SDLC (system development life circle) describes a life circle of planning, creating, controlling and executing an information system. It consists of clearly defined phases, which are supposed to help system developers to consider client´s demands and stay within a certain budget as well as stick to a timetable. SDLC was developed in the 1960ies in order to keep an overview of the growing complexity. Moreover, frameworks that support IT- projects were developed later based on SDLC. 1)
SDLC consists of seven phases, each based on the one prior and is a tool to help developers with planning, developing and controlling a project. These phases will be explained as follows.2)
During the first phase it is determined which changes, reformations and improvements are necessary and can be of use for the project. In most cases, a feasibility study is conducted in order to prioritize requirements. This phase is essential for conducting a cost overview and estimating the expected expenditure of time. 3)
After defining which problem is to be solved, it has to be decided on how to solve it. During the phase of system analysis the affected system is broken down into little pieces. This is supposed to help find the origin of the problem. Furthermore, the project aims are defined, the client’s requests are analyzed and risks are identified. 4)
During the design phase the specific details of the project are defined and are documented, taking into account the business´ rules and the client´s requests.5)
The priory defined modules are established and the program code is written during the implementation phase, which is the most complex phase for the developers. It is also the most time consuming phase. Additionally, the developers establish test cases, which will be essential during the next phase. 6)
After writing the program code, the test cases developed during the implementation phase are used in order to identify mistakes within the program code. It is essential for its success to find these mistakes as early as possible, since the IT- systems depend on each other. Therefore, specialist literature often refers to this as “testing while developing”. 7)
If the test cases conducted earlier all turn out to be successful, the established program is embedded into the corporation. Moreover, various coachings and sensitizations are conducted with the client. 8)
During the last phase of the SDLC the new systems usefulness is measured in order to determine which of the intended improvements are actually fulfilled.
In literature SDLC is described as a useful tool to keep control of IT- projects. Due to steps described in detail and standardized designs developers get a valuable overview of what to do next. Despite of the many benefits of SDLC, it also has some disadvantages. For example it proofs to be rather inflexible due to its specific procedure. Additionally, it is difficult to estimate the exact cost and expenditure of time.