The very purpose for producing a prototype is to uncover potential problems in the product being prototyped. But what happens when problems you did not anticipate occur in the prototyping process?
Sometimes we need to remind ourselves that the prototyping process by its very nature is a combination of art and science. Generally it is a good idea to allow a little extra time in case everything does not go according to plan. If you have factored a little extra time into your prototyping schedule to account for unexpected difficulties, then there is no stress. But if you are up against a hard deadline and your time allotment is tight, then the stress level does increase substantially. So what are your options when you find out some unexpected issues have arisen that will require extra time and attention?
You can camp out on the prototype supplier’s doorstep and hover over his shoulder, watching every step he makes and asking a million questions. If travel is not an option, then you can call him every couple of hours to find out what he is doing. In either case, anxiety tends to move us to micro-manage in the belief that two heads are better than one, as well as the feeling it gives us that we are doing something actively to fix the problem. That sounds good in theory, but generally is terrible in practice. Nobody likes to be micro-managed, especially not when they have a problem to fix.
Here is a simple solution. Leave your prototyper alone. You gave him the job because you believed in his expertise. The trust was established early on. This is not the time to pull your trust in him. If he indeed is an experienced prototype supplier, he will fix whatever the issue is in order to deliver a prototype to you that is satisfactory. In all honesty, the real test of the worth of your prototype supplier is when a problem arises in the process. So give him the support he asks for and the time he requires to fix the process. The outcome, with or without your hand-wringing and micromanaging will determine whether your faith in his expertise was well placed. As long as your prototype supplier is aware of your ultimate deadline, give him the time and space he needs to solve the issues, and solve them he will.