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 38 flexible 31 operable 34 reliable 46 safe 11 secure 22 suitable 24 usable 62

Properties and Quality-Requirements

efficient 31 flexible 12 operable 15 reliable 31 safe 7 secure 13 suitable 21 usable 38