The chapter brings together theoretical foundations and research findings as well as effective coaching methods from the preceding chapters into an integrative theory. The main assumptions about the effects and interactions of general success factors in the coaching process are depicted in a model. They are then explained one-by-one. Readers are thus provided with a summarized overall picture of the status of the diverse, scientifically based findings on the performance of coaching, which, according to scientific findings, lead to practical results. The theory is a framework that is open to change and invites the reader to revise or expand it.