Methodologies identify phases and actions, and the amount and scope of these phases and procedures may differ from one designer to the other, expert to expert, technique to technique, and business to business. The phases are:
1) Scope definition:
This is the first phase of a typical project is scope definition. The function of the scope definition phase is twofold. Initially, this answers the question, “Are there issues which merit examining?” Next, and if the issue merits examination, it establishes the extent and boundaries of the project, the project vision, any constraints or boundaries, the necessary project participants, and the schedule and budget.
2) Problem analysis:
The problem analysis phase analyzes the existing system and the findings to supply the project team with a more methodical perceptive of the problems that started the project. The analyst repeatedly uncovers and reviews the latest issues and answers the most significant question, “Will it be profitable to solve these problems or will this exceed the budget to build the system that would explain these issues?”
3) Requirements analysis:
The requirements analysis phase sets priorities and defines the requirements for the business. The analyst approaches the users to discover what is needed and what the business wants the new system, cautiously avoiding any dialogue of technical execution. This is the most vital phase of the systems development. Omissions and errors in the requirements analysis may affect the project and cause user dissatisfaction with the finished system and can cause a budget deficit from a costly modification
4) Logical design:
The logical design phase translates business necessities into system models. The phrase logical design is interpreted as “technology independent,” meaning the pictures demonstrate the system independents of any possible technical explanation, and the systems model business requirements which have to be satisfied by whichever technical solution that is considered.
5) Decision analysis: (a system analysis transition phase)
The purpose of the decision analysis phase is to (I) recognize candidate technical solutions, (II) evaluate those solutions which are considered for achievability, and (III) advice a candidate system as the goal solution to be designed.
6) Physical design and Integration:
Physical design is the reverse of the logical design. The function of the physical design and integration phase is to convert the business necessities (partly by using the logical system models) into physical design specifications which facilitate the systems assembly. Physical design addresses larger element about how the technology will be put to use in the new system. The design will be constrained by the accepted architectural model from the prior phase. It is necessary for the design to adhere to all interior technical design principles that will make certain performance, usability, quality, reliability, and completeness.
7) Construction and Testing:
The construction and testing phase is a functional system that is ready for implementation. The reason of the construction and testing phase consist of two parts: (I) to build and test a system that fulfills business requirements and physical design specifications, and (II) to execute the interfaces linking the new system and existing systems. Any final documentation (any technical documents, such as: training manuals and help references) will be developed during the groundwork for instruction and system operation. The construction phase may also include installation of any software that has been purchased.
8) Installation and Delivery:
The installation and delivery phase is the deliverable operational system. The system changes from the environment of development into the production environment. System analysts must provide training to system users, write various production control and user manuals, and transfer existing files and databases into new databases, and carry out a final testing of the system. Any problems may instigate a rework of previous phases which were thought to be completed. System users can supply feedback as any new issues arise. The installation and delivery phase uses similar building blocks as the construction phase.
“These phases are not absolutely sequential. The phases tend to overlap one another; in addition, the phases may be modified to the unique requirements of a given project (e.g., deadlines, complexity, strategy, resources)”. Whitten−Bentley: Systems Analysis and Design Methods, Seventh Edition
© The McGraw−Hill Companies, 2007
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