The systems development life cycle, or SDLC, is a planning tool used by developers to plan, build and maintain high-quality products. Steps in the SDLC move teams through planning, development, construction and deployment of new software or platforms. Following the SDLC becomes more important for each additional piece of software that the new system interacts or integrates with on the customer's end.
Planning and Analysis
The first steps in the SDLC are conceptual planning and an analysis of the problem that the system aims to solve. Planning covers an estimate of all resource needs and developer costs that will be part of developing the new system. Analysis in the SDLC is the determination of end-user needs and requirements to deploy the new system. During analysis, companies often survey customers about their existing systems and their specific needs to ensure the new system is usable and matches customer capabilities.
Design and Coding
The design phase of the SDLC begins with mapping the proposed data flow, storage needs and processing steps of the system. Initial design usually takes place in charts and processes are verified against goals established during analysis. Developers then begin to code the system itself as well as its user interface. Work can be divided among multiple teams of programmers to speed up the system development. Proper design includes the development and processing of test data to ensure that all parts of the system can speak to each other.
Testing and Integration
Modern SDLC combines testing of the system itself with tests of its ability to work with other platforms and software. On a basic level, this means testing the system or software on the operating system that will run it, such as Linux or Windows. Developers first verify the data flow and processes within the system itself. Next, developers test their new system's ability to communicate with other software a customer may use. Integration testing is first performed on an in-house setup and then on customer systems in rounds of alpha and beta tests.
The deployment phase is when customers receive an approved, working system. The system is officially released and has moved out of all testing phases. For large projects, the creator may offer training programs or integration assistance so customers can begin using the new system. The code itself is not adjusted during deployment unless a major software issue is found.
The final stage of the SDLC is maintenance and feedback gathering. Developers establish a way to communicate with clients about problems or desired improvements for future updates. The maintenance phase is the longest phase because it continues for the full life of the software and guides all improvements and support. Modern systems interact with many pieces of outside software, so the maintenance stage also includes plans to integrate with new systems developed by other companies.