asset management - help :-)

I know some of you on this list work for various museums, or have extensive enough collections that a proper asset management system might be needed :-) I've been working on one for the museum here for a while, with the goal of making it easy to add information (so that museum staff aren't tempted to not bother!) and easy to search / browse in a useful way. (Heck knows we need a proper centralised 'list'!) I've pretty much figured out what data's useful to capture, and how a UI might work from the point of view of different user roles (maintenance / administration / browsing etc.) What I'm puzzling over is how to record any relationship between hardware / software / documentation, or even to what extent any relationship needs to be recorded. Thoughts on this would be most appreciated, and I wonder what other museums do... As an example, say we're given a Sinclair machine with some tape software and some manuals. Obviously the machine needs an asset sticker plonked on it and its details stuck in the register. The docs and software also need recording in a DB somewhere such that we know what software we have, and that we have x copies of such-and-such a doc (we'd like to have a public-access library on site, and even lend docs out to trusted people when possible) Question is, do we link the docs and software to that particular machine, or is it better to just put those in essentially isolated databases and recording that they're for such-and-such a model of machine? And what's best for the odds and ends - power supplies, leads, packaging etc.? Do they warrant recording / tagging somehow? And as for what to do with donations of bits I don't know (e.g. when someone gives us a stack of random DEC boards) It gets to be a little more complex than a traditional museum where there's a collection of distinct items - in this case there's a big collection of stuff with a lot of interchangability (if that's a word) between components, and so managing it all is something of a total nightmare! Maybe the idea of knowing exactly what we have at any one time is impossible - but that's a shame if we've got some redundant bit of hardware lurking in storage which we could donate to someone else who desperately needed it to restore a system. Ideas and comments would be *very* much appreciated! cheers Jules