Commercial software components can dramatically reduce the cost and time required to develop complex business-critical systems. However, integrating them offers stiff challenges that are not well understood by most software practitioners, and there have been many spectacular failures. Now, a team of authors from the Software Engineering Institute draws upon the lessons presented by both the failures and the successes, offering a start-to-finish methodology for integrating commercial components successfully. The authors examine failed integration projects, identifying key lessons and early warning signs, including the failure to account for loss of control over engineering design and production. Drawing upon both successes and failures, they present proven solutions for establishing requirements, evaluating components, creating flexible system designs that incorporate commercial components; and managing multiple concurrent design options linked to external market events and feasibility proofs. They also show how to build "just-in-time" competency with commercial components and integration.