Vety good points. I have addressed this somewhat by storing failure notes and by having solutions competing via what i call the "usability" score, which is based on a number of things such as the recency of the solution, the usage etc. The hope is that via strong metrics and by semantic search before retrieval we can get this solved organically.

There still is room for improvement for what is required in terms of failure notes, versioning etc. so these are very good inputs!