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Lecture 3 Planning and Development Methodologies.

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Presentation on theme: "Lecture 3 Planning and Development Methodologies."— Presentation transcript:

1 Lecture 3 Planning and Development Methodologies

2  Definition  Reasons for new system  Traditional Systems Development  Lifecycle  Analysis Techniques  The role of the systems analyst  CSF’s and KPI’s  Types of methodology  SSADM, SSM and RAD (Pro’s and Con’s)  Alternative solutions (Pro’s and Con’s)

3 From the Greek “Study of Methods” A methodology can be defined as: “a collection of procedures, techniques, tools and documentation aids which help the systems developers in their aim to implement a new information system” Avison and Fitzgerald (1996)

4  Current system can’t cope  Time saving  Cost saving  Information for decisions  Competitive advantage for organisation  Competitive service for customers  New technology image  New legal requirements

5  5 Stage process:  Investigation  Analysis  Design  Implementation  Maintenance Investigation Analysis Design Implementation Maintenance

6  Detect business problem/opportunity  Conduct feasibility study  Cost vs. Benefits  Most costs are tangible, but most benefits are not  Develop project plan  Obtain approval

7  Information needs of end users.  Current systems (computer or otherwise)  Develop functional requirements

8  Procedure Narratives  Data Flow Diagrams  Entity Relationship Models

9  Describes in basic steps exactly what happens in a process  Good for recording processes in detail  But  Can be too detailed  Does not show any dynamic relationships

10  Shows relationships between entities and processes both inside and outside the system  Can have several layers of detail  Mainly used for ‘hard’ methodologies

11  AKA Logical Data Models  Show underlying meaning to DFD’s  Logical Data Structure  Diagram and descriptions  Entity Life History  Documents stages of entity development

12  Specify:  Hardware  Software  Users  Data resources  Information products (reports etc.)

13  Acquire components  Convert data  Test system  Train users  Make new system operational  Different methods:  Parallel, Phased, Cut Off  Pro’s and Con’s

14  Review system’s functions  Gain user’s feedback  Monitor  Evaluate  Modify where necessary

15  Investigation of the existing system  Managing the feasibility study  Conceptual design (logical)  Overseeing the testing  Coordinating the implementation  Evaluation of the system performance  Must be a good communicator

16  Critical Success Factors:  Operational goals  Hospital – We need to use our Operating Theatres more effectively  Key Performance Indicators:  Measurement of success  Hospital – Number of hours OT is idle - Number of operations performed - Are numbers enough?

17 Business problem/opportunity Exploration of problem Fully explore what is needed Full design brief Design Build Implement RAD ETHICS SSADM SSM IE

18  Expanded the 5 point list to 7 (version 4)  Feasibility  Investigation of current environment  Business system options  Definition of requirements  Technical system options  Logical design  Physical design

19  Benefits  Excellent where requirements are defined and structured  Disadvantages  Time consuming  Costly  Inflexible

20  ‘An organised way of tackling a messy situation’ (Checkland and Scholes)  Developed to help with unstructured and poorly defined problems  Centres on individual’s experiences of the problem  Therefore, ‘right information’ rarely exists

21  Situation considered problematic  Problem expressed  Definition of purposeful activity  Conceptual systems models  Comparison (model to real world)  Changes  Action to improve problem situation (Systems thinking) (Real world)

22

23  Prototyping (RAD)  Application Software Packages  End – User Development  Outsourcing

24  An experimental system, put together quickly for feedback from users  The prototype is a working version of all or part of the system  Users’ requirements are met by constant refining through iterative processes

25 Identify basic requirements Develop a working prototype Use the prototype User feedback positive? Revise the prototype Operational prototype No Yes

26  Viable alternative to some bespoke systems development  Off-the-shelf packages for more and more solutions  Implementation time and costs greatly reduced  May not meet all requirements

27  Increasingly used in today’s organisations  Easier to define user requirements  Benefits:  Increase in user satisfaction / productivity  Disadvantages:  Documentation?  Managerial control?  Ownership

28  The hiring of an external organisation  Benefits:  Reduces need for IS department  Accommodate fluctuating needs  Disadvantages:  Loss of control over:  Technology  Competitive advantage  Own IS function

29  The development of a system should be managed through the use of a suitable methodology  As many different development methodologies exist as there are systems  Alternative approaches such as EUD and outsourcing exist  The whole process should be managed by a systems analyst


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