System development Life-cycle

The six phases in the system development life cycle can be identified by different names.Also, there are no definite rules regarding what must be included in each of the six phases.

1 Initial investigation

This phase introduces the objectives of the initial investigation, the steps required toinitiate an investigation; the tasks involved in the initial investigation, and the datagathering and interviewing techniques. It also includes information and exhibits thatshould be in the initial investigation report, with regard to "How the standards manualmight be used ?" and "why to do this after reading this section."

2 Feasibility Study

This phase determines the objectives of the feasibility study and who this task belongs to --analysts or the project team? It lists out the steps required to complete a feasibility study,identifies the scope of the current system, problems and unexploited opportunities in thecurrent system, which may be either manual or automated. It then discusses the major objectives for the new system, and the various methods to gather data and determine how touse the methods. It also helps to estimate the costs of each possible solution, and developsestimates of the benefits and shortcomings of each solution. It presents users and themanagement views on the above issues and their decision of whether to commit to theanalysis part of the project. This phase may be included some related subphases:

•Current physical model: The descpription of the system as it is now, including themechanisms used to accomplish tasks (e.g., people, devices).

•Current logical model: The system description in term of functions, processes, and datawith the mechanisms removed.

• New Logical Model: The Current Logical Mode with new features added.

• New Physical Mode: The Current Logical Model with the various processes allocated toautomation, manual procedures, other mechanisms

3 General Design

Show the users the view of the application. In this phase, as well as the previous two, usersmust be directly involved. In this phase, The analysts’ imagination, creativity... and initiativeare used to their fullest. It also issues the System Flowcharts to develop. In addition, broadspecifications that describe how the data is to be processed by the computer will bedeveloped.

 4 Detailed Design

The Analysts have to transform from general design specifications to detailedrequirements that can be used in implementing the many tasks that make up thesystem. The final report should include the Procedural Flowchart, record and reportlayout, and a realistic plan for implementing the design. No major changes should bemade until the design is implemented and the system is operational, Then the programs for both transaction processing and batch jobs are executed. If there is the problems, the professional data processing staff is responsible for determining thecause and implementing a solution.

 5 Implementation

Detailed logic plans must be developed for all programs before they can be written,tested, and documented. After each procedure and program are tested, the system is tested.The conversion to the new system is made according to a plan developed in the detaileddesign phase. Many companies encourage their customers documenting their own systems.

6 System Audit

When the implementation report is submitted, an evaluation should be made to determinewhether the system meets the objectives stated in the general design report. In this phase,users may be able to suggest the easy-to-implement improvements.As in the six phase development life cycle, the project can be dropped at any point prior to implementation. A project may be dropped if the benefits  from the proposedsystem do not justify commitment of the needed resources. Or if the costs is higher, than expected.

 

The roles of Systems analysts

The system analyst is a key member of any systems development project. In a boarder sense, the systems analyst plays several roles:

• Archaeologist and scribe : As a systems analyst, one of the main jobs is to uncover detailand to document business policy that may exist only as “tribal folklore”, passed downfrom generation to generation of users.

•Innovator : The systems analyst must separate the symptoms of the user’s problem fromthe true causes. With his or her knowledge of computer technology, the analyst musthelp the user explore useful, new applications of computers.
•Mediator: The systems analyst who often finds himself in the middle of users,managers, programmers, auditors, and various other players, all of whom frequently disagree with one another.

•Project leader: Because the systems analyst is usually more experienced than the programmers on the project and since he is assigned to the project before the programmers begin working, there is a natural tendency to assign projectmanagement responsibilities to analyst.

This means that, as a systems analyst, you need:

1. More than just the ability to draw flowchart and other technical diagrams;
2. Skills to interview users, mediate disagreements;
3. Application knowledge to understand and appreciate the user’s business;
4. Computer skills to understand the potential uses of computer hardware and software inthe user’s business;
5. Able to view a system from many different perspectives;
6. Able to partition it into levels of subsystems;
7. Able to think of a system in abstract terms as well as physical term