· Identifying the problem (user requirement)
· Feasibility Study
· System Analysis
· System Design
· Software Development
· Testing
· Implementation
· Maintenance
Identifying the problem (user requirement)
The initiation of a system begins when a business need or opportunity is identified. this is called identifying the problem. A Project Manager should be appointed to manage the project. This business need is documented in a Concept Proposal. After the Concept Proposal is approved, the System Development Phase begins.
Feasibility Study
Phase Two of the SDLC is a Feasibility study. It's known what the system is to accomplish, now it needs to be decided if the system CAN be built feasibly. Feasibility is based on three main factors.
1. Do we have the technology to construct the system we want?
2. Is the project fiscally possible (i.e. can the purchaser afford it)?
3. Is it practical for the system to be built?
Do we have the technology to construct it? This question is almost a misnomer, it is rare to find a system that we cannot construct with the tech level that we currently have ... but there will be times when technology will be a limiting factor. More than likely, however, the technology will be there, it is just a matter of deciding if the cost can be justified...
Fiscal feasibility. Is the gain(s) made by the new system worth the cost of producing the new system? How much does it cost to maintain the current system (actual maintenance costs, lost revenue due to poor service, loss of productivity caused by waiting for the old system, etc.)
System Analysis
In this phase, the systems analysts study the existing system in detail, and identify new requirements. Analysis gathers the requirements for the system. This stage includes a detailed study of the business needs of the organization. Options for changing the business process may be considered
System design
Design focuses on high level design like, what programs are needed and how are they going to interact, low-level design (how the individual programs are going to work), interface design (what are the interfaces going to look like) and data design (what data will be required). During these phases, the software's overall structure is defined. Analysis and Design are very crucial in the whole development cycle. Any glitch in the design phase could be very expensive to solve in the later stage of the software development. Much care is taken during this phase. The logical system of the product is developed in this phase
Software Development
In this phase the designs are translated into code. Computer programs are written using a conventional programming language or an application generator. Programming tools like Compilers, Interpreters, Debuggers are used to generate the code. Different high level programming languages like C, C++, Pascal, Java are used for coding. With respect to the type of application, the right programming language is chosen (The design specifications are converted into source code of a programming language.)
Testing
In this phase the system is tested. Normally programs are written as a series of individual modules, these subject to separate and detailed test. The system is then tested as a whole. The separate modules are brought together and tested as a complete system. The system is tested to ensure that interfaces between modules work (integration testing), the system works on the intended platform and with the expected volume of data (volume testing) and that the system does what the user requires (acceptance/beta testing).
7 Implementation
The implementation stage of any project is a true display of the defining moments that make a project a success or a failure. The implementation stage is defined as "the system or system modifications being installed and made operational in a production environment. The phase is initiated after the system has been tested and accepted by the user. This phase continues until the system is operating in production in accordance with the defined user requirements" While all of the planning that takes place in preparation of the implementation phase is critical and important.
7 Maintenance
Inevitably the system will need maintenance. Software will definitely undergo change once it is delivered to the customer. There are many reasons for the change. Change could happen because of some unexpected input values into the system. In addition, the changes in the system could directly affect the software operations. The software should be developed to accommodate changes that could happen during the post implementation period.
Some e-books and web sites give various definitions and explanations about phases of SDLC. Following is also an other description about phases of SDLC and it can be used as optional steps.
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