Total Quality Management

"TQM is a set of systematic activities carried out by the entire organization to effectively and efficiently achieve company objectives so as to provide products and services with a level of quality that satisfies customers, at the appropriate time and price.

" It is important to record not just the measurement ranges, but what failures caused them to be chosen. In that way, cheaper fixes can be substituted later (say, when the product is redesigned) with no loss of quality. After TQM has been in use, it's very common for parts to be redesigned so that critical measurements either cease to exist, or become much wider.

It took people a while to develop tests to find emergent problems. One popular test is a "life test" in which the sample product is operated until a part fails. Another popular test is called "shake and bake", in which the product is mounted on a vibrator in an environmental oven, and operated at progressively more extreme vibration and temperatures until something fails. The failure is then isolated and engineers design an improvement.

A commonly-discovered failure is for the product to disintegrate. If fasteners fail, the improvements might be to use measured-tension nutdrivers to ensure that screws don't come off, or improved adhesives to ensure that parts remain glued.