrams Object: applied in interaction diagrams Communication: applied in interaction diagrams Communication causing the tranfer of value to the object causing action Class: used in class diagrams

UML - 12 types of diagrams in the design of information systems 1.Use case diagram 2.Activity diagram 3.State diagram 4.Sequence diagram 5.Collaboration diagram 6.Class diagram 7.Object diagram 8.Component diagram 9.Composite structure diagram 10. Interaction overview diagram 11.Timing diagram 12. Deployment diagram system dynamics modeling

Use case diagram  use case diagram - describes the use cases of the system (application), the actors and the relationships between them. It is applied for determining and modeling system activities  use cases are applied to define sets of activity sequences. Each of these sets represents actors’ interactions with the system  the term "actor" is a general term and identifies any participant in the process. Actors perform specific activities connected to the realization of equipment rental services  use cases are applied at the stage of identifying the requirements and analysis for presenting, specifying, creating and documenting the expected system actions

Activity diagram  activity diagram is a diagram where we distinguish mainly the activities carried out with time  in the simplest activity diagram we distinguish: initial state and, if applicable, the final state, and the states of activities and transitions  activity diagram is a model illustrating the sequence (succession) of activities  activity flows are used for presenting, specifying, creating and documenting the processes taking place in an enterprise

State diagram  state diagram - shows the dynamic aspects of the system, such as the impact of the sequence of events on the behavior of various objects  it is important in order to analyze the consequences and circumstances of individual actions.  presenting them in the sequence in which they appear we can observe the sequence of events. At the same time we see the "state" of various distinguished objects  which objects we distinguish which conditions of these objects we want to register, stems from the observation of the details of the problem

Sequence diagram  sequence diagram shows the sequence of communications in time  we mainly present objects and communications on sequence diagrams  it allows to observe the order in which individual activities take place in objects. At the same time, this type of diagram allows to denote objects in the process  object is a default information category describing a person, thing, event, idea; It is "the full realization of abstraction," which is a class  sequence diagram emphasizes the sequence of communications in time (time runs down diagram) - the lower the communication is placed on the diagram, the later it occurs in the activities. The transfer of the communications results in the action of the object, indicated by the arrow

Collaboration diagram  collaboration diagram - shows a collection of objects, the connections between them as well as communications. Thus, it contains the same elements as sequence diagram, but it differs from it as it emphasizes "the organization of objects participating in the interaction." On the diagram there are collaboration paths; we also take into account the sequence of communications  it allows for presenting the functionality of the computer system which will be created for the company  we see the objects and their relationships resulting from the transmitted communications (lines/ communication arrows)

Class diagram  class diagrams - are used to model the interdependencies between classes, they can also be used to model the logical database diagram  in the case of conventional methods of database design the emphasis is placed only on the data, while for class diagrams we can also model activity, which is useful in process modeling

Computer software

Program - definition  program - a set of instructions that control the computer operations, designed to carry out a specific task.  computer software is designed in the programming process by developers on the basis of indicated specifications. Software as a manifestation of creativity is protected by copyright, and their creators allow its use under the conditions defined in the license.  We distinguish two forms of software:  source, which is formed during programming and allows you to modify and expand the program,  executable (i.e. the machine code), which is used to carry out computer operations, and the output is visible to the user in the form of printouts, images on the monitor, changes in the data, etc.

Source code vs machine code  source code - it is the content of a computer program written in a programming language, usually as a text in human-readable form using an appropriate programming environment. In such a form, the program is understandable for a man (programmer familiar with the programming language), however, cannot be directly used and executed by the computer  software languages are artificial languages designed to clearly and directly forward commands to the computer  the source code is converted into machine code understandable for the computer (CPU) by the translator (compiler), or is analyzed and executed by a special program called an interpreter  machine code, which is designed for a specific type of processor cannot be executed by processors of another kind

Programming process - basics  defining the problem (task)  designing software structure and specifications  coding software modules  verification and validation of software

Defining a problem  definition of the problem - in most cases it is a detailed definition of the requirements that are placed before the final computer program by its future users  in this phase we should, if possible, create a complete list of specifications and users' expectations regarding the functioning of the program, or the entire computer system  identification of the requirements may be conducted with the use of different methods and techniques, the most popular of which include interviews, surveys, observations and documentation analysis  the development of the collected material and its presentation in the form of specifications is comprehensible for users as well as designers and developers; it is the task of system analysts to formalize the description of reality analyzed using appropriate algorithms

Designing software structure and specification Designing software structure and specification - is the process of mapping functional elements present in the requirements specification for programmatic elements adapted to the realization possibilities of the developers Designing covers such issues as the input and output of data, creation of data structures and, above all, it should lead to breaking down the tasks into smaller programming elements (i.e. the functional decomposition ), which can be expressed by means of simple algorithms, supplemented with the description of auxiliary operations Designing of software structure can be carried out by means of a structured or object-oriented approach In the structural approach we distinguish two methods:  bottom-up design - the realization of the principle of 'from specific to general’: at the beginning we define a set of elementary tasks necessary to realize the main problem (e.g. data entry), by means of which we build larger structures which deal with processing of extended fragments of the task - the structures become even more general, until finally we come to the main diagram which manages individual modules  top-down design – at the beginning of the process we generally formulate the task, the task formulation is then analyzed and broken down into interacting parts, and they are further divided until we reach the stage of elementary fragments, the programming of which is relatively easy  object-oriented approach - is a shared responsibility for the execution of certain tasks between objects - structures having an identity, state (fields) and behavior (methods) - that are representations of objects derived from the real world

Coding software modules  coding software modules – programming of software implementing the modules specified in the draft structure of the software  if we have an appropriate detailed design, the coding function is basically a mechanical action, because virtually all mental work devoted to the solution of the task focuses on the previous stages  programming (coding) is only the act where we record the specifications in an appropriate programming language

Software verification and validation  software verification - a test of whether the software is being developed correctly, or if the software performs a specific function correctly and whether it is compatible with the specifications  software validation – a test of whether you are designing a program which is in line with customer expectations  software testing - one of the basic procedures used during verification and validation, its purpose is to detect and remove bugs and assessment of the software reliability  in the testing process we design a plan ( testing scenario ), where we need to observe appropriate rules, e.g. the rule that the person (or persons) who develops and conducts testing should be independent, not one of designers and developers involved in the project, more emphasis should be put on testing typical (normal) situations rather than exceptional ones, in the case of complex systems we should test software compatibility, and the evaluation of the reliability of the program should be carried out on both on test and real data

Integrated software development environment  Integrated Development Environment (IDE) - a set of interconnected applications used for creating, modifying, testing and maintenance of software that allow you to:  edit the source code  compile source code  create program resources (forms, screens, dialogs, menus, reports, graphics)  create databases  create software components, etc.  Rapid Application Development (RAD) - a technology solution within the framework of the IDE which provides the programmer with the ability to maximize prototyping (creating early software version which contain only the essential elements) and the use of a large set of ready-made components (predefined elements for ensuring e.g. access to databases which they do not need to create from scratch); examples of RAD environment are Delphi and Visual Basic

Version management  version control system - helps to save and store the source code of a software project with their history of changes  repository - place which allows to place program source files that can be accessed and modified by many programmers; it is often placed on a remote server; the repository should contain the most recent versions of sources, so that developers have access to the latest version and can work on it, and all the changes are implemented in an automatically updated repository

Software engineering  software engineering - (the 60’s) deals with aspects of software development: from analysis and definition of requirements, through design and implementation, to the evolution of packaged software  according to this approach, the software should be treated as a product to meet the specific technical, economic and social needs of users

Computer software - main events 1931Kurt Gödel, publishes an incompleteness theorem, which is sometimes referred to as the basic theorem of theoretical computer science 1937Alan Turing defines an algorithmic machine 1945John von Neumann describes the architecture of a machine with a separate recorded program. A year later John von Neumann designs EDVAC (Electronic Discrete Variable Computer) 1954John Backus together with IBM team implement FORTRAN – the first high-level programming language which gains in new popularity 1958Other popular programming languages: ALGOL and COBOL emerge 1964John Kemeny and Thomas Kurtz present BASIC (Beginner’s All-Purpose Symbolic Instruction Code) 1970Dennis Ritchie and Kenneth Thomson design Unix operating system in Bell Labs 1971A new relational database model is designed by Edgar Codd, an employee of IBM 1974C programming language is designed 1975Bill Gates and Paul Allen establish Micro-Soft company in New Mexico (USA), later the name is changed to Microsoft 1979The first VisiCalc spreadsheet is designed for Apple microcomputers 1981IBM starts selling first PCs with MS-DOS 1.0 operating system 1984Windows 1.0 is designed by Microsoft for DOS operating system, which uses a graphical user interface (GUI) 1987Microsoft introduces Excel to the market 1995Sun develops Java programming language ….

User interface  user interface - part of the program, which is responsible for communication with the user, taking his orders and responding to them by displaying appropriate screens; may be in the form of text or graphics  text user interface - the screen constructed with alphanumeric characters and a limited set of semigraphic symbols; an example of using this kind of interface is called command line interface, which is based on special commands entered by the user  GUI (Graphical User's Interface) - allows the user to select appropriate buttons on the screen using the mouse; thanks to such an approach the ergonomics of the software increases significantly. Working with the graphical user interface is usually quicker and certainly a lot easier for less experienced users, than working with text-based interface

Characteristics of computer software  from the perspective of the classical software distribution, taking into account the features of the program and costs factors, software can be divided into two main groups:  system software  application software

Podział rodzajowy oprogramowania komputerowego Oprogramowanie Oprogramowanie systemowe Systemy operacyjne Programy pomocnicze Systemy programowania Oprogramowanie użytkowe Programy narzędziowe Edytory tekstu Programy analityczno- statystyczne Arkusze kalkulacyjne Programy wspomagające pracę biurową Systemy zarządzania bazami danych Programy komunikacyjne Programy graficzne Programy do pracy grupowej Systemy użytkowe Systemy powielarne Systemy indywidualne Software System software Utility software Operating systems Helpers Programming systems Utilities Utility systems Text editors Spreadsheets Analytical and statistical programs Standard systems Tailor-made systems Programs supporting office work Communications programs Database management systems Graphics program Programs for the group work

System software  system software - a group of programs which do not directly assist the user in accomplishing his tasks, but enable, facilitate or organize the work of the computer system. The system software includes:  operating systems - needed to start the computer system and properly operate it; they supervise the work of all running programs and computer equipment  support software - extends and enhances the functionality provided by the operating system  programming systems

Operating system  basic tasks:  hardware resource management (optimizing the use of devices within the computer system, and controlling them)  management of file archives (file system support, i.e. logically ordered structure data stored in external memory, e.g. hard disk)  designing and providing users with applications (allocating CPU, memory, etc. to utility programs)  elements of the operating system:  command interpreter (operating system shell - its task is to allow communication between the user and the machine; modern interpreters perform this task using a graphical user interface  kernel - the inner part of the operating system, which contains the basic functionality required in a particular installation. The kernel includes file manager, device driver and a memory manager

Operating system: main features  multitasking - the possibility of running more than one program at the same time; this allows simultaneous work with various applications, e.g. a word processor and spreadsheet; you can also instruct your computer to do some of the more time-consuming tasks to be performed "in the background"  multiple access - the possibility of simultaneous operation of multiple users of a single computer system. This requires the existence of a network, where the central computer (server) is connected to the terminals of the network (terminals), or PC computers,  data protection - a group of such properties of the operating system, which ensure its stability (resistance to hardware failures and software bugs), and authorize access to data (restricting users' access to resources of a computer system according to the principles adopted in the organization)

Auxiliary programs  They extend and enhance the functionality provided by the operating system; they are not used directly to carry out the user tasks, but support the work of other programs  Auxiliary programs are divided into 5 groups:  middleware - programs that considerably facilitate the use of the basic functions of the operating system  diagnostic, test and repair programs - used to analyse the components of a computer system in order to determine their performance or detect potential faults in the configuration or malfunction  antivirus programs and firewalls - used to detect and destroy viruses and Trojans and to prevent external attacks on operations carried out on a computer connected to the network  Packers? – used to compress files and combine them into larger collections, called archives; they are used primarily to store backups of your data and programs  web browsers - software for viewing web pages

Programming systems  They are used to create computer software  They usually consist of two elements:  programming language, which is a greatly reduced natural language and has a strict syntax  the language compiler - a program that translates the code understandable for the programmer into machine code, understandable for a computer microprocessor  low-level language - the type of programming language, which to a limited degree disregards the design of the central processing unit (shows a strong resemblance to machine code)  top-level language - the type of programming language whose syntax and keywords can greatly facilitate the understanding of the program code to humans, thereby increasing the level of abstraction and distancing themselves from hardware nuances

Generations of programmming languages  I generation – machine code, i.e. a string of zeros and ones which representts the binary record microprocessor together with its parameters. Machine code is characterised by the fact that it can be „understood” and exectuted by the microprocessor of the computer; however, it is not clear for the programmer  II generation - languages caalled assemblers whose microprocessor functions are codified by means of the so-called mnemonics. They are short and simple commands, which are exact equivalents of the procedures, which may be performer by the procesor; they are applied mainly to create the elements of the system software where speed and optimal use of hardware functionalities are of primary importance  III generation – the largest and the most common group of languages; they offer such features as proceduralność, or the opportunity of single programming of complex procedures, and subsequently – repeatedly referring to tchem in the programme  IV generation (Fourth Generation Language - 4GL) – top-level languages; they enable us to concentrate on merit. The programming system controls technological aspects of application operations using standard, proven solutions. They provide a possibility to quickly develop software with a rather inflexible programming language, thereby limiting the scope of application. They are commonly used to form the utility systems which show a considerable degree of similarity of the solutions.

Utility software  performs certain user tasks ; assists users in both simple task, such as writing texts or taking notes, as well as in complex processes of business management or in solving complex numerical problems  application software is divided into two groups:  utilities (they are used to operating on sets of data of specific format)  utility systems (software implementation of enterprise management information systems)

Software tools  the group of tools includes:  editors (word processors) used for creating and editing text documents  spreadsheets supporting the processing of large data sets organized in the form of a table  database management systems used to create and perform operations on structured data sets  graphics packages which are used for creating, processing and presentation graphics; they are divided into packets for graphical presentation of numerical data, graphics packages which help you create charts and diagrams, packages for dynamic presentation  analytical and statistical programs which support analysts, including in the financial sphere  desktop programs which facilitate the organizations of common activities, PIM programs  communicators which enable communication in the form of text, voice and video  groupware software which support teams work employees, they focus on achieving a defined objective  the modern utilities operate in WYSIWYG (What You See Is What You Get) - the user sees the contents mapped on the screen in such a manner in which it obtains in the form of a final (print, HTML page)

Tools  a group of software tools includes: finance and accounting, distribution, sales management, warehouse management, production control, payroll, project management, customer relationship management systems, etc.  at present we deal with integrated management support systems which allow you to meet the information needs of most enterprises  with regard to the possibility of systems application in many enterprises we distinguish two groups  standard systems  individual systems

Standard systems vs. Individual systems  Standard systems - they can be used in different business entities frequently with different functional requirements; the condition of standardization is high flexibility and the possibility of a wide system parameterization  the majority of software tools on the market are the standard systems, they are sometimes referred to as "off the shelf" systems, especially in the case of software for smaller business entities (e.g. invoicing systems). Such solutions are characterized by rapid and simple implementation process for the operation and a relatively small price, but we should bear in mind that these systems have a number of limitations, which often result in a modification and expansion, which also entails additional costs  Individual (dedicated, tailor-made) systems are created to meet the requirements of a particular business object. Due to its specialization and unique solutions usually they cannot be used in other business objects  these systems are made to order (commissioned by mostly medium-sized and large companies or institutions) in the absence of an appropriate solution on the market. This involves the necessity of carrying out the entire procedure of software development, it is usually more expensive than buying the standard system

The principles of software ergonomics by J. Nielsen and R.Molich  Visibility of the system status. The system should always keep users informed about what is going on, through appropriate feedback (confirmation and messages)  Match between the system and the real world. The system should speak the user’s language using understandable analogies drawn from reality  Give the user full control. Users often choose system functions by mistake and should therefore be provided with "emergency exit", using the "undo" and "redo"  Consistency and standards. Use the same words, symbols, situations and actions should be applied in a uniform manner throughout the product, in accordance with the principles adopted for the environment, platform or operating system  Error prevention. Preventing errors using a carefully designed dialogue with the user is less time consuming than designing sophisticated error handling system  Recognition rather than recall. User actions should be the result of selection from the list, rather than recalling from memory; all information and instructions you need in a given situation should be constantly visible on the screen, so as not to burden the user memory  Flexibility and efficiency of use. Users should be able to adjust the way of carrying out common tasks and access "shortcuts" to the functions you need  Aesthetics and minimalist design. Creative layout increases clarity, reducing eye strain and facilitates information search  Provide efficient error handling. Error messages should be expressed in plain language and should indicate the type of problem and its solution  Help and documentation. If the system is provided with the documentation, should allow fast location of desired information, and the instruction on how to solve problems should be concise and relevant to user tasks

Technologies of collecting and presenting data

Input and output technologies  input technologies – their task is to collect data in memory or external computer memory in a digital form, allowing processing.  output technologies - issue processing results in the form requested by the user of the system  both technologies use two basic methods of input and output data :  intermediate  direct

Input methods  Indirect method of data entry - involves the use of secondary storage media such as magnetic tape, diskette, CD, memory stick, which are not directly readable to humans.  data stored on the traditional media (the source document) are transferred to one of the carriers by means of recorders (or computer in the case of data storage device), then the data is read by appropriate devices and entered into the computer memory  Direct method of data entry - is based on capturing source data on documents readable for both a man and for specialized computing devices, enabling automatic reading of data,  especially prepared and completed documents are both the source document and storage medium. With this method we commonly use keyboards connected to a computer's central processing unit, handwriting scanners, touch screens or various kinds of automatic data recorders (digital / electronic scales, voice recorders, etc.).

Output methods  Indirect method of data output allows you to obtain the results of the processing on all information which are unreadable directly to the user. The resulting data are stored on these media by suitable devices (e.g. photos or digital movies, music).  this method is used when the processing results are input data into the next processing cycle or to save the time of the computer system work, e.g. if the print results will be obtained outside the system  Direct method of data output consists of entering data on a user- readable storage medium where we can present the results in the form of characters (alphabetic, digits and special characters), or drawings (diagrams, charts, photos)  carriers are mostly paper, foil, screen monitor. The resulting data are recorded on paper by printing devices (printers) or drawing devices (plotters)

Realizacja zadania w systemie informatycznym TASK REALISATION Source document Non-formalised information Data base Import of data in electronic form Printout Display on the screen Data base Export of data in electronic form INPUT OUTPUT

Input and output data  The input data (the most common forms are source documents) have fixed values such as:  scope of data  form (formalized data)  the procedure for completion (what data can be / have to type in the appropriate boxes)  the formal conditions confirming the correctness of data  the procedure for circulation within the company (business entity)  The output data (they usually take the form of prints or combinations of text and/or tabular) must have:  established scope of data (selected by some criteria, e.g. data, period of time, level of detail)  form (formalized data)  ordering (the order of data to be printed)  summary data (subtotals and general)  purpose (the procedure used in the company / business entity)

The form of input and output data  on-screen form factor and lists created on printers and plotters, stored in storage devices or displayed on monitors

Input form  a document which contains certain data that is already pre-defined (non- changeable), as well as empty boxes that the user completes with data (according to data formats designed for the system and accepted procedures)  we mainly deal with entering data using the computer keyboard or scanning documents using appropriate hardware and software. Other methods of entering data are technologies using magnetic card and barcode readers as well as smart cards.  design of input forms include the following operations:  choice of input methods  planning the arrangement and layout of data on the screens (windows)  selecting data to be examined and designing control procedures

Designing of input forms I  entering data - is conducted by the method of dialogue or command language (command line):  most common method of dialogue is filling out forms. This method consists of entering data in highlighted and listed places on the form, which appears on the screen. The form on the screen should be designed taking into account the principles of document design, to facilitate its completion. Another method is the introduction of interactive dialogue consisting in introducing user-specific data upon receipt of your questions concerning their values (or command concerning the input of specific information). After by the computer specific information followed by another question (command etc.)  layout of the screens is to design the input fields on each screen and their mutual arrangement. Designing fields is based on specific project data structures (e.g. the field type and its characteristics), but it should also include activities such as:  locating individual fields on the screen  determining the spacing between the fields and separators inside the boxes  determining how to distinguish fields (color, brightness, flicker, backlight)  determining the allocation of the fields protected (read-only) and unprotected (filled in by the user)  displaying or not displaying (e.g. password masked with asterisks)

Designing of input forms II  designing of control processes of input data - checking the information applies to both documents (external audit), as well as the process of transferring data from documents on machine data carriers, or input data directly from the keyboard. In the process of data input directly from the keyboard (or the less and less common process of moving data from source documents on machine data carriers), there is the greatest danger of making mistakes  organization of control correctness of the data is transmitted to the designation of fields from the document, in relation to which we will check:  type of field and the number of characters,  the range of values (less than, equal to, greater than the remembered values or those falling within a specified range)  list of values (the value of the field must correspond to that one of the items stored list)  control digits  with regard to the data logically associated with each other we must also inspect these links

Output form  output form (summary, report ) - passive document that contains the data previously defined, generated spontaneously by the system according to the algorithm  the system is evaluated by the user on the basis of the processing results. The core evaluation criteria are the scope of the system, layout, clarity and usefulness in the management process ; They should be taken into account when designing output forms  design includes system output (for outputting the results on the monitor screen):  design of output forms  process design data control output

Designing output forms I  designing a system for ranking the resulting data, we should observe the following rules:  the resulting summary should contain a complete set of data on a particular issue in the appropriate section and in sufficient detail  data system should be clear and easy to understand (logical sequence of data, explanations of abbreviations and symbols used)  each statement should be provided with a header (a uniform structure for the system), including the name and symbol of the statement, possibly as a user name, date of execution and page number  in relation to printed statements we must also specify:  recipient  frequency of emissions  number of copies

Designing output forms II  control of output data includes checking:  compliance with the layout of the data arrangement on the project design and its completeness  statements readability (clarity)  correctness of the results (of their compliance with those produced by conventional methods, historical values, checksums, etc.)  output information can take many forms and may be presented on a variety of media. Output formats can be:  tables - presentation of alphanumeric information in the form of columns and rows  The zone system - putting data in different places printout or screen form  charts and other graphic or multimedia presentations  Standard text descriptions (narrative form)

Converting paper source documents into electronic documents  document scanning - a process in which the documents are converted to electronic form by means of the scanner  Optical Character Recognition (OCR) - the process by which scanned documents (bitmaps) are analyzed and converted into text, allowing further processing  Intelligent Character Recognition (ICR),a variety of OCR, which uses sophisticated lexical tools. ICR technology is typically used when converting handwritten materials into text form

Electronic Data Interchange (EDI)  EDI - data exchange formats described by means of international standards between IT systems of trading partners, which takes place without or with minimal human intervention  the main features of EDI:  it enables the elimination or significant reduction of paper documents and, as a consequence, it eliminates the tedious work consisting in their creation, copying and transmission  it allows the immediate transmission of information which is contained in typical commercial documents  it operates independently of the type of enterprise software applied  currently the most popular EDI standards are ANSI X12 and UN / EDIFACT (Electronic Data Interchange For Administration, Commerce and Transport); at present all the organizations responsible for standardization of EDI, decided to migrate to EDIFACT standard  currently EDI document format is described by means of XML language

EDIFACT – communications and documents EDIFACT communications can be divided into three groups:  commercial communications (catalogue pricing, ordering, invoice), allowing for the exchange of information between the seller and the buyer  transport communications (transport order, delivery note) used to organize the delivery of goods  financial communications (transfer, information about transactions) used to make payments and report on operations EDIFACT documents are divided into:  basic data containing information about companies and products – they are exchanged between trading partners, other messages sent between partners refer to them  transactions describing business processes between cooperating companies – they start with the goods or services order, including communications necessary for the transport of goods and they are completed with issuing the transaction invoice and payment order for the goods or services  reports and planning - the documents are used to inform partners about the current situation on the availability of goods and to facilitate effective planning and supply chain management

Identification of the object in the supply chain  identification - the unequivocal identification of the object (the object)  by a man ( manual detection )  by appropriate electronic device, which does not require human intervention ( automatic identification )  as a result of a combination of these techniques, i.e. human senses and automatic sensors ( semi-automatic identification ); the most common solution  the identification? system includes:  a device capable of identifying the object with the appropriate sensor and an electronic control system which allows eliciting information from the object  object with a set of features that allow its identification - the object is stored in a coded manner, information concerning the object allowing its identification and possibly additional information ??

Classifiation of identification systems Contact systems Contactless systems Identification systems Semi-automatic Automatic Mechanical Magnetic cards: - bank - telephone Electronic Smart cards: - bank - telephone RF and Magnetic Transponders: - GSM i GPS - RFID Optical Barcodes: --dimensional - two-dimensional - complex

Semi-automatic identification systems  an individual in semi-automatic systems enables reading of the information from the object which is identified by means of the identification device, e.g. by inserting the card into the reader or proper positioning of the product to make it possible to read the information in the bar code by an appropriate scanner  contact, semi-automatic systems - there must be a physical contact between the object and the sensor of the device; the disadvantage is a long time of reading the information; it is used when it is essential to provide for the security of transmitted information  contactless, semi-automatic systems - much faster and more convenient in use than semi-automatic contact systems

Barcodes  barcodes - the most popular identification system using optical systems  the first barcode standard called UPC (Universal Product Code) - Standard Product Code was developed in the United States in the early 70s of the twentieth century  since 2005, GS1 Global Identification System has been in common use  advantages of barcodes:  low price of printing bar code labels, especially when the bar code is printed on the packaging along with the design of their packages  short time of reading the labels by means of the scanner and sending the information to a computer - significantly faster than entering a product number by an operator  high efficiency of reading the bar code and the signal of proper identification of the product (visual or, most frequently, sound signal)

Barcodes – division criteria Types of codes  one-dimensional (linear, 1D) code - the information is presented in one line  two-dimensional parallel code – represented by a number of lines of the code  two-dimensional matrix code - recording does not use lines, but other symbols  complex codes - made up of one and two-dimensional codes  three-dimensional codes Type of coded symbols  numeric – consisting of digits in the decimal system  alphanumeric - digits and other ASCII characters, sometimes the characters of some alphabets  The number of encoded characters  codes with a restricted number of encoded characters (fixed length)  codes with different numbers of coded characters (variable length) The method for verifying the reading of the data  Self-checking codes - where some error-checking procedures are implemented in the construction code  codes with the control character (e.g. with the number or checksum)  self-checking codes with

Automatic identification systems  they do not require human participation in the identification process enabling a complete automation of the process  based on the transmission of radio waves, the objects need not be in direct optical contact  the American GPS system was the first popular system that allows automatic location of objects automatic identification  the systems are widely used by forwarding companies to locate objects (e.g. lorries)

RFID (Radio Frequency Identification)  objects equipped with special tags (transponders) are identified by means of them when they are in the proximity of an appropriate scanner  transponder (micro radio transmitter) is made up of an antenna and a miniature integrated circuit, where you can save the information; RFID tags are divided into:  active (with their own power supply)  passive (without their own power supply), are powered by the induction of energy from radio wave transmitter

RFID – operation model Internet network MiddleWare database RFID reader Energy Signal Transponder s

GS1 and EPC identification standards The GS1 System  it includes standards for identification of retail and wholesale materials, logical units, physical locations, resources and services  this cross-sectoral and international system of unambiguous and automatic identification and electronic data interchange used in industry, trade, services and administration  It is common to Europe, Canada and the USA and many other countries EPC (Electronic Product Code) standard  is the equivalent of GS1 standards for RFID technology  the information identifying the product is contained in the RFID tag and the full description of the product is available in dedicated databases available in the Internet Compatibility of GS1 and EPC  product information is stored in a common database so that both standards enable the identification of the same product  they may be used interchangeably or simultaneously resulting in the same functionality

Visualization of economic information  graphic presentation of complex data structures to facilitate obtaining the information needed by the recipient of the information to make choices and/or decisions  design of the visualization of information should include:  task (which it facilitates)  recipient (satisfying his/her information needs, their knowledge and experience in the reception of a specific graphic image)  the type of data (discrete or continuous, quantitative and qualitative data, nominal and ordinal data etc. the presented volumes, i.e. the minimum and maximum values, and the dynamics of their changes, knowledge of the range of data, as well as whether there are data which should be distinguished)  properties of particular graphical methods  time (for the recipient to become acquainted with the information)

Categories of graphic images 1  Tables contain orderly arranged system of words, numbers, characters, or a combination thereof; They represent a set of facts or combinations in a compact format  they should be used when there is a lot of data, where another graphic form could be unreadable and difficult to understand or would have the inappropriate size  types of tables: numerical, graphic  numerical - contain only figures; useful when you need to search and analyze precise figures  graphic - including graphics, which does not exclude, however, the numerical values  Charts are used to present numeric data by means of graphic elements  they are used to present trends and comparisons  types of charts: surface, donut, line, bar charts, scatter plots

Categories of graphic images 2 - types of schemes  Charts - (often associated with diagrams) presenting the timing and/or spatial relations between various actions; They are used to display physical or conceptual dependency, rather than numerical quantities; We distinguish the following schemes:  organization (organigram) - is used to document or planning for structural and functional relationships of organizational units within the enterprise  circular - allows you to show objects and relationships existing between the two with circles and lines  pyramid chart - used to illustrate the hierarchical list, the highest point in the pyramid represents usually the most important or highest level  network - is used to indicate relations by means of a line connecting all elements arranged on the diagram; additional use of different colours or types of lines makes it possible to signal what kind of dependence exists between them  flow - shows how a particular process or procedure works in given time  time - used to illustrate the start, finish and duration of individual tasks  cascade – presents subsequent steps of the process with appropriate graphic symbols

Categories of graphic images 3  Maps - used to describe the location of the basic terrain by means of symbols, or by placing individual letters (e.g. marine, road, topographical maps) and to provide linkages between the size and the degree of dispersion of given phenomena in the area or the intensity of its actual occurrence; Maps show the statistics of the phenomena in the geographical area and allow to show local dependencies; other tabular forms or other forms of visualization do not provide such possibilities of presenting information  Icons – they show miniature images of objects, actions or concepts, easy to understand by the recipient. They can also be presented as a symbol of a totally arbitrary appearance, where the recipient must be able to interpret their meaning. They are used when:  the recipient must act quickly and reliably (a well-designed icon can be faster to interpret than the same information conveyed by other labels)  we need to overcome the language barrier  you need to quickly recall and associate specific information (a lot of people remember what they saw better – e.g. the faces, than what they heard – e.g. name)  there is a need for direct detection and identification of a large collection of items, for example: basic concepts, meanings and products (it is easier to find a distinctive graphic image in a given set than to find a specific word in the string of the same characters)  has a limited space (powerful icon may convey more meanings than a label)  Drawings - used to represent the actual image of the product or present the possibility of such a device or tool.  Photos - used for the same purposes as drawings, photographs, however, they reflect the realism and precision in a better way, because they themselves are "current" images; They are actual images of the object or place.

Graphic presentation software  typical graphic programs  for creating charts and diagrams  for image processing  for design  for advanced editing of images and three-dimensional animation  toolkits with graphics functionalities  spreadsheets  analytical and statistical programs  information systems containing complex modules for data visualization  geographic information systems (e.g. http://trendsmap.com)  decision support systems  systems for automation of production processes

Multimedia technology  multimedia - computer enables integration and control of the implementation of individual components  Media in the sense of information technology - an integrated hardware and software environment enabling simultaneous input, processing and presentation of various forms of data (text, audio, video, etc.)  characteristics of the media are:  a variety of information and a possibility of its parallel presentation (parallel existence of different media)  interactivity - a feature observed in systems with multimedia solutions  multimedia technology – a system comprising hardware and software environment allowing the user to input, process, and present a variety of data format, where we need at least two different channels of human perception

Elements of multimedia technology  IT equipment – is the basis of any multimedia system and determines its capabilities; It allows for the collection, processing, storage and presentation of multimedia data  software - determines the content, which the user receives by means of equipment; the program is the multimedia program if it allows the user for parallel perception of various media (application which presents media sequentially is not a multimedia application); We distinguish the following categories of software:  multimedia operating system - is an extension of the classic operating system with the functionality of management of devices and files, typical for multimedia data  multimedia software tools - used to create and use multimedia applications, they include among others: hypertext tools, generators of multimedia applications, multimedia databases, programming languages  multimedia applications - they are multimedia programs created for specific areas  each multimedia application may be either:  passive (there is a multiplicity of forms of stored data and the possibility of their parallel presentation)  interactive (application is additionally enriched with features of dynamic control mechanisms of searching databases containing different types of data and mechanisms of simultaneous presentation of the data, with the result that the user can customize multimedia presentations to suit your needs)

Technologies of data storage and processing

Management of electronic documents  document management technologies - technologies for automating of the document life cycle within a company, including the creation of the document, its transmission, processing and storage (realization by SZDE)  electronic document management systems (SZDE) - a set of measures that (wholly or partially) automate the software-hardware documents life cycle in an organization (SZDE is part of ECMS)  systems for enterprise content management (Enterprise Content Management Systems - ECMS) - their task is to obtain, manage, store, archive and transfer information and documents accessed through the corporate portal

Document life cycle Archivin g Preparation Reviewing Search and subsequent use Use Approving Distribution

SZDE (Electronic Document Management System) – technology application  Controlling the circulation of documents - technology which allows to define, start and track the route of a document within the organization; Specific tasks:  defining the key points of the document circulation  determining the document's author  versioning  distribution  commenting  reviewing  approving and / or rejecting the document  Archiving (storage) documents - allows you to save their content and attributes of data on durable media (tape, disk arrays, optical technologies)

Standard format of electronic documents  XML (eXtensible Markup Language) document - currently the most widely used standard for formatting and describing the electronic document  XML language  universal formal language designed to represent various data in a structured way  independent of the hardware and software platform, which enables the easy exchange of documents between different systems  describes the data (meta-language) - there is no limit on the number of tags, it allows you to store any data in the manner which is most convenient for the user (users can specify a data structure that can be tabled or that may be presented in the form of a tree)

Electronic Data Management System (SZDE) functions  main (basic) functions of EDMS (SZDE)  extracting a document storage area (a central repository of documents)  adding documents to the storage area and identifying  search for documents in the storage area  supplementary (additional) functions of EDMS (SZDE)  blocking and unblocking access to documents (check-in, check-out), which ensures that only one user at a time can modify the document  version management (versioning) of documents, or monitoring changes in a document  creating the organizational structure of documents, i.e grouping and categorizing documents  defining routes and sending documents to particular users  converting paper documents into electronic documents (imaging)  archiving of documents on various media  securing access to documents

The benefits of automation of the process of entering and processing documents  faster access to a document,  taking into account user rights to enter and view documents in the system,  viewing all events related to the document,  no need to describe documents manually  easy search of documents by various criteria,  simultaneous access to documents by multiple users and for multiple locations

Data bases in transactional systems  Database - a set of interrelated data stored in a specific way in the structures corresponding to the assumed data model  The data model - a set of general rules for the description and use of data in the database  Database management system (DBMS) (database management system DBMS) - universal software that enables definition, construction, manipulation and sharing of databases to applications and users  Database functions:  data collection  data update  data sharing  ensuring data security and rights to access the data  management of user information privileges

Databases according to data model  hierarchical  network  relational  object-oriented  object-relational  stream  temporal

Hierarchical model of data  tree structure, which was adopted grouping of data in the form of successive levels  it is a parent-child model, where we distinguish parent tables and descendants.  each child table (descendant) can be associated with only one parent table (parent).  parent each table can have multiple child tables - basic relationship in this model is the relationship one-to-many (1: N)  currently a hierarchical model is used to store geographical data and file system support

Network data model  It is a development of a hierarchical model in such a way that the child tables may be related to more than one parent table.  The model uses a many-to-many relations (m: n), introducing an additional type of collection (set).  Specification of the type of set consists in providing the type of record owner and elements of the set (members) and possibly also a key of organizing elements.  This model solved the problem of data redundancy by representing the relations in terms of sets rather than hierarchy

Relational data model  The relational model which represents the database as a set of relationships was defined by E.F. Codd in the 70s.  Database operations are carried out by operators of relational algebra, enabling the user to create, query, and modify data while maintaining integrational restrictions, implicitly or explicitly defining the limits of data  The fundamental data structure is the relationship, which is a subset of the Cartesian product in selected areas. The relationship consists of a finite set of tuples or rows of identical structure but with different values.  Every relationship can have explicitly specified integrational limits, which as rules guarantee that the data in the relation comply with this rule. They can be defined for a single attribute or for the entire relationship of the following form:  primary key,  foreign key,  unique,  null, not null,  check.

Object-oriented data model  based on object-oriented programming languages, using hierarchically defined objects that can be linked into a network through the semantic relationships between objects  relational data models show certain limitations in the design and creation of complex applications for the needs of software engineering, Computer- Aided Design (CAD), Computer-Aided Manufacturing (CAM) and Computer-Integrated Manufacturing (CIM ).  in these areas, as well as in telecommunications, geographic information systems and multimedia, object-oriented databases are able to process data structure with a high degree of complexity efficiently. Object-oriented approach to these applications allows you to specify both the structure of complex objects and operations that can be performed on those objects

Object-relational data model  Object-relational model was created in response to the adversative possibilities of relational and object-oriented database model.  The possibilities of object-oriented scheme are contained in relational databases, but not vice versa. One of the most important differences in the design of object-oriented and relational databases is different treatment of relations  In the object-oriented model relations are generally represented by semantic relations and object identifiers (OID). OIDs can be declared in one or both directions, depending on the intended mode of accessing the objects.  In a relational database, relationships between tuples are defined by the fields (i.e. primary and foreign keys) identifying interrelated tuples. Limiting fields to single values results from the fact that in the relational model tuples field cannot store multiple values.  An important feature of which differentiates a object-oriented database from a relational database is the heredity. In object-oriented databases heredity is defined by class-of relation, while in object-relational models additionally through functions that allow a direct link between these structures and through the operations of abstract data types.  Current object-relational database management systems (ORDBMS) allow to describe data in multiple formats, m.in.:  formatted or unformatted text allowing for syntactic analysis of documents  graphics - drawings and illustrations as CGM, pict and postscript standard.  the stored images in bmp, jpeg,  video recorded in the MPEG standard coding audio-visual information,  structural sound (music, tones) and data samples stored in wav, mp3.

Stream data model  Real-time databases operate on massive streams of data, and are generally associated with a stock market expert systems.  In the field of databases they are referred to as streaming databases due to the source and method of preparation of the data.  There are many database applications where data is available in the form of a stream; however, the access to past data can cause long delays and considerable load on computer memory. For this reason, there appeared a need to implement algorithms in the database model, which would not cover large computer resources, i.e. the time of the processor and memory and which would require only one pass through the data.  Usefulness of the information obtained in this way is of paramount importance in web applications such as: analysis of streams, shopping cards, positioning in search engines

Temporal data model  Databases are based on two aspects of time: a) the period of validity of certain data, b) time of entry, the existence and the emergence of information in the database  These two attributes form bi-temporal data represented by four additional columns of the table: startVT and endVT and startTT and endTT. Expiration time presents the period in which the data are true in relation to the real world. In turn, the transaction time is the period in which data is stored in the database. It is worth mentioning that these two periods are not always identical.  A good example of this type of application are among others:  financial applications: portfolio management, accounting and banking applications,  repository-based applications: medical, human resource management, inventory management applications,  commercial applications: aerospace, railway, tourism, project management,  scientific applications.

Database Properties 1. Independence of applications and data: the data can be entered into the database without the necessity of modifying the application using them, and the applications can be modified independently of the state of the database. 2. An abstract representation of data: database management systems provide users with the representation of data that does not contain too many details concerning the techniques used and the implementation of data storage operations. 3. The diversity of data viewing: a typical database has multiple users, each of them may require access to data in a different way, this is achieved by the filters known as prospects?. 4. The physical and logical independence of data: the physical independence is represented by the possibility of extending or replacing hardware without affecting the data managed by the DBMS, and the logical independence separates the newly entered data in such a way as to not make existing data obsolete and not to remove other unrelated data.

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THEORETICAL FOUNDATIONS OF IT Prof. Witold Chmielarz, PhD Faculty of Management, University of Warsaw.

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THEORETICAL FOUNDATIONS OF IT Prof. Witold Chmielarz, PhD Faculty of Management, University of Warsaw.

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