Before you scope the work,
make the mandate testable.

Deliverables can all land while nothing changes. Conditions can be tested against reality.

Rewrite the mandate as conditions: "X is true" rather than "we will build X".

If they do not agree now, they will disagree later at higher cost and with less goodwill.

Ask each sponsor separately to write the mandate in two sentences, then compare.

A mandate without a named unit of work applies to everything, which means it governs nothing.

Name the lifecycle or work type the mandate covers, and what it excludes.

Locking a solution into the mandate removes the ability to change approach without renegotiating the mandate.

Split the mandate into conditions and current chosen approach. Keep them in separate columns.

Cross-functional conditions owned below the seam cannot be enforced across it.

For each cross-functional condition, name an owner senior to every function it touches.

Most transformations require changing who decides. Without that authority the work stalls politely.

State who can change decision rights, and get it confirmed in writing.

A milestone proves a date passed. A state proves something is different.

Replace each milestone with the state it is supposed to produce, plus how it will be proven.

Unwritten scope boundaries get relitigated every time capacity gets tight.

Write the out-of-scope list and have the sponsors sign the same version.

If it needs context to make sense, it will not survive the organization reading it.

Give the mandate to someone uninvolved and ask them what it requires. Rewrite until they are right.