Using a unique number when we are asked for a document it will be easier to search through files that are sorted in a unique number order. The alternative of wading through numerous calibration instructions searching for an equipment name alphbetically doesn't sound like the best option
When you say 'when we are asked for a document', who asks you? And when? And do they ask because they can't find it? etc. (It's impossible to discuss document systems without understanding when, why and how docs are used). I do understand (to some extent) the need for numbers if there are a very large number of documents.
It's just that I remain unconvinced that numbering in all cases, as a bog standard approach, is a Good Thing - indeed, rather the reverse. I really haven't seen anything much in this thread that has made logical and powerful points in favour of numbering. In fact, good, logical and sound reasons are notable by their absence. Instead, there's a strong tendency to quote others/say 'lots of other people do it' (the old 'everyone else does it' argument).
I have also purchased a number of books and one in particular advocates a numbering/letter sytem as documentation can usually be cross referenced to product and product to multiple documents such as drawings, material lists, change controls etc.
Yes, I know some books advocate it. But um, so what? Just 'cos it's in a book doesn't mean it's right. The mere fact that some one says 'this should be done' is not, to me, a good argument! I always look for good reasons - and I'm still waiting for any to be advanced in this thread. And a cryptic 'easier to manage/index' doesn't do it for me.
Like Andy, I believe people recognise things by name, by look, etc... not by number. OK, I know that will horrify the strictly engineering/scientific among you who love things listed as QFD-005-03 Document Title Here... but I have never yet (never!) come across such a system that anyone other than the architect & maybe the odd document controller actually understood, let alone used.
I spent literally years as a consultant in streamlining/setting up/revising/redesigning document systems, document management systems etc, both online and hardcopy... And I fully understand that unique numbers are essential in a database. I also do agree that in a
very large system dealing with thousands of documents, that numbers are almost certainly going to be needed. But they don't have to HIT YOU IN THE FACE BEFORE THE TITLE either. The ISBN system works fine - but it isn't built into the title of ANY book in the world. It's available... but not the first thing you see.
But I do favour systems that are practical, flexible (eg, offer more than one way to locate a document), and designed to suit the particular context and the way people's brains actually work (rather than how people think things ought to be numbered).