Megaprojects require investment of $1bn or more to build infrastructure, usually involving a complex system of production consisting of discrete, routine, and high-volume repetitive processes. Many of these processes can be progressively standardized and replicated to improve overall productive performance. This article presents the findings of research on design and production of London’s Heathrow Airport Terminal 5 (T5). The findings were used to develop a conceptual framework--which we call the systems integration model--to identify the project and operational processes that contribute to success in delivering megaprojects. The systems integrator is the lead organization in a megaproject, responsible for establishing a governance structure, managing risk, and coordinating processes performed by a large network of external suppliers. Innovations based on the "recombination" and "replication" of processes can be introduced to improve megaproject performance.