System Development Life Cycle Phases

System Development Life Cycle (SDLC)

The System Development Life Cycle (SDLC) is a conceptual model used in project management. It describes the stages involved in an information system development project, from an initial feasibility study through maintenance of the completed application. Various SDLC methodologies have been developed to guide the processes involved, including the waterfall model, rapid application development (RAD), joint application development (JAD), the spiral model, prototyping model, and build and fix model.

Most organizations have a formal system development process consisting of a standard set of processes or steps they expect will be followed on any system development project. While these processes may vary greatly for different organizations, some common characteristics can be found. Most organizations' system development processes follow a problem-solving approach.

That approach typically incorporates the following general problem-solving steps:

• Identify the problem.
• Analyze and understand the problem.
• Identify solution requirements and expectations.
• Identify alternative solutions and the best course of action.
• Design the best solution.
• Implement the chosen solution.
• Evaluate the result.

The SDLC may be conceptualized into six sequenced stages:

(1) Recognition of Need: What is the Problem?

One must know what the problem is before it can be solved. The basis for the candidate system is recognition of a need for improving an information system. The objective of this step is to clearly define the need for the project. Defining the problem involves determining the exact nature of the problem, its location, and its likely causes. The objective is to understand the problem to enable finding an appropriate solution. This phase also sets the project boundaries, which define what part of the system can be changed by the project and what parts are to remain without any change. This also includes a rough idea of the resource requirements for the project, as well as the estimated start and completion dates for each phase and the number of persons to be involved in each phase.

In SDLC, problem identification helps in:

• Pinpointing the problems
• Setting proper system objectives
• Determining the boundaries of the project by taking into consideration the limitations of the available resources.

All projects that are requested are not always feasible. Some organizations receive so many project requests from employees that only a few of them can be pursued. Even those projects that are feasible and desirable should be put into a schedule. Management decides which requests are most important, and only after a project request is approved are the cost of the project, completion time, and personnel requirements estimated.

(2) Feasibility Study

A feasibility study is the test of a system proposal according to its workability, impact on the organization, ability to meet the user's needs, and effective use of resources. It focuses on the user's needs and how a candidate system meets them. It also focuses on the likely impact of the candidate system on the organization. The objective of a feasibility study is not to solve a problem but to acquire a sense of its scope. Under a feasibility study, the costs and benefits are estimated with greater accuracy.

The result of the feasibility study is the formal proposal. It is a formal document detailing the nature and scope of the proposed solutions.

The proposal summarizes what is known and what is going to be done. It consists of the following:

• Statement of the Problem: A carefully worded statement of the problem that led to analysis.
• Summary of Findings and Recommendations: A list of the major findings and recommendations of the study. It is ideal for users who require quick access to the results of the analysis of the system under study. Conclusions are also included.
• Details of Findings: An outline of the methods and procedures undertaken by the existing system, followed by coverage objectives and procedures of the candidate system.
• Recommendations and Conclusions: Specific recommendations regarding the candidate system, including personnel assignments, costs, project schedules, and target dates.