The problem statement must define a goal and make its achievement seem worthwhile to readers. Readers need to build a mental map of a document so that they can process it efficiently. They need to know if their concepts of what should be included in a document match those of the writer's. If the writer is doing something different that the readers might not expect, the overview is the place where the writer can tell readers which mental map to use in reading the document. 180-184, and pp.
Headers increase the accessibility of a document.
Headers should use the same language as the overview sentence, and they should appear in the same order that they were mentioned in the overview sentence for greater accessibility. The audience should know immediately what each section or segment of the document is about. The audience should have an idea why they are reading this particular section. Find an example of writing that seems too generic in the Proposal. Explain why the example seems generic to you.