Quality

Quality

Overview

Provides Identity: Yes
Identity Principle: Single
Rigidity: Rigid
Dependency: Mandatory («Characterization»)
Allowed Supertypes: «Category», «Mixin»
Allowed Subtypes: «SubKind», «Role», «Phase»
Forbidden Associations: «ComponentOf», «SubCollectionOf», «MemberOf», «SubQuantityOf», «Derivation»
Abstract: No restriction (default: false)

Definition

A «Quality» is a particular type of intrinsic property which has an structured value. Qualities are things that are existentially dependent on the things they characterize, called their bearers. Types stereotyped as «Quality» are also rigid.

OntoUML differentiates between three types of qualities:

• Perceivable, which capture qualities that could be measured by an agent with the appropriate instrument, like weight, height, color and speed.
• Non-Perceivable, which represent properties which cannot be directly measured by an instrument, like currency.
• Nominal, which are used to make reference to an individual, like one's name, a book's ISBN or a credit card number.

Find in the next figure some examples of qualities:

You can define different types of geometrical structures for a quality value using dimensions and domains. Here is an example:

Constraints

C1: A Quality must always be connected, through a characterization to another type.

C2: The multiplicity of the characterized end (opposite to the quality) must be exactly one. Therefore, the following examples are forbidden.

C3: Qualtities cannot have as ancestors the following types: «Kind», «Quantiy», «Collective», «Subkind», «Role», «RoleMixin», «Phase», «Relator», «Mode».

C4: Qualtities cannot have as descendants the following types: «Kind», «Quantiy», «Collective», «RoleMixin», «Relator», «Mode».