The process of gathering a Statement of Requirements (SOR) is key to
successful project management. However, it is also known by many other
terms like, Business Case, Statement of Intent, Scope?
Sites like:
http://www.projectsmart.co.uk/requirements_gathering.html
http://www.idx.com.au/~amilev/Business%20Case.htm
discuss the SOR and give templates.

I want to know, and gather some references as to where the Statement
of Requirements came from, historically speaking and from what basic
knowledge did it evolve?
The eventual outcome of my research would be a model of my own for how
to build a successful SOR for a project in ones own company,
referencing the original knowledge.

I have had problems with this, because it is difficult to cut through
all the different terms used and find how this technique developed.

I sepcifically want references of how this technique was developed,
web links or books / journals would be useful. I do not want templates
or methods of implimenting an SOR.