Book excerpt: CEOs regularly identify strategic execution as their biggest challenge, and the top priority facing today's business leaders. Based on their research with senior executives across a variety of industries—and including firms like Marriott, Microsoft, SunTrust, UPS, and Vail Resorts—Kenneth J. Carrig and Scott A. Snell have distilled the elements that are most critical for execution. This book addresses the challenges of execution, why it matters, and why the approach remains elusive. It introduces an integrated framework for understanding four priorities underlying execution excellence. Ultimately, it all comes down to alignment, agility, ability, and architecture. The authors lay out a process for applying the framework, helping business leaders to diagnose their challenges and to determine their path toward breakthrough performance.