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 domain language (aka metamodel):

Dimensions and Quality Characteristics

• efficient 37
• flexible 28
• maintainable 18
• operable 40
• reliable 58
• safe 15
• secure 27
• suitable 30
• usable 62

Dimensions and Quality Requirements

• efficient 34
• flexible 16
• maintainable 10
• operable 22
• reliable 46
• safe 14
• secure 18
• suitable 29
• usable 40

Dimensions and Approaches

• efficient 1
• flexible 2
• operable 2
• reliable 2
• usable 2