Why - On any journey, it's wise to know if you really need to take it and why. The same is true for any project. Having a validated problem statement that clarifies to all stakeholders is critical to project change management.What - Based on the "Why", an initial functional and design requirements specification is developed. It is critical that all needs in the "Why" document are reflected in the "What" document(s).When - Based on the "Why" (needs and required availability timing) and the "What" document, the What document is reviewed in the context of make/buy. This begins a negotiation between Need, Time, and Cost. This negotiation may eliminate elements in the "Why" and "What" document.Once the "Why", "What", and "When" elements are harmonized, it's time to develop the How (Design) documents. The How documents incorporate project controls documents, as well as the technical documents. The project control documents (plan, schedule, master document registers, etc. …) are developed early in the project to marshal the technical aspects of "How".Change management of a requirements driven project becomes tenable as there is up-and-down traceability of needs through delivery. Any changes adding or deleting scope of delivery and scope of work will have calculable cost and schedule impact.Understanding the cost and schedule impact before sanction allows both customer and supplier to manage their business fairly.This is a recipe for success.