Comment Blurred roles here (Score 1) 324
I think your difficulty is that your current work flow obfuscates two roles. You are using your Stakeholders (the users of your software) as the individuals in charge of acceptance. They're likely not motivated, or possibly not qualified, to do so really. Remember they're just interested in getting THEIR work done. If their workflow were "enlightened" like yours, then they might care about process... but probably not.
The missing piece of the puzzle here is the role of Product Owner. An individual that works with your team in close proximity that prioritizes your work and helps you determine what the acceptance criteria are before you start. Your work is not done until that person accepts the work according to the criteria.