System Development Life Cycle (SDLC)

1. SystemDevelopmentLifeCycle (SDLC) A seriesofstepscompletedover a periodoftime byanalystsinthecourseof a systemdevelopment ormaintenanceproject. ThemainstepsoftheSDLCinclude - Analyzinghowthecurrentsystemmeetsusers’ informationneeds - Providing a designfor a newsystemor a modificationofanexistingsystemtomeettheseneeds - Developing a systembasedonthedesign - Implementingthesystem - Maintenance

2. System Development Life Cycle Phase 1 : Systems Planning and Preliminary Investigation Phase 2 : System Analysis Phase 3 : System Design Phase 4 : System Development Phase 5 : System Implementation and evaluation

3. Systems Request Phase 1 Preliminary Investigation Replace IS Preliminary Investigation Report Phase 2 Systems Analysis STOP System Requirements Document Phase 3 Systems Design STOP System Design Specification Phase 4 Systems Development STOP Complete Functioning IS STOP = Terminate Development Phase 5 Systems Implementation and Evaluation Waterfall model of SDLC Operational IS

4. Phase 1 : PreliminaryInvestigation • (FeasibilityStudy) • A written request from management or an end user • triggers the start of the systems development life cycle. • This written request is called a system request. • The purpose of the preliminary investigation phase is • to identify clearly the nature and scope of the problems • mentioned in the systems request. Because identifying the • problem is the focus of the preliminary investigation, this • phase is sometimes called the problem definition phase.

5. Phase 2 : SystemAnalysis • The purpose of the systems analysis phase is to • learn exactly what takes place in the current system, to • determine and fully document in detail what should take • place, and to make recommendations to management on • the alternative solutions and their costs. Through the • process of fact-finding or requirements determination, • You first define all the functions performed by the • current information system. At the same time, you • determine what modifications are needed by the • organization in the improved version of the information • system.

6. The endproduct you create for this life cycle phase is the system requirements document, which documents all end user and management requirements, all alternative plans and their costs, and your recommendations to management. After you present your results from this phase to management, management decides on the best alternative.

7. Phase 3 : SystemDesign • The purpose of the systems design phase is to • determine how to construct the information system to best • satisfy the documented requirements. You must design all • required information system outputs, files, inputs, • application software programs, and manual • procedures. • Also, you must design the internal and external controls, • which are computer-based and manual steps that • guarantee the information system will be reliable, • accurate, and secure.

8. The design is documented in the system design specification and is presented to the management and the end users for their review and approval. Management and end user involvement is critical so there is no misunderstanding about what the IS is to do, how it will do it, and what it will cost, After all systems design steps have been completed and if the developments is not terminated, you then enter the next phase, system development.

9. Phase4 : Systemdevelopment • System development is the phase during • which the information system is actually constructed: • application programs are written, tested, and • documented; operational documentation and • procedures are completed; and end user and • management review and approval is obtained. The • end product of this phase is a completely functioning • and documented information system. As is true with • all other phases, the system development phase ends • after management has reviewed and approved all • results of the phase.

10. Phase5 : Systemimplementation and • evaluation • After the system development phase is completed, • you then proceed to systems implementation. Activities • for this phase include conversion of data to the new • system’s files, final training of the end users, and the • transition from the old system to the new system. It is at • this point that the end users and management actually • begin to use the constructed IS. • As part of a complete systems development life • cycle, provision is made to allow for post- • implementation systems evaluation at regular intervals.

11. The purpose of these evaluations is to determine if the • information system operates as proposed, and if the costs • and benefits are as anticipated. • After the SDLC: system operation • During the systems operation phase, changes will • need to be made to the information system. These • changes are classified as either maintenance or • enhancements. Maintenance changes are made to correct • errors or to conform with government requirements. • Enhancements are modifications that add or change • capability within the system. Adding new information to • an existing printed report and the addition of new report • are examples of enhancements.

12. 1 Identifying problems,opportunities, and objectives 2 Determining information requirements 3 Analyzing system needs 7 Implementing and evaluating the system 4 Designing the recommended system 6 Testing and maintaining the system 5 Developing and documenting software

13. Systems planning Obsolete system New, related problem or requirement Systems support Systems analysis New implementation alternative or requirement Implementation error (bug) Systems implementation Systems design

14. The PIECES Framework by James Wetherbe P The need to improve performance. I The need to improve Information(or data). E The need to improve economics or control costs. C The need to improve control and security. E The need to improve efficiency of people and machines. S The need to improve service to customers, partners, employees, and so on.