Business Rules

• Succinct statement of constraints on a business process.

• Typically written in text not modeled; however, they influence the structure and flow of models. 

• Establish multiplicities in class models and set criteria for branching in activity models. 

• Stated in short sentences.

• The Object Management Group maintains standards for Semantics of Business Vocabulary and Business Rules (SBVR) since 2008.

• Make modeling business process easier since they limit the number of options allowed by business policy.

Types of Business Rules

• Obligatory: This rule form states what should occur: payment should be made in U.S. dollars. 

• Prohibited: This rule form states what should not occur: no payments by check. 

• Allowed: This rule form says what is allowed under what conditions: credit card payments are allowed if the card is American Express.

Business Rules Enforcement

Rules must be enforceable.

Enforcement levels are:

• Strict enforcement – no violations allowed.

• Pre-override – violations allowed if authorized in advance.

• Post-override – violations allowed if authorized after the violation.

• Guidelines – rules are followed but not enforced.

Decision Tables

Combine multiple business rules to support decisions.

Decision tables consist of:

• Name.

• Set of inputs.

• Set of outputs.

• Set of rules.