Properties (also known as tags or labels) are used to structure the fairly large set of qualities.

Consider an excerpt of our metamodel:

Properties and Qualities

efficient 39 flexible 37 operable 39 reliable 57 safe 15 secure 23 suitable 27 usable 65

Properties and Quality-Requirements

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