We are trying to introduce some agile concepts to the business folks but one of our biggest hurdles is their expectations for documentation - the quantity, the authorship/ownership of the documents, the lifecycle of the documents, the timing of the authorship, and the material that should be documented. The business folks are very much in a traditional mindset. For them, documentation is a risk management tool.
What can we do to help them view documentation as a risk and a requirement? We've tried indicating in the project timelines how much extra time is spent on documentation. Their response is it helps them estimate project costs and reduces risk. We respond with empirical evidence showing it hasn't worked to date. They respond with "that's IT's fault for reasons x, y, z" and then introduce more documentation to account for IT's failings. And then it spirals on and on until the baggage is un-bearable.
Regarding authorship, we've tried to convince the business that IT doesn't want or need certain documents and that the business is capable of producing them without IT if they feel it's needed. So they will produce something, and then hold us accountable for its contents even though it is (from our perspective) un-related to us and un-vetted by us. So when we try to vet their documents, we get sucked in and then the questions of ownership and maintenance rear their ugly heads.
From everything I've read, this is a no-win situation. Is there any advice or thoughts to help us transform their expectations of documentation to light-weight, just-in-time/just good enough documents?
If needed, find more background in my previous question.