A look through HBR’s archives shows that business thinkers use the concept of a “business model” in many different ways, potentially skewing the definition. Many people believe Peter Drucker defined the term in a 1994 article as “assumptions about what a company gets paid for,” but that article never mentions the term business model. Instead, Drucker’s theory of the business was a set of assumptions about what a business will and won’t do, closer to Michael Porter’s definition of strategy. Businesses make assumptions about who their customers and competitors are, as well as about technology and their own strengths and weaknesses.

Magretta carries the idea of assumptions into her focus on business modeling, which encompasses the activities associated with both making and selling something. Alex Osterwalder also builds on Drucker’s concept of assumptions in his “business model canvas,” a way of organizing assumptions so that you can compare business models.