As companies struggle to meet the challenges of today’s complex business environment by developing short- and long-term strategic visions, the role of chief strategy officer (CSO) has become increasingly prominent. Although CEOs remain ultimately responsible for strategic decisions, they regularly look to the CSO to craft and implement successful strategies. But the role’s relative novelty raises critical questions about its function and the degree of ownership it carries.

McKinsey recently brought together CSOs from several high-profile companies to discuss the challenges of the job—starting with its definition and what it entails. The panel included Edward C. Arditte, senior vice president of strategy and investor relations at the multi-industry company Tyco International; Stuart Grief, vice president of strategy and business development at the aircraft, industrial, and finance group Textron; Marius A. Haas, senior vice president of strategy and corporate development at the technology company HP; Dan Simpson, vice president, office of the chairman, at the cleaning-products group Clorox; Annabel Spring, managing director in charge of strategy and execution at the investment bank Morgan Stanley; and J. F. Van Kerckhove, vice president of corporate strategy at the e-commerce company eBay.

Some of the panelists say that they have one foot in the...