Interpretation of the modelThe first thing we should be clear about is that these are all just assumptions.
Since they are assumptions, it's good to clarify that both client and service provider have the same understanding of these assumptions beforehand, since they define expectations.
These assumptions are not axioms, since each variable can be verified objectively by asking questions and observation. Neither client nor service provider should turn any of these assumptions into dogma and insist they be true regardless of reality. You must accept that any of them may turn out invalid at any time.