I would say that the risk of verification and validation is not completing it in the time constraint you had originally planned or not being able to complete it at all and having a project cancelled. They are both lengthy processes as you can see in the two flow charts. On the flow chart for verification you won’t know if you need to go back to almost the beginning until the end of the chart. It might be necessary to go back and revise more than once. Delays may cause issues but verification and validation are needed to ensure that the design inputs equal the output and that the inputs satisfy the user needs and what the intended use is. You want to make sure that all your testing is thorough and that each input is met so hopefully you can move on to the next step as scheduled.