A document written by one person is a temporary project, needing only a little structure to manage the writing tasks. You want to create a writing  plan.

You can use project management (PM) tools for writing management after a quick read of basic planning steps.

To apply PM concepts more broadly, try a short online or face to face course, using your writing plan as an example.

To get started, look at the Action Assessor based on Jerry Seinfeld’s don’t break the chain habit-building method. Remember, the plan is not the work.

The plan is just a tool to help you see where you need to work next.