Evaluation of Rule Collections

We had a look at how Aware IM identifies instances of the business objects to work with and also what happens when actions are executed. Let us now look in more detail at how rules are evaluated. In the Rule Evaluation section we have provided the list of events that trigger rule evaluation. When any of these events occur there is a number of rules that are considered for evaluation – if a process has been started these are the rules that implement the process, if an instance of a business object is created or modified, these are the rules attached to the business object and so on. We will call these sets of rules rule collections.

Rule collections can be ordered or un-ordered. Ordered rule collections are evaluated one-by-one in exactly the same order that they appear in the rule collection. The only example of an ordered rule collection is a process implemented by rules, which has the “Maintain rule order” flag turned on – see Adding/Editing Processes. When such a process is started its first rule is evaluated and the actions are executed if rule conditions are met. If actions create any instances of the business objects they are placed in the Context as described in the Context section. If actions create or modify instances of business objects the rules attached to these business objects (if there are any) are evaluated, cross-reference rules (if there are any) get evaluated as well – as described in Action Execution. When action(s) of the first rule finish their execution, the second rule of the ordered rule collection of the process is examined – its conditions are evaluated and if they are met the corresponding actions are executed. This cycle is repeated until the last rule in the collection has been evaluated.

Evaluation of un-ordered rule collection is very different. So different in fact that an entire section in this document is dedicated to the evaluation of un-ordered rule collections. See Evaluation of Unordered Rule Collections.