Separate constraints and preferences
List rules that must hold, such as fixture capacity and prohibited adjacencies, separately from preferences such as visual grouping. Define what should happen when two requirements conflict and who can approve an exception.
Describe each rule consistently
For each rule, record its scope, required input data, condition, expected outcome, and owner. Include one valid and one invalid example. Confirm how the agreed rules will be represented in your implementation instead of assuming a particular configuration interface.
Test against real variations
Review a small store, a large store, and a location with unusual stock or fixtures. Check infeasible cases as well as successful ones. Keep a revision history and reassess rules when the product range or facility changes.