Most academics will admit to themselves and students that the majority of dissertations and books are written in a 6 month block of time (the remainder of the post focuses on a PhD process, but it can be easily applied to book writing). I'm talking here about the WRITING process- not the research, figuring out the question, organizing the chapters etc (no wizard can do all that in 6 months- at least not this wizard). But once you've done your (field) research, reading, thinking through the chapters, taking notes etc. it really should only take you 6 months to finish the thesis. For PhD...