The field of strategic planning has stressed, from its inception, that a firm seeking a sustainable competitive advantage should perform both an external analysis and an internal analysis. But after Michael Porter's influential book, Competitive Strategy, appeared, the field seemed to focus on external analysis.

But when I taught strategic planning many years ago, I read some papers by then-UCLA professor Jay B. Barney that pointed out economists believe markets generally price things pretty well. How, then, could buying efficiently-priced assets in the market lead to sustainable competitive advantage? Barney's conclusion was that there was only one way: the firm had to forecast the future value of the assets better than the market. And that's darn hard.

That view led naturally to the one that I taught: both external and internal analyses were important but the firm should focus on finding a sustainable competitive advantage based on internal analysis.

Now I read a brief review of a book written by Mark Hurd, CEO of Hewlett-Packard Compaq, and Lars Nyberg, former chair of NCR, The Value Factor. And what do they write the firm looking for an advantage should focus on? "Capitalize on the information you own about your customers, suppliers and partners; it is the new value proposition for sustainable long-term growth."

The Door: Still Ahead of the Curve (TM).