What is SDLC?
The systems development life cycle (SDLC), also referred to as the application development life-cycle, is a term used in systems engineering, information systems and software engineering to describe a process for planning, creating, testing, and deploying an information system.
Career Paths for System Developers
Systems Development Life Cycle
- Building an information system using the SDLC follows a similar set of four fundamental phases:
The Systems Development Life Cycle
- Each phase is itself composed of a series of steps , which rely on techniques that produce deliverables (specific documents and files that explain various elements of the system).
- The planning phase is the fundamental process of understanding why an information system should be built and determining how the project team will go about building it. It has two steps:
- 1. Project initiation
- 2. Project management
- During project initiation , the system’s business value to the organization is identified—how will it lower costs or increase revenues?
- The IS department works to conduct a feasibility analysis. The feasibility analysis examines key aspects of the proposed project:
- ■ The technical feasibility (Can we build it?)
- ■ The economic feasibility (Will it provide business value?)
- ■ The organizational feasibility (If we build it, will it be used?)
- The system request and feasibility analysis are presented to an information systems approval committee (sometimes called a steering committee ), which decides whether the project should be undertaken.
- Once the project is approved, it enters project management.
- During project management, the project manager creates a work plan, staffs the project, and puts techniques in place to help the project team control and direct the project through the entire SDLC.
- The deliverable for project management is a project plan that describes how the project team will go about developing the system
- The analysis phase answers the questions of who will use the system?, what the system will do?, and where and when it will be used?
- During this phase, the project team investigates any current system(s), identifies improvement opportunities, and develops a concept for the new system. This phase has three steps:
- Analysis strategy
- Requirements gathering
- System proposal
- An analysis strategy is developed to guide the project team’s efforts.
- Such a strategy usually includes a study of the current system (called the as-is system ) and its problems, and envisioning ways to design a new system (called the to-be system ).
- The next step is requirements gathering (e.g., through interviews, group work-shops, or questionnaires).
- The analysis of this information leads to the development of a concept for a new system.
- The system concept is then used as a basis to develop a set of business analysis models that describes how the business will operate if the new system were developed.
- The analyses, system concept, and models are combined into a document called the system proposal , which is presented to the project sponsor and other key decision makers (e.g., members of the approval committee) who will decide whether the project should continue to move forward.
- The design phase decides how the system will operate in terms of the hardware, software, and network infrastructure that will be in place; the user interface, forms, and reports that will be used; and the specific programs, databases, and files that will be needed.
- The design phase has four steps:
- Design strategy
- Architecture design
- Database and file specifications
- Program design
- This clarifies whether the system will be developed by the company’s own programmers, whether its development will be outsourced to another firm (usually a consulting firm), or whether the company will buy an existing software package.
- This leads to the development of the basic architecture design for the system that describes the hardware, software, and network infrastructure that will be used.
- The interface design specifies how the users will move through the system (e.g., by navigation methods such as menus and on-screen buttons) and the forms and reports that the system will use.
Database and file specifications
- These define exactly what data will be stored and where they will be stored.
- The analyst team develops the program design, which defines the programs that need to be written and exactly what each program will do.
To sum up…
- This collection of deliverables (architecture design, interface design, database and file specifications, and program design) is the system specification that is used by the programming team for implementation.
- At the end of the design phase, the feasibility analysis and project plan are reexamined and revised, and another decision is made by the project sponsor and approval committee about whether to terminate the project or continue.