A friend of mine is the inspection department for a custom machine shop. He is also the process engineer and, occasionally, a machine operator. Recently he made his first serious mistake in three years with the company. Naturally he feels terrible; machine shop culture being what it is, he has to endure a period of mild abuse from his supervisors and co-workers. If you work in a shop or have ever worked in a shop, you understand what this entails: teasing, extra supervision, and some scutt work. In these days of Six Sigma and root cause analysis some might think the traditional peer pressure is unnecessary. Would you trust a football coach who didn’t assign penalty laps? I sure wouldn’t. Not to diminish the importance of checks and balances in a processing system and thorough analysis of all defects but personal responsibility is more reliable than group guilt. I’ve been responsible for some monumental screw-ups over the years and tried to learn from each of them. From an organizational standpoint my friend needs to look into how poor work instructions impacted the faulty inspection. A routing item that says only “mill and drill” hardly ensures that every part is completed to print; having the routing writer audit his own work doesn’t help either. Many of my bigger errors came on rush projects where — to “save time” — I checked my own drawings. Bad idea! Another set of eyes is much more effective — and less expensive in the long run. Machine programs need the same type of revision control as drawings. Any time alternate tooling or machines are used there is a greater risk of error. Another contributing factor to my big screw ups was fatigue. No matter how diligent you are, your decision making skills diminish when you work long hours. The tools and the set-ups may remain the same but the maintenance of clamping force, tool sharpness, and coolant flow can deteriorate. Short-cuts on drawing notes or part deburring get forgotten. This is where teamwork comes into play. Peer pressure and teasing are only part of machine shop culture; they only really work in an environment of mutual respect, encouragement, and teaching. If you see someone having a tough time, reach out and help them. Our jobs all depend on satisfied customers and repeat orders.