1. Essentials of Systems Analysis and Design Fifth Edition Joseph S. Valacich Joey F. George Jeffrey A. Hoffer Chapter 1 The Systems Development Environment Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall 1.1

2. Learning Objectives Define information systems analysis and design Discuss the modern approach to SAD that combines process and data views Describe the role of the systems analyst Describe the SDLC and alternatives Describe role of computer aided software engineering (CASE) tools Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall 1.2

3. Chapter Preview Systems Analysis is a proven method to help business utilize information to its fullest capacity Systems Development Life Cycle (SDLC) is central to the development of an efficient information systems Four key SDLC steps: Planning and selection Analysis Design Implementation Note that these steps may vary in each organization depending on its goals.

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5. What is Information Systems Analysis and Design? A method used to create and maintain systems that perform basic business functions Main goal - to improve employee efficiency by applying software solutions to key business tasks A structured approach to ensure success Systems Analysts perform SAD based upon: – Understanding of organization’s objectives, structure and processes – Knowledge of how to exploit information technology for advantage Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall 1.6

6. Systems Analysis and Design: Core Concepts Major goal: to improve organizational systems by developing or acquiring application software and training employees in its use Application software (or a System): Designed to support a specific organizational function or process – It is goal to turn data into information – In addition to application software, the information system includes: Hardware and system software Documentation and training materials Job roles associated with the system Controls to prevent theft or fraud The people who use the software to perform their jobs Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall 1.6

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9. – Methodologies A sequence of step-by-step approaches that help develop the information system. Incorporate several development techniques – Techniques Processes that the analyst follows to ensure thorough, complete, and comprehensive analysis and design – Conducting thorough interviews with current and future users – Planning and managing the activities in a systems development project – Diagramming how the system will function – Tools Computer programs that aid in applying techniques These three elements work together to form an organizational approach to systems analysis and design Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall 1.9

10. System A system is an interrelated set of business procedures used within one business unit working together for a purpose A system exists within an environment A boundary separates a system from its environment A system has nine characteristics Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall 1.10

11. Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall 1.11 Characteristics of a System › Purpose (Subsystem) › Environment (everything outside the system’s boundary that influences the system) › Boundary › Interrelated Components › Interrelationships › Constraints › Interfaces › Input (from its environment) › Output (to its environment)

12. Important System Concepts Decomposition – The process of breaking down a system into smaller components – Allows the systems analyst to: Break a system into small, manageable and understandable subsystems Focus on one area at a time, without interference from other areas Concentrate on component pertinent to one group of users without confusing users with unnecessary details Build different components at independent times and have the help of different analysts Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall 1.12

13. Important System Concepts Modularity: direct result of decomposition – Process of dividing a system into modules of a relatively uniform size – Modules simplify system design Coupling – Subsystems that are dependent upon each other are coupled – Desired: loose coupling Cohesion – Extent to which a subsystem performs a single function – Desired: high cohesion Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall 1.13

14. Cohesion and Coupling 1 234 56 High cohesionLow coupling Bridge component  Adapted from Software Engineering: An Object-Oriented Perspective by Eric J. Braude (Wiley 2001), with permission. Effective modularization = max. cohesion within modules + min. coupling between modules

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16. A Modern Approach to Systems Analysis and Design Systems Integration – Allows hardware and software from different vendors to work together – Enables procedural language systems to work with visual programming systems – Visual programming environment uses client/server model Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall 1.16

17. SA role in Systems Development Study problems and needs of an organization Determine best approach to improving organization through use of: – People – Methods – Information technology Help system users and managers define their requirements for new or enhanced information systems Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall 1.17

18. Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall 1.18 Systems Development Methodology … e.g. SDLC

19. Copyright © 2009 Pearson Education, Inc. Publishing as Prentice Hall Your Skills As System Analyst (1) Analytical skills: to understand the organization and its functions, to identify opportunities and problems, and to analyze and solve problems. – Systems thinking: ability to see organizations and information systems as systems. Provides a framework from which to see the important relationships among information systems, the organizations they exist in, and the environment in which the organizations themselves exist. 1.19

20. Copyright © 2009 Pearson Education, Inc. Publishing as Prentice Hall Your Skills As System Analyst (2) Technical skills: help you understand the potential and the limitations of information technology. – Able to work with programming language, various operating systems and computer hardware platforms 1.20

21. Copyright © 2009 Pearson Education, Inc. Publishing as Prentice Hall Your Skills As System Analyst (3) Management skills: help you manage projects, resources, risk, and change (4) Interpersonal skills: help you work with end users as well as with other analysts and programmers – Effective written and oral communication Leading meetings Interviewing end users and listening 1.21

22. Copyright © 2009 Pearson Education, Inc. Publishing as Prentice Hall Developing Information Systems and the Systems Development Life Cycle Systems Development Methodology – A standard process followed in an organization to conduct all the steps necessary to analyze design implement and maintain information systems. 1.22

23. Copyright © 2009 Pearson Education, Inc. Publishing as Prentice Hall Developing Information Systems and the Systems Development Life Cycle (continued) Systems Development Life Cycle – A common methodology for systems development in many organizations – Series of steps used to manage the phases of development for an information system – Consists of four phases: Planning and Selection Analysis Design Implementation and Operation 1.23

24. Copyright © 2009 Pearson Education, Inc. Publishing as Prentice Hall Systems Development Life Cycle Although it looks as a sequentially ordered set of phases, it actually is not. – The specific steps and their sequence are meant to be adapted as required for a project – The project can return to an earlier phase, if necessary – It is also possible to complete some activities in one phase in parallel with some activities of another phase 1.24

25. Copyright © 2009 Pearson Education, Inc. Publishing as Prentice Hall Systems Development Life Cycle It is also possible to complete some activities in one phase in parallel with some activities of another phase. Sometimes the life cycle is iterative; that is, phases are repeated as required until an acceptable system is found. Some systems analysts consider the life cycle to be a spiral, in which we constantly cycle through the phases at different levels of detail, as illustrated in Figure 1-10. 1.25

26. Copyright © 2009 Pearson Education, Inc. Publishing as Prentice Hall Systems Development Life Cycle Even if a particular methodology does not look like a cycle, many of the SDLC steps are performed, and SDLC techniques and tools are used. This book follows a generic SDLC model You can apply this methodology to almost any life cycle Each phase has specific outcomes and deliverables that feed important information to other phases. 1.26

27. Copyright © 2009 Pearson Education, Inc. Publishing as Prentice Hall Phases of the Systems Development Life Cycle 1.Systems Planning and Selection – Two Main Activities (a) Identification of need: someone identify the need for a new or enhanced system. Information needs are examined, and projects to meet these needs are identified. The needs may result from – Problems in current procedures – Desire to perform additional tasks – Using information technology to capitalize on an existing opportunity During the systems planning and selection phase, an organization determines whether resources should be devoted to the development or enhancement of each information system under consideration. A feasibility study should be conducted to determine the economic and organizational impact of the system 1.27

28. Copyright © 2009 Pearson Education, Inc. Publishing as Prentice Hall Phases of the Systems Development Life Cycle 1.Systems Planning and Selection – Two Main Activities (b) Investigation and determination of scope: The team of systems analysts then produces a specific plan for the proposed project for the team to follow. This plan specifies the time and resources needed for its execution 1.28

29. Copyright © 2009 Pearson Education, Inc. Publishing as Prentice Hall Phases of the Systems Development Life Cycle 2.Systems Analysis – Study of current procedures and information systems Determine requirements Generate alternative designs match the requirements Compare alternatives to see which best meets the requirements within the cost, labor, and technical levels the organization is willing to commit to the development process Recommend best alternative 1.29

30. Copyright © 2009 Pearson Education, Inc. Publishing as Prentice Hall Phases of the Systems Development Life Cycle (continued) 3.System Design: convert the description of the recommended alternative solution into logical and then physical system specification – Logical Design Concentrates on business aspects of the system, that is, how the system will impact the functional units within the organization – Physical Design Technical specifications: programming languages, database systems and file structures, hardware platform, operating system and network environment 1.30

31. Copyright © 2009 Pearson Education, Inc. Publishing as Prentice Hall Phases of the Systems Development Life Cycle (continued) 4.System Implementation, Operation and Maintenance : – Turn system specifications into a working system that is tested and then put into use – Implementation Coding Testing Installation: the new system becomes a part of the daily activities of the organization User Training Documentation Maintenance (fix errors, make changes) 1.31

32. Copyright © 2009 Pearson Education, Inc. Publishing as Prentice Hall Phases of the Systems Development Life Cycle (continued) System Implementation, Operation and Maintenance(continued) During operation, programmers make the changes that users ask for and modify the system to reflect changing business conditions System obsolescence 1.32

33. Alternative Approaches to Development Prototyping – Building a scaled-down working version of the system – A prototype can be developed with a CASE tool, a software product that automates steps in the systems development life cycle. – CASE tools make prototyping easier and more creative by supporting the design of screens and reports and other parts of a system interface. Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall 1.33

34. Prototyping Advantages: – Users are involved in design – Captures requirements in concrete form Disadvantages: – Users may misunderstand SD complexity – Code often thrown away Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall 1.34

35. Prototyping Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall 1.35

36. Automated software tools used by systems analysts to develop information systems Project management tools (Openproj, MS Project) Diagramming tools (Dia, Visio) Computer display and report generators (VB) Analysis tools (Visual Analyst) Documentation generators Code generators Integration of tools via a repository Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall 1.36 Computer-Aided Software Engineering (CASE) Tools

37. An Example

38. The general types of CASE tools include: Diagramming tools that enable system process, data, and control structures to be represented graphically. Computer display and report generators that help prototype how systems “look and feel” to users. Display (or form) and report generators also make it easier for the systems analyst to identify data requirements and relationships. Analysis tools that automatically check for incomplete, inconsistent, or incorrect specifications in diagrams, forms, and reports. A central repository that enables the integrated storage of specifications, diagrams, reports, and project management information. Documentation generators that help produce both technical and user documentation in standard formats. Code generators that enable the automatic generation of program and database definition code directly from the design documents, diagrams, forms, and reports.

39. Alternative Approaches to Development Joint Application Design (JAD) – Users, Managers and Analysts work together for several days – System requirements are reviewed – Structured meetings – By gathering the people directly affected by an IS in one room at the same time to work together to agree on system requirements and design details, time and organizational resources are better managed Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall 1.39

40. Alternative Approaches to Development Rapid Application Development (RAD) – Prototyping, CASE, and JAD are key tools that support rapid application development (RAD) – The fundamental principle of any RAD methodology is to delay producing detailed system design documents until after user requirements are clear – RAD involves gaining user acceptance of the interface and developing key system capabilities as quickly as possible Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall 1.40

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42. Participatory Design Developed in northern Europe, participatory design (PD) represents a viable alternative approach to the SDLC. PD emphasizes the role of the user much more than do traditional North American techniques such as structured analysis and structured design. In some cases, PD may involve the entire user community in the development process. Each user has an equal voice in determining system requirements and in approving system design. In other cases, an elected group of users controls the process. These users represent the larger community, much as a legislature represents the needs and wants of the electorate. Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall 1.42

43. Agile Methodologies Extreme Programming, Adaptive S/W Development, Scrum These Agile Methodologies share three key principles: Adaptive methodologies rather than predictive People instead of roles Self-adaptive development process Adopting an adaptive rather than predictive methodology refers to the observation that engineering based methodologies work best when the process and product are predictive. Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall 1.43