I believe that the validation and verification steps are done throughout the process. The 9 design controls are ideal and the general layout of how a project should go. Unfortunately, sometimes after testing, unforeseen problems are discovered. Verification and validation is the first time you are actually testing this idea and in validation testing, one might realize that the user inputs in practice, contradict an input specification that was just previously verified. One will submit a change request and appear to be at that step but in reality you are going back to the input stage.