Fit and Sustainability
Strategic fit among many activities is fundamental not only to competitive advantage but also to the sustainability of that advantage. It is harder for a rival to match an array of interlocked activities than it is merely to imitate a particular sales-force approach, match a process technology, or replicate a set of product features. Positions built on systems of activities are far more sustainable than those built on individual activities.
Consider this simple exercise, The probability that competitors can match any activity is often less than one. The probabilities then quickly compound to make matching the entire system highly unlikely (.9x.9= .8 .9x.9x.9x.9. .66, and so on). Existing companies that try to reposition or straddle will be forced to reconfigure many activities. And even new entrants, though they do not confront the trade-offs facing established rivals, still face formidable barriers to imitation.