Quality Assurance (QA) was central to the development of Borland's Quattro Pro for Windows
Context:
A set of roles in a development organization, and a customer, with a need for some filter between them to ensure the quality of the product.
Forces:
Developers feel they get everything right.
Perfect software is hard.
Quality is too often deferred.
Success depends on high quality.
Early feedback is important for fundamental quality problems.
Solution:
The QA organization should be outside the context of the project: the planning and reporting of tests should not be accountable to the development organization.
Resulting Context:
Having engaged QA, the project will be ready to approach the Customer. With QA and the Customer engaged, the quality assurance process can be put in place (use cases gathered, etc.).
Design Rationale:
There are at least reasons for making QA a separate organization from that holding Developers' allegiance. First, test development shouldn't be blind-sided by the Developer perspective. If both the Developer and QA perform their own tests, testing becomes a double-blind experiment with the software as a subject. Second, QA should be put outside the domain of influence by the development organization in the interest of objectivity.
This is an obvious pattern in QPW. See also Application Design is Bounded By Test Design.
Next: Engage Customers