Conclusion
Vital business rules are increasingly enforced by object-oriented software, but methodologies for mapping business rules to objects do not exist. A business rules methodology should do the following: (1) encapsulate rules in the objects they govern; (2) use proactive rule checking to enforce rules during change; (3) include strategies for distributing the work among objects. This article introduces a pattern-based rules methodology that includes proactive rules checking, a categorization scheme for business rules, and strategies for mapping business rules to patterns.