Which of the following is not a phase in the software development lifecycle?

The software development lifecycle (SDLC) consists of several well-defined phases that guide the development process from initial concept through to delivery and maintenance of the software. The typical phases include planning, designing, developing, testing, deployment, and maintenance.

In this context, planning involves defining the project scope and resources needed, designing covers creating the software architecture and interface layouts, and deployment is the phase where the software is released to users after it has been built and tested.

The phase referred to as "executing" does not align with the established terms used in the SDLC. While execution of plans and designs does happen during the development phase, it is not a standalone phase in the lifecycle. Therefore, it is not recognized as one of the core components of the software development lifecycle.