RUCHU GIRLS SECONDARY SCHOOL

1. RUCHU GIRLS SECONDARY SCHOOL PRESENTERS: Ruth Muma June Sela

2. SYSTEM DEVELOPMENT Definition: System-a collection of personnel, equipment, and methods organized to accomplish asset of specific function. Information System-It is a set of procedures automated or manual that comprises of people, machines and methods to collect, process, store, transmit and disseminate information.

3. USES OF INFORMATION SYSTEM • Management of large or small organizations. • Improve performance of organizations. • Keep track of transactions E.g. orders and bills. • Speed up with the decision making process. • It gives competitive advantage over rivals. -Systems are of two types i.e. Soft system Hard System

4. Classifications of Systems • Systems are classified into three: Deterministic System Probabilistic System Cybernetic System • System Development Cycle • A well develop system provide the following: • It should be maintainable • It should be reliable • It should be efficient • It should be user friendly interface

5. Software development uses models derived from engineering activities .e.g. The Water Fall Model or SDLC. • SDLC presents system development that systematically links with each other to form a final product. It should be structured as follows: • System planning • System analysis • System design • System implementation and unit test • System operation and support

6. Water Fall Model Phase 1 System Planning System Analysis Phase 2 Phase 3 Preliminary Investigation Report System Design System Requirement documentation Implementing & Testing Stop Development Project Design Specification Stop Development Function Information System Phase 4 Stop Development Operational Information System Operation & Support

7. Reasons For System Failure • Inadequate user involvement • Continuation of a project that should have been cancelled • Failure in system integration NB:to avoid failure SDLC is used to direct and administer activities

8. Phase 1:system planning • It is the stage where a written test is made known as system request or request for proposal (RFP) Reasons for a system project • Improved service to customers • Reduced cost of operation • Better performance • Need for stronger controls • Need for information for decision making

9. Feasibility study This is the valuation of a system request to determine whether it is worth while to proceed with the project It has 4 test: Economical feasibility Technical feasibility Operational feasibility Schedule feasibility

10. PHASE 2 –System analysis It forms the foundation of building an information system. Its main objective: • To learn exactly how the system works • Determine and document fully how the system could work • To develop a logic business related model of the proposed system and make recommendations to the management. System analysis involves three steps • Requirements determination • Requirements analysis • Evaluating alternative strategies

11. System requirements determination It ensures the new information system satisfies the users requirement one has to identify business related reqiurments.including output,input,procces timings and controls some of the fact finding techniques are: Interviews Questionnaires Observation Document review User workshop Automated method

12. Requirement analysis The analyst mustget the fact to identify problem, their causes aid opportunity for improvement and these uses the following: Data Flow Diagram (DFD)-It illustrate how data is processed by a system in terms of input and output. Data dictionary-a collection of data elements definition Process description-a detailed description of the processed used e.g. flowcharts and pseudo codes.

13. Data Flow Diagrams They show the flow of data through a system for its margin to its destination. They are used for clarification in any phase of SDLC It uses two types of notations i.e. Yourdon and coad Gane and sarson

14. PROCESS A process transforms incoming data flow and outgoing data flow. They are represented as follows: 1 Process Process YOURDON AND COAD Information Process GANE AND SARSON

15. DATA STORE This is where data is kept in a system often referred to as a file. Its represented as follows: YOURDON AND COAD GANE AND SARSON or

16. Diagrams flow diagram • They pipeline through whichpackets of information flow The arrows are labeled with the name of data that moves through it e.g.

17. KENYAN NAME AGE WELCOME FOR INTERVIEW NO VACANCY ID NUM EDUCATION Store file JOB EXPERIENCE EXAMPLE OF DFDJOB APPLICATION New Member State your nationality ADD NAME No name 18 and above 18 No vacancy Below 18 Your ID nun not educated level of education professional educated

18. PHASE 3-System design • it involves two main objective; • To design the new system • To establish a sound frame work of controls within the new system should operate To do this one has to consider the following requirements: Input Processing Output Storage System controls Back ups

19. PHASE 4-SYSTEM DEVELOPMENTS,TESTING At this stage the analyst must provide clear and accurate specification to the programmers. A knew system requires planning ,construction, andtesting IMPLEMENTATION There are four basic approaches of implementation • Direct • Parallel • Phased • pilot

20. Phase 5-system dev and support It is the last phase in SDLC it begins when the system becomes operational and ends when it is replaced It involves maintenance and improvements to the system MAINTAINANCE They include changing programs, procedures or documentation to ensure correct system performance There are various types of maintenance • Corrective maintenance • Adaptive maintenance • Perfective maintenance