All strategists grapple with the question of how to create and preserve competitive advantage. But individual perspectives are likely to differ, depending on a company’s strategic journey, the industry it’s in, and the idiosyncrasies of the organization. We talked with four current or former senior strategists from diverse corporate environments and markets about their strategic challenges—and came away with four distinct, thought-provoking lists of strategic tests.

Raymond Gilmartin Raymond Gilmartin, a professor at Harvard Business School and a member of the board of directors at General Mills and Microsoft, was the CEO of pharmaceutical company Merck from 1994 until 2005.

Does it violate any strategic laws of gravity?

I have been interested in strategy, both at a conceptual level and as a practitioner, since the late 1960s, when I was studying at the Harvard Business School and the transition was under way from talking about long-range planning to thinking about strategy. At that time, many core conceptual frameworks of strategy were emerging.

Having been exposed to these strategic frameworks early in my career, and believing there were certain principles that one should follow in formulating strategy, a test that I found useful was to look for situations where these principles were violated. For example, if you’ve got a 5 percent market share and somebody else in the industry has 40 percent, the idea that you’re going to make dramatic gains in market share within a relatively short period of time is just unrealistic. Equally unrealistic is wanting to introduce a product that’s undifferentiated and expecting to gain market share just because it’s a big market.