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Explicitly describe the cardinality of a relationship or an event.
Software engineers care about measurements, both measurements captured by software solutions and measurements of the solutions themselves. As a consequence, software solution designs need to include information about instance populations, including constraints, limits, thresholds, order, storage sizing, etc. So, the description of relationships between instances must consider their cardinality: how many instances of each type participate in a relationship? Definite articles, indefinite articles, and indefinite pronouns offer hints about cardinality. However, where practical, explicit cardinality should be sought for problem descriptions and usage requirements.
Use a limiting adjective when
Limiting adjectives supply (or indicate the need for) quantitative information about subjects and objects, including number, order, degree, etc. Their presence indicates quantitative areas of a conceptual model that should be explored and specified more concretely during object-oriented analysis. Specific numbers that characterize the limitations on relationships should be obtained from the domain experts and solution users. For example, are the relationships
1,
0..1,
0..n,
1..n, or
some other interval?
The following table provides a schema for the kinds of limiting adjectives frequently found in human discourse and the questions that elicit them.
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You can use a clause summary when a limiting adjective appears in statement about an activity or a relationship. You can use a condition description when a limiting adjective appears in a condition.