Risk and retention: learning from Heathrow Terminal 5 for defence procurement

eak commercial discipline. This article argues that the deeper problem is the gap between retained and governable risk. The article uses Heathrow Terminal 5 and Project 13; an infrastructure enterprise-delivery model, as prompts rather than templates. It develops Ajax as the main defence case and the Queen Elizabeth-class aircraft carriers as a secondary strategic-lock-in case. The contribution is a defence capability owner framework that Defence Equipment and Support (DE&S) can use as a diagnostic tool before commitment, during delivery and after programme review. The framework places learning capability at the centre because long-duration defence programmes repeatedly convert weak continuity, poor issue escalation, and thin institutional memory into ungovernable retained risk. The article contributes to the strong-owner and defence-procurement literatures by making the retained/ governable distinction operational, translating it into a five- capability diagnostic usable by DE&S.