Odds are, you are trying to find ways to manage and merge metadata structure from one or many different legacy systems into a unified structure in your new DAM system. One of the major problems can be dealing with the exceptions and most importantly not letting them command more attention or effort than they merit. George Carlin had an old bit about catholic school students trying to find chinks in the armor around the rules of eating meat on Fridays…by the end of the joke, students are outlining all sorts of crazy scenarios including one that has them on a boat, on the pacific, about to cross the international date line and trying to figure out what to do.
The point is that THERE ARE ALWAYS GOING TO BE EXCEPTIONS. Be at peace with this reality and then move on. The focus should be designing a metadata structure and strategy that can effectively address the RULES and have the capacity to manage, support and attend to the EXCEPTIONS.
This is almost a mantra and something that you need to continually remind yourself of throughout the design process in order to remain on track. It’s just too easy and frankly too human to get sidetracked into the weeds on a major tangent because someone or some group involved in the discussion has proclaimed the need of the exception paramount.
Ask yourself, is this something that most users will need and if so how often? What are the risks of moving away from this? Will this be available in some way and be searchable? Will there be the capacity within the new structure to address most of the need going forward? Will there be a new way to retrieve the exception info in different way? Remember, you DAM isn’t a digital replica of your old systems and workflow…there may be new ways to service less common needs or they may be usurped by the way the new tools deliver and report on their assets and data.
Design and create support for the rules, build in the capacity for the exceptions and make everything flexible enough to evolve as things change…and trust me, they will.