A corporate reorganization doesn’t have to create chaos. But many do when there is no clear plan for communicating with employees and other stakeholders early, often, and over an extended period.

Most executives and their employees dread corporate reorganizations, as we can personally attest. During our combined 35 years of advising companies on organizational matters, we’ve had to duck a punch, watch as a manager snapped our computer screen during an argument, and seen individuals burst into tears.

There are many causes of the fear, paranoia, uncertainty, and distraction that seemingly accompany any major reorganization (or “reorg,” a common shorthand for them in many companies). In our experience, though, one of the biggest and most fundamental mistakes companies make is failing to engage people, or at least forgetting to do so early enough in the process.

You need to think about it right from the beginning of your reorg, well ahead of any mass communication. Usually there is one person, a communications manager, who runs the process, and there needs to be a single plan, running like a thread throughout the whole reorg.

In our book, we describe the two traps that leaders typically fall into: wait and see; and ivory tower idealism. We describe three elements of engagement: communicating with employees throughout the reorg; engaging with other stakeholders—unions, customers, suppliers, regulators, and the board; and preparing your reorg team to cope with the challenges of the process. We also explain what to communicate, and how, at each step of the process.

The chart above summarizes how engagement should happen over the course of a reorg.