Systems Development Life Cycle (SDLC) - TechTarget

What are the 7 phases of SDLC?

The SDLC consists of multiple phases, with different specialists involved in each. Many phases are interdisciplinary and include personnel from different specialties working together to move the project to the next phase and toward completion.

In general, every SDLC consists of these seven phases:

1. Analysis. The organization evaluates the existing system, identifying deficiencies. This is often done by interviewing users and consulting with support personnel. Management determines whether they require a new IT system to solve a particular problem or address a particular need.
2. Requirements gathering, planning and analysis. Once the new system requirements are defined based on an analysis of the pain points the system means to target, the project manager might then create proposals for addressing the deficiencies in the existing system, outline the development process and set project deadlines and milestones. They will also define other factors required in the new system including features, functions and capabilities.
3. Design. The project team designs the proposed system. The team should consider factors such as physical construction, hardware, operating systems, programming, databases, communications, user interfaces and security. The organization might develop a prototype to show stakeholders what the final product could look like.
4. Development. The project team develops the new system based on the requirements and design that were finalized in the earlier stages. Developers write code using the appropriate programming environment and language. The team obtains and installs new components and programs.
5. Testing. System tests confirm that the system's features work correctly and that it satisfies user expectations. If necessary, the project team makes adjustments to address issues such as bugs, defects, security gaps or other exploitable vulnerabilities. Tests performed by quality assurance (QA) teams can include systems integration, user acceptance testing (UAT) and system testing.
6. Integration and deployment. The new system is incorporated in a production environment and integrated with other systems as required. Deployment can happen in several ways: The new system can be phased in according to application or location, and the old system gradually replaced in a phase-wise manner; however, in some cases, it can be more cost-effective to completely shut down the old system and implement the new system all at once. Users are then trained for the new system.
7. Upkeep and maintenance. This step involves changing and updating the system once in place. An organization upgrades or replaces hardware or software to continuously meet the requirements of end users. Users should be kept up to date concerning any modifications to minimize confusion or productivity losses.

Other steps that often appear in the SDLC include project initiation, functional specifications, detailed specifications, evaluation and end-of-life planning. The number of steps involved in any given SDLC vary depending on the project size, timeline or complexity.

Typically, the more steps defined in an SDLC model, the more granular the stages are. For complex or high-visibility projects, it can be useful to define granular stages -- these can provide early clarity on requirements and expectations and minimize the potential for conflict, confusion or rework.