In my opinion, I believe verification can occur at any phase during a project. It all depends on the kind of project and especially in medical devices, verification is a must step after each operation during manufacturing. Verification can also occur after the project manager creates the Bill of Materials (BOM) and checks to make sure all the parts/ assembly parts have been ordered to manufacture the device. All in all, it is not a rigid rule and verification can occur at any time during the project. It can be in the beginning after planning or in the end, right before shipping the device to the customer.