A declarative rule is an instance of a subclass of the Rule-Declare-class.

In a Declare Expression, Constraints, Declare On Change, or Declare Trigger rule, we can specify needed relationships among attributes. When the value of a property is involved in any of these declarative rules, the system checks an internal dependency network for other values that are affected and does other processing based on the network's configuration. This is referred to as Forward chaining.

Most declarative rules are reevaluated after the following types of events:

• When USERS upload an input form, it is evaluated at the end of the input processing.
• During the execution of an activity, assessment takes place at each step, after the method has completed but before the evaluation of a transition in that phase.
• As CONTROL passes from one job (one shape on the Visio flow diagram) to the next during flow execution.
• When the work item progresses from one form to another and WITHIN connectors at the end of a flow transition (if a relevant property is set).
• When the value of any of the attributes involved in the rule changes, index rules are activated.
• When an OBJECT is saved to the DATABASE, trigger rules are activated.

Decision tree rules, decision table rules, and case match rules do not employ forward chaining and are only assessed when explicitly requested.