I agree that what you are saying is useful, i.e. identify the minimal sets of contradicting constraints, but if you can relax a constraint, then you are effecti

I agree that what you are saying is useful, i.e. identify the minimal sets of contradicting constraints, but if you can relax a constraint, then you are effectively solving a different problem. OTOH it's pretty well known that customers mostly don't know what they want, so deciding what is actually a constraint and what isn't is, paradoxically, a part of the job.