The DEAT Business Rule Pattern Language

Russell R. Hurlbut, Ph.D.

Previous | Table of Contents | Next

Rule Pattern 23: Role

Problem Associating a Real World Entity with a Role

Employees may be assigned a variety of responsibilities within their organization. These responsibilities may be enumerated in a job description for the position they hold. Frequently, informal responsibilities are added that extend beyond the base job description. Other responsibilities may be dropped. Regardless of formal responsibilities, tasks are assigned and work is completed by individuals that would have never been involved if strict adherence to job descriptions was maintained. Delegation of activities must be flexible enough to recognize these informal responsibilities.


Actor role types and organization structure mappings may be created to associate employees or automated support tools with a role. Integrating the adaptive use case user view model with this business rule template provides a concise and powerful approach to completing such mappings. The use cases are specifically constructed to define the system boundary to include all elements that participate in a workflow except for a single actor. Job descriptions may be defined as a set of use cases and constructed for each employee. Through application of the Priority business rule pattern, a ranking of importance may be established.

The assignment of use cases to individual employees only provides a general basis for the actual binding of a use case instance to that individual. Since many employees may play the same role, some criteria must be used to make this determination. The Ordering pattern described how the binding of an actual instance is approached from the role side. Through the application of the Aggregation and Priority patterns, work load balancing and timely handling of activities may be managed.

Example Database Administrator

The position of a database administrator consists of a set of roles defined the collection of use cases. A company employs three people that share this same title. Since all three have identical sets of roles, Ordering and Scheduled Execution business rule patterns are also applied to rotate which one is the primary person on call at any given time. Thus, each is assigned a reference to the ordered collection that contains all employees that share their job description.
Database Administrator Parameters
Employee Job Description Template Collection: <user view adaptive use case>

UML Representation and Related Patterns

The Role business rule pattern maps to Actor model elements that are related to the specified AdaptiveUseCase in the adaptive use case UML extension. The Role pattern may collaborate with the Priority, Aggregation, Ordering, and Scheduled Execution business rule patterns to establish bindings to use case instances.
UML Representation of Role Pattern


Previous | Table of Contents | Next

Copyright 1998 Expertech.Ltd. All Rights Reserved.