Which of the following is NOT a stage of the Systems Development Life Cycle (SDLC)?

The Systems Development Life Cycle (SDLC) is a structured process used for planning, creating, testing, and deploying information systems. The typical stages of the SDLC include requirements analysis, system design, development (or execution), testing, implementation, and maintenance.

The option that is not a recognized stage of the SDLC is "Execution." While the term "execution" may seem applicable in some contexts, it is not formally used as a stage in the SDLC framework. Instead, the term typically refers to the process of running the finished software or system after the development and testing stages have been completed, but it does not represent a distinct phase within the structured lifecycle.

In contrast, testing, design, and analysis are all essential components of the SDLC. Analysis involves gathering and specifying requirements, design focuses on the architecture and system specifications, and testing ensures that the system functions correctly before deployment. Each of these stages contributes to the successful development of a system, highlighting their importance within the overall framework.