Four reasons to write a specification

In “Writing the Ultimate Machine Vision Specification” (Visiononline, July 13^th, 2012,) Winn Hardin explores the importance of a written specification. There’s discussion of the importance of defect samples, sensible quotes from machine vision gurus, and suggestions about capturing images on the line, but precious little about the benefits. So I thought I’d come up with some.

Here’s why I believe it’s very important to write a specification for your machine vision system:

1. It tells the integrator bidding on the job what he has to do to get paid. To be fair, you should include how you will test the system and what performance you expect to see. Even if you end up doing the work in-house, it’s still very important to understand exactly what the system is supposed to do.

2. It lets you, the buyer, compare quotes on an apples-to-apples basis. How else will you know what constitutes value-for-money?

3. If you don’t provide one, a good integrator will have to write it. That costs him time and money which, one way or another, will end up in the price of the system. A less professional integrator might skip this step. That would let him submit a lower bid, and if your Purchasing Manager is like mine, you’ll be obliged to take it, even though you know it’s the wrong thing to do.

4. When the job is complete – or you’re arguing about whether or not it’s complete – the specification is the document you dig out and compare against what was delivered. (This is however where your Purchasing professionals earn their keep. They need to ensure that it’s your specification that forms part of the legally binding contract and not integrators quote. Not heeding this point can result in the integrator saying, “I built exactly what I quoted, so pay me,” even if you didn’t get what you wanted.)
   

Motherhood and apple pie? Sure it is, but people are busy, the boss wants results, and sometimes it’s easier to just make a call and trust that your integrator understood all your arm-waving explanations and descriptions.

Let me finish with one last tip. When you’ve taken the time to write a specification, be sure to put as much effort in to reviewing the proposals you get back. Admittedly, they never read like a Stephen King page-turner, but it’s important to check every line and understand every nuance. Miss a detail and it might be your job on the line!