My task was to reproduce an existing machine that this company had built many years before my visit there. For the first time in about a decade, a customer wanted some more of these systems, and the company never really had complete documentation or control over the hundreds or thousands of parts that made up the machines. There were a few ten-year-old drawings for some of the large parts and partial parts lists for a succession of versions.
To make up the difference, someone found some old machines in storage, so we could go measure parts and do some reverse engineering, if we could figure out which features we needed to copy (no two were alike). It turned out, though, that most of the missing information came from a senior technician (I'll call him A.) who had worked at the company for long enough to have assembled the machines in the first place. Long hours and a lack of recognition (real or imagined; I'd guess some of both) had made A. a bit surly and cynical, but a kind word or a bit of friendly commiseration could usually get the answers flowing.
A. remembered when the company had had a machine shop on its premises, along with a full team of machinists and welders. That shop was part of the reason that the machine had been poorly documented: the shop knew how the parts went together and they customized them however they needed to to make them fit. I'd walk down to the shop floor with a parts list or legacy drawing in hand and ask about some part, and A. would tell me why they were all wrong and declare that they weren't doing that anymore. Then he'd usually fish around in his toolbox or some other hiding spot and produce a hand sketch of the correct dimensions, squirreled away since last time anyone had asked. However rough the sketch, it was almost always right. I'd take my notes and measurements and proceed back upstairs and add this "new" information to the model we were building.
There were other things that A. knew that apparently had escaped the notice of the rest of the company, and most particularly anyone in charge. One of these things was how parts actually came in. One part always needed a threaded hole either cleaned out or enlarged (I've forgotten which) every single time it came in. A proper, clear specification for that part would have stipulated that the hole have a clean thread of the correct size, and a receiving inspection should have caught out-of-specification parts and returned them for rework. As it was, A. ended up chasing most or all of these holes with a tap. But that was just one part.
Almost all the parts this company ordered came meticulously cleaned and wrapped in many layers of packaging, a result of the standard drawing notes on all the drawings that did go out. These drawing notes referred to a numbered manufacturing specification, which nobody read before rubber-stamping the standard notes onto every part drawing that went out.
This level of cleanliness is warranted if the part is very high precision and likely to be used in certain sorts of applications, and this company and even this machine included such precision parts. In practice, though, many of their machines were being assembled not in a cleanroom but in a warehouse environment with no air cleanliness controls at all. Many parts also don't need to be cleaned to this degree. A floor mounting bracket will simply get dirty again, and it should never come near the parts that need to stay that clean, anyway. The company, then, was paying extra for the cleaning and packaging, and it was paying more still for an exasperated technician to peel off several layers of unnecessary packaging.
I did ask for and obtain permission to write some simplified drawing notes for parts like the floor brackets, but I doubt anything happened to the standards in the long term.