At the most basic level, leadership succession and transition is a continuous process of organizational transformation: a people decision, an organizational decision, and a strategy decision all rolled into one, with not infrequently a crisis call thrown in for good measure, according to Noel Tichy in his book Succession: Mastering the Make-or-Break Process of Leadership Transition. Leadership succession and transition is simply the most politically and culturally charged, technically challenging, and critical leadership assignment of all the many judgments that business leaders are obliged to make in the course of doing their day jobs.
My full review of the book is available at my business book reviews website.