In this chapter, we move up one level in the strategy-making hierarchy, from strategy making in a single-business enterprise to strategy making in a diversified enterprise. Because a diversified company is a collection of individual businesses, the strategy-making task is more complicated. In a one-business company, managers have to come up with a plan for competing successfully in only a single industry environment—the result is what we labeled in Chapter 2 as business strategy (or business level strategy ). But in a diversified company, the strategy-making challenge involves assessing multiple industry environments and developing a set of business strategies, one for each industry arena in which the diversified company operates. And top executives at a diversified company must still go one step further and devise a companywide or corporate strategy for improving the attractiveness and performance of the company's overall business lineup and for making a rational whole out of its diversified collection of individual businesses.