Michael E. Porter’s Competitive Strategy has transformed the theory,practice,and teaching of business strategy throughout the world. Electrifying in its simplicity —like all great breakthroughs —Porter’s analysis of industries captures the complexity of industry competition in five underlying forces. Porter introduces one of the most powerful competitive tools yet developed:his three generic strategies —lowest cost,differentiation,and focus —which bring structure to the task of strategic positioning. He shows how competitive advantage can be defined in terms of relative cost and relative prices,thus linking it directly to profitability,and presents a whole new perspective on how profit is created and divided. In the almost two decades since publication,Porter’s framework for predicting competitor behavior has transformed the way in which companies look at their rivals and has given rise to the new discipline of competitor assessment.