This is one of the thorniest challenges leaders face: stepping into their first role running a whole enterprise. We draw on research and insights from the 2012 HBR article “How Managers Become Leaders,” by Michael Watkins. He’s the author of the seminal leadership book The First 90 Days.

After interviewing executives, leadership mentors, and HR professionals, Watkins identified seven key changes new leaders need to make. Few career transitions are more difficult than leading an enterprise for the first time.

It’s a much bigger job than leading a function—and a lot more complex. Understandably, executives tend to feel overwhelmed and uncertain when they make this big move. To succeed, they have to shift their focus and develop new skills and ways of thinking.

There are seven major transitions to navigate—Watkins calls them seismic shifts. A thorough understanding of each transition can prepare them for success.