The development of a large-scale system or mil/aero platform, be it consumer minivan or combat helicopter, is a long-term project fraught with complexity. The penalties for a miscalculation often manifest as cost overruns, schedule delays, reliability problems, and even dangerous product failures. Every engineer and manager worries about risks like these and takes measures to avoid them. But even in a disciplined and rigorous program, critical issues may not become apparent until the “11th hour” of a project’s life cycle.