Project Management methods are all about systematic planning, and a structured approach to execution of a project to completion, while writing a book is essentially a creative, unstructured and a meandering activity.
Project management is all about having the project move inexorably towards the deadlines without running into a ‘writer’s block’. Project management has the imponderables from the world working against you, while in writing a book, you are your worst stumbling block ! Once could go on and say a lot about why the twin shall never meet. Thus both the aspects of Project Management Tools and Writing Books are two different things.