The business school professor and executive Michael Porter is often associated with the concept of value-based healthcare after releasing a book in 2006 with Elizabeth Olmsted Teisberg on the topic. However, Porter is more often associated with his famous 'Five ______' of business strategy. What word fill's the blank?

Fact: There are nearly 28 million small businesses in America. Of those 28 million, a full 22 million consists of one lone employee.