Designing a successful strategy is also a never-ending quest. Just because companies like Dell or Wal-Mart have superior strategies and are successful today is no guarantee that they will be successful tomorrow. To be successful tomorrow, they will need to develop a strategy that will be superior in tomorrow's market; and to do that, they must understand the underlying principles of their successful strategy of today. Thus, even successful companies need to understand the logic of successful strategies. This is especially so if they arrived at their strategy by means of intuition, trial and error, or luck. It is highly unlikely that the same company will be "lucky" twice. But if its managers understand the principles of successful strategy making, they will be more likely to craft yet another superior strategy once their current strategy has run its course.