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Lecture IS3318 12/3/12. Figure 6-6 Microsoft Access has a rudimentary data dictionary capability that displays information about the size, format, and.

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Presentation on theme: "Lecture IS3318 12/3/12. Figure 6-6 Microsoft Access has a rudimentary data dictionary capability that displays information about the size, format, and."— Presentation transcript:

1 Lecture IS3318 12/3/12

2 Figure 6-6 Microsoft Access has a rudimentary data dictionary capability that displays information about the size, format, and other characteristics of each field in a database. Displayed here is the information maintained in the SUPPLIER table. The small key icon to the left of Supplier_Number indicates that it is a key field. Microsoft Access Data Dictionary Features The Database Approach to Data Management

3 Some Drawbacks… Complexity A DBMS is a complex piece of software all users must fully understand it to make use of its functionalities Cost of DBMS The cost varies significantly depending on the environment and the functionality provided. Must take into consideration recurrent annual maintenance costs 3

4 Continued.. Cost of Conversion Cost of converting existing applications to run on the new DBMS and hardware. (additional training costs) Performance DBMS is written for applications in general which means that some applications may run slower than before Higher Impact of Failure Centralization of resources increases vulnerability of the system 4

5 Database Administrator Oversees a staff of database specialists Final recommendations for DB design Load and maintain DB Establish security controls Perform backup and recovery 5

6 Data Administration Database Management System Data planning and modelling technology Database technology And management Data Administrator Users 6

7 Systems Analyst Or business analyst is a systems analyst that specializes in business problem analysis and technology- independent requirements analysis. A programmer/analyst (or analyst/programmer) includes the responsibilities of both the computer programmer and the systems analyst. Other synonyms for systems analyst include: Systems consultant Systems architect Systems engineer Information engineer Systems integrator 7

8 Role of the Systems Analyst 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 systems 8

9 Skills of a Successful Systems Analyst Analytical Understanding of organizations. Problem solving skills System thinking Ability to see organizations and information systems as systems Technical Understanding of potential and limitations of technology. 9

10 Skills of a Successful Systems Analyst Managerial Ability to manage projects, resources, risk and change Interpersonal Effective written and oral communication skills 10

11 System Owners System owners are the information system’s sponsors and chief advocates. They are usually responsible for funding the project to develop, operate, and maintain the information system. 11

12 System Users System users are the people who use or are affected by the information system on a regular basis—capturing, validating, entering, responding to, storing, and exchanging data and information. A common synonym is client. Types include: Internal users Clerical and service workers Technical and professional staff Supervisors, middle managers, and executive managers Remote and mobile users (internal but disconnected) External users 12

13 Stakeholders: Players in the Systems Game A stakeholder is any person who has an interest in an existing or new information system. Stakeholders can be technical or nontechnical workers. For information systems, the stakeholders can be classified as: System owners System users Systems analysts System designers System builders IT vendors and consultants 13

14 Systems Development Lifecycle (SDLC) The systems development life cycle (SDLC) model is an approach to developing an information system or software product that is characterised by a linear sequence of steps that progress from start to finish without revisiting any previous step. The SDLC model is one of the oldest systems development models and is still probably the most commonly used. 14

15 SDLC Traditional systems development lifecycle (Waterfall Model) SDLC - very similar to a product life cycle in the consumer market because both a new product and information system develop through a number of stages. 15

16 The typical SDLC has the following steps: Initiation Feasibility study System Investigation System Analysis Systems Design Implementation Review and Maintenance These stages are frequently referred to as “conventional systems analysis”, “traditional systems analysis”, “the systems development life-cycle” or the Waterfall Model 16

17 SDLC or The Waterfall Model The waterfall model describes a development method that is linear and sequential. Once a phase of development is completed, the development proceeds to the next phase and there is no turning back. The advantage of waterfall development is that it allows for departmentalisation and managerial control. 17

18 The Waterfall Model Continued.. A schedule can be set with deadlines for each stage of development and a product can proceed through the development process and theoretically, be delivered on time. Development moves from concept, through design, implementation, testing, installation, troubleshooting, and ends up at operation and maintenance. 18

19 19 Initiation Analysis Investigation Implementation Design Maintenance Traditional SDLC NO FEEDBACK!!!!

20 SDLC This is now regarded as the “hard” systems approach because of its rigid demarcation between phases. It has shortfalls which lead to a number of difficulties One major criticism of the model is that it doesn’t cater for revisiting previous phases to correct defects. Feedback Loop – refinement of Waterfall Model 20

21 Potential Strengths of the Traditional SDLC It has been well tried and tested Use of documentation standards Following the methodology should aid (At least to some extent) that roll out dates, budgets and expected benefits are met. At the end of each phase, all parties involved in the project can review progress. Much greater control on the development of computer applications and make possible the use of project management tools and techniques 21

22 Potential Weaknesses of the Traditional SDLC Criticisms of the methodology or perhaps of the way it was used include: Failure to meet the needs of management Unambitious systems design Instability Inflexibility User dissatisfaction Problems with documentation Lack of control 22

23 Potential Weaknesses of the Traditional SDLC Incomplete systems Application backlog Maintenance workload Problems with the “ideal” approach It does not allow for much reflection or revision. 23

24 Prototyping Building an experimental system rapidly and inexpensively for end users to evaluate It will be refined until it conforms to the users’ requirements This is achieved through iterative development 24

25 Advantages of Prototyping Useful when there is uncertainty about system requirements or systems design Valuable for End-user interface design Encourages end-user involvement throughout the systems development lifecycle 25

26 Disadvantages of Prototyping Better suited for smaller application development. Prototyping may mean glossing over essential steps in the system development. 26

27 Application Software Packages A set of prewritten, precoded application software programs that are commercially available for sale or lease Packages have increased as many applications are common to many businesses: payroll, accounts and inventory control 27

28 Advantages of Software Packages Most of the design work has been completed in advance Little extensive testing required Vendor support and maintenance 28

29 Disadvantages of Software Packages Disadvantages may be increased with a complex system Required customisation and additional programming may be expensive Hidden implementation costs 29

30 End User Development The development of information systems by end users with little or no formal assistance from technical specialist It has been made possible by fourth generation software tools (4GL) 30

31 Encouraging End User Development The variety of application development tools available make it easier for end user development Guidelines for managers to encourage intranet website development by end users: Look for what makes sense Spur creativity Set some limits Give managers responsibility Make users comfortable 31

32 Advantages to End User Development Improved requirements determination Increased user involvement and satisfaction Reduced application backlog 32

33 Risks of End User Development It occurs outside the traditional mechanisms for information system management and control Problems in ensuring that end-user developed applications meet organisations objectives and standards Rapid systems development without a formal methodology may mean that testing and documentation is inadequate Loose control of organisational data 33

34 Definition - Outsourcing The practice of contracting computer centre operations, telecommunications networks, or application development to external vendors Example: Bank of Ireland, Dell 34

35 Outsourcing Outsourcing has become increasingly popular as companies believe that it is more cost effective than maintaining their own IS staff Many companies are outsourcing software procurement and support to application service providers (ASPs) who provide and support business application and other software via the Internet and intranets to all of a company’s employees workstations 35

36 Benefits of Outsourcing To reduce work in the information systems department. When the IS function within an organisation is limited. To improve the contribution of IT to enhance business performance. To create new sources of revenue. 36

37 Benefits of Outsourcing To reduce work in the information systems department When the IS function within an organisation is limited To improve the contribution of IT to enhance business performance To create new sources of revenue 37

38 Risks associated with Outsourcing May loose control over IS function Heavy reliance on the vendor Proprietary information may be leaked to the competition if sensitive data is available outside the organisation 38

39 Sample Questions Discuss Porter’s Competitive Forces Model, considering the role of information systems in gaining competitive advantage. Illustrate your answer with diagrams and examples. Outline and briefly explain the stages involved on the Systems Development Lifecycle (SDLC).

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