Which Prototype Paperwork Is Worth Paying For

Line up two prototype quotes and the dearer one often carries more paperwork: inspection reports, sign-offs, a formal design review. It is easy to read that as more care. At the prototype stage, it often isn't. Some paperwork protects the test and the money you are spending on it. Some only adds cost to a part whose job is to answer one question and then be set aside.

So which is worth paying for on a prototype? Whatever protects the result of the test: that the part was made to the right drawing, in the right material, with the features the test depends on measured. Anything beyond that should have a reason you can name.

The test I'd use

Ask what each step is for, on this particular part. If someone can say what decision a step protects, keep it. If nobody can, it may not need to be there.

The test works in both directions. It cuts a report nobody will act on. It also keeps a step that looks like overhead but protects you, such as a written scope.

What is usually worth it

• A written scope, so both sides agree on what is being made before anything is cut
• Measurement of the features the test depends on, against your specification
• A certificate of compliance on quality-sensitive work
• Confidentiality under a standard NDA, signed before the detailed conversation
• One job number that follows the work (how one job number supports an R&D tax credit (SR&ED) claim)

Where prototype money leaks

• Cosmetic polish on a part whose only job is to answer a question
• A full report on features the test doesn't depend on
• Sign-offs that repeat a check someone has already made

The middle one deserves a closer look. A full dimensional report measures every feature on the drawing. On a production part, that is how you prove the process. On a prototype testing a snap fit, the useful measurements are the snap, the edge it catches on, and perhaps the wall it flexes. Measuring the rest tells you about features you are likely to change anyway.

The same logic applies to material. If the test depends on the material, as a strength, heat or wear test does, keep the paper trail that shows what the material was. If the test is whether a part sits well in the hand, it probably doesn't need one.

When full process is right

This is where I'd concede the most ground. Regulated work needs its paperwork, and nobody should trim it to save money. If a prototype will be used in a clinical setting, in a regulatory submission, or on equipment a customer will inspect, the rules are set by someone else and the shop's job is to meet them. The same goes for any product heading into production, where the paperwork is how you know the thousandth part matches the first. First article inspection reports are available.

Which rules apply is the client's call, because the client knows where the part is going. A good shop asks before it quotes rather than guessing.

Why it shows up in the price

Every step on a quote is time someone is paid for. On a prototype, those steps can cost more than the part. That is a fair price when the step protects something, and money spent for nothing when it doesn't.

My view is that paperwork on a prototype should be judged the way the prototype is judged: by the question it answers.

Before your next prototype order, read the quote line by line and ask what each item protects.

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