As Betty explained the tasks needed to be performed by the PM to obtain accurate assessment of quality assurance of the project. To add to the next step, I would say that executing process, design verification and validation are where time management really kicks in. Everything is planned prior to that but this is where the PM actually needs to stick to the timeline for the project and make sure everything required is provided to the team members. This will avoid any delays or missing of milestones. Another important aspect is to make sure everything is on point so that no changes would be needed after design verification and validation. This also causes a delay in the project.