Writing · Method
Every consulting model is a bet on when the truth arrives. The fixed-scope model bets it was known at signing. The diagnostic model bets it shows up during the work. Only one of those bets survives contact with a real operation.
A large fixed-scope project fails the same way every time. The scope is written at month zero, the one moment when everyone involved knows the least about the problem. The price is attached to that scope, approval is attached to that price, and from then on the project's incentive is to defend the scope against reality rather than learn from it.
Nobody, including the vendor, fully understands the real constraint until something concrete hits the operation. The fixed contract does not remove that uncertainty. It hides it, and bills for it: change requests, renegotiations, or a delivered system that solves the problem as misunderstood in the sales meeting. Being wrong costs quarters and six figures, and it is the client who pays.
The diagnostic model reverses the order: discover the actual scope first, then price the work that follows. Two weeks inside the operation, at a fixed price, produces three artifacts: a ranked constraint map, an automation and elimination register with effort estimates, and one fully scoped first fix. Delivery then proceeds in two-week sprints, each priced before commitment, each with its deliverable named in writing.
The economics of being wrong change completely. If the diagnostic finds that assumptions were off, that costs days and gets corrected in the next sprint scope. The uncertainty that a fixed contract buries in the price is placed in the structure instead, where it is cheap. The client owns everything produced and can stop after any sprint, which means continuation has to be earned by results rather than secured by contract. The mechanics are described in how the diagnostic works, and what it produced for a legal operation is in the case studies.
A large fixed scope is legitimate when the problem is genuinely known: a migration with a stable specification, a rebuild of a system whose behaviour is documented, compliance work with a fixed definition of done. If the spec will still be true in month four, fixing the price is fair to both sides.
The test is one question: would we write the same scope after two weeks inside the operation? If yes, sign it. If nobody can say, then the scope is a guess with a signature on it, and the honest move is to spend two weeks finding out before spending six months building. When the same question is being asked about a company someone else built, before an acquisition or investment, the equivalent instrument is technical and operational due diligence.
A free 30-minute conversation will tell you whether the scope in front of you is knowledge or a guess. If it is a guess, two weeks of diagnosis is the cheaper way to find out.
Book the conversation →