Let us now focus on an aspect which forms the main topic for the rest of this book–Architectural Quality Attributes.
In a previous section, we discussed how an architecture balances and optimizes stakeholder requirements. We also saw some examples of contradicting stakeholder requirements, which an architect seeks to balance, by choosing an architecture which does the necessary trade-offs.
The term quality attribute has been used to loosely define some of these aspects that an architecture makes trade-offs for. It is now the time to formally define what an Architectural Quality Attribute is:
"A quality attribute is a measurable and testable property of a system which can be used to evaluate the performance of a system ...