There are two big challenges with installations: people, and time.
People are the whole point, but people are also really rough on things that are not their own. Particularly the young people who are still learning, and since they are still learning, are the usual target audience for museum installations. So there has to be a lot of both durability and maintainability in an installation piece.
Time is an essential trait for most museums: most have preserving knowledge as a significant part of their mission. Unlike an artifact, as time goes on, an installation is expected to change and stay current with the latest knowledge. Fortunately, it is not usually expected that they will do this without human intervention (Whew!), but this does mean that they need to be fully prepared for upgrades and replacing parts.
Funding is almost always fairly short term for installation development, so they should be cheap to maintain. Further, due to the vagaries of staffing in non-profits, they should not require any particularly esoteric skills to maintain. Assume that at some point in the future, some poor volunteer is going to be called on to determine if "the old
In my next post, I plan to elaborate these thoughts into steps that are a bit more concrete. I hope to see from that if this point of view is particularly supportive of particular design methods, or if it has any surprises about what to emphasize.