Richard Rumelt is the author of Good Strategy/Bad Strategy: The Difference and Why It Matters.
Strategy as defined by Richard Rumelt
“A good strategy is a coherent mix of policy and action designed to surmount a high-stakes challenge.” Richard Rumelt
“Good strategy has a simple logical structure I call the Kernel. These three elements are (1) a clear-eyed diagnosis of the challenge being faced, (2) an overall guiding policy explaining how the challenge will be met, and (3) a set of coherent actions designed to focus energy and resources.”
KTA: A good strategy is built on the foundation of a good diagnosis.
http://www.anderson.ucla.edu/media-relations/2012/richard-rumelt