The following figure shows pictorially how test documents span across the software development lifecycle. The following discusses the specific testing documents in the lifecycle:
Software Testing Image
Central/Project test plan: This is the main test plan which outlines the complete test strategy of the software project. This document should be prepared before the start of the project and is used until the end of the software development lifecycle.
Acceptance test plan: This test plan is normally prepared with the end customer. This document commences during the requirement phase and is completed at final delivery.
System test plan: This test plan starts during the design phase and proceeds until the end of the project.
Integration and unit test plan: Both of these test plans start during the execution phase and continue until the final delivery.