Rida Elias, assistant professor at the Olayan School of Business, explains what she has discovered by researching top leadership succession in corporations. Too often CEOs, whose work is 75% with people and institutions outside the firm, refuse to leave power. This leads to messy successions, which is why she recommends 4-6-month-long transition periods for CEO changes. COOs, on the other hand, mostly deal with internal issues, where the succession is less complex.