
Chapter 9 Using Business Rules
Defining business rules in an OOM
You can define a business rule which can be attached to the following objects in an OOM:
Domains
Classes
Interfaces
Attributes
Identifiers
Operations
Associations
Generalizations
Realizations
Dependencies
Types of business rule
In PowerDesigner, you can define several different types of business rules.
Rule type
Definition
Fact
Formula
Validation
Describes
Characteristics or properties of an object in the information system
Certainty or existence in the information system
Calculation employed in the information system
Constraint on a value in the information system
Example
A customer is a person identified by a name and an address
A client may place one or more orders
The total order is the sum of all the order line costs
The sum of the order totals for a given client must not be greater than that client’s allowance