I see this 1996 Harvard Business Review-article as an reply to all the critics of his frameworks and models (such as Henry Mintzberg and Gary Hamel). In his reply, Michael Porter discusses operational effectiveness in relation with strategic positioning. The author does this through explaining the difference between operational effectiveness and strategy ("It is necessary but not sufficient"), strategic positioning ("Competitive strategy is about being different."), strategic trade-offs ("The essence of strategy is what NOT to do."), strategic fit ("The success of a strategy depends on doing many things well - not just a few - and integrating among them."), and rediscovering strategy ("Although external changes can be the problem, the greater threat to strategy often comes from within.") Michael Porter concludes that both operational effectiveness and strategy are essential, but that the two have different agendas. Managers need to be aware that there is a difference between the famous management tools/fads (TQM, benchmarking, BPR, etc.) and strategy formulation. Just aiming for operational effectiveness often results in lower industry profits - so everyone loses out. The final point that the author makes to his critics is that "strategic continuity does not imply a static view of competition. Strategic continuity, in fact, should make an organization's continual improvement more effective."
I did enjoy this Harvard Business Review-article a great deal since it responds to comments from various critics. It also allows a comparison with other academics and business writers in the field of strategic management. I recommend it to managers and, certainly, all MBA/Business-students. The author uses simple US-English.
It is, however, available on the internet in PDF format. Search Google.