Dimensions (also known as tags or labels) are used to structure the fairly large set of quality characteristics. The top-level dimensions overlap by design and are not orthogonal.

Consider an excerpt of our metamodel:

Dimensions and Quality Characteristics

efficient 36 flexible 38 operable 38 reliable 55 safe 15 secure 21 suitable 28 usable 61

Dimensions and Quality Requirements

efficient 32 flexible 13 operable 16 reliable 40 safe 13 secure 13 suitable 25 usable 38

Dimensions and Approaches

efficient 1 reliable 1