Even in the days of good old-fashioned, unapologetic hierarchical corporations, the job of CEO was never quite as straightforward as it might seem. As the person atop the chain of command, a new CEO might expect to be able to run the company and issue orders as he or she sees fit. This person might imagine that all information will flow through his office, that he is in charge, and that so long as he pleases the shareholders he can do just about anything. Based on their work with CEOs, Porter, Lorsch, and Nohria (PLN) report that new CEOs are likely to be surprised and disappointed, for the reality is quite different.

CEOs are given total responsibility for a company’s success or failure, yet have little or no control over most of the factors relevant to success. Chief executives have more authority than anyone else in the organization, yet cannot wield it without producing undesirable consequences. PLN have found that the seven most common surprises are: You can’t run the company. Giving orders is very costly. It’s hard to know what is really going on. You are always sending a message. You are not the boss. Pleasing shareholders is not the goal. You are still only human. The CEO job is so unique that nothing in a leader’s background is ever full preparation, but PLN draw out some implications for how a new CEO should define his job.

Click the View button above to download a three-page summary of the model (PDF format), complete with a ManyWorlds commentary that discusses the effectiveness of the model.