Earlier quoted context omitted.
> What is your change request process? I have done everything from formal documentation of changes, requiring pricing and sign-off for every variation, to vaguer schemes. The change request system sucks; it loses sight of why we're building the software and turns into a war of attrition. The issue is always they say the spec is open to interpretation and they meant this, or they expect it to work this way (which is s…
Ya, fair enough. It sounds like you've exhausted the paths that every waterfall developer exhausts before moving on to some kind of agile framework (ex. Scrum). Clients don't like it as much of course, but the we can do is convince them that it fits the way that everyone works better -- nobody knows exactly what they want up front, and if they do, then they're wrong because as soon as they get to use the thing the ne…
I like the idea of a trial period. Get them on-board with low risk to them. As this pattern of working is exactly what I want but can't get clients to do (see my reply to your sibling commenter).
A difficulty is they invariably say the last agency/project did fixed price, so do any others they're talking to, so even if your results are good why aren't you.
They don't feel safe, and it's that safety I need to give back to them.