BABOK_Guide_v3_member_copy

Data Modelling
Techniques
Attributes can include such values as:
• Name: a unique name for the attribute. Other names used by stakeholders
may be captured as aliases.
• Values/Meanings: a list of acceptable values for the attribute. This may be
expressed as an enumerated list or as a description of allowed formats for
the data (including information such as the number of characters). If the
values are abbreviated this will include an explanation of the meaning.
• Description: the definition of the attribute in the context of the solution.
.3 Relationship or Association
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The relationships between entities provide structure for the data model,
specifically indicating which entities relate to which others and how.
Specifications for a relationship typically indicate the number of minimum and
maximum occurrences allowed on each side of that relationship (for example,
every customer is related to exactly one sales area, while a sales area may be
related to zero, one, or many customers). The term cardinality is used to refer to
the minimum and maximum number of occurrences to which an entity may be
related. Typical cardinality values are zero, one, and many.
The relationship between two entities may be read in either direction, using this
format:
Each occurrence (of this entity) is related to (minimum, maximum) (of this
other entity).
In a class model, the term association is used instead of relationship and
multiplicity is used instead of cardinality.
.4 Diagrams
Both data models and class models may have one or more diagrams that show
entities, attributes, and relationships.
The diagram in a data model is called an entity-relationship diagram (ERD). In a
class model, the diagram is called a class diagram.
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