Look at the Case Study on Page 115 - DO NOT build a proposal - just outline your inital approach to the problem

Include the following items in your discusion: An approach to obtaining a comprehensive set of functional requirements A logically consistent set of qualitative requirements An estimate of constraints An appropriately focused statement of context A logical design process leading to a top-level architecture for the project

Also consider factors that would influence build or buy " Im not sure whether we should build this ourselves or try to find a contractor"

As far as length should be about a page more or less