The idea behind standards is to provide better interoperability between rule/process engines to reduce the time required to learn how to use a new rule engine. We should be able to change the rule engine provider without modifying the application.
As we already know, on the process-side jBPM supports the BPMN standard for process definition and the WH-HumanTask for tasks.
On the rule engine side we have a different situation. There have been attempts to make interoperability easier, for example, JSR94 (Java Rule Engine API) that provides guidelines for rule engine administration and runtime. This standard is supported by Drools, but its value is questionable (it neither standardizes the language used to describe rules nor the execution flow or deployment mechanism), and it will be most likely dropped from Drools in future. There are standards for unifying the rule language, for example, Rule Markup Language (RuleML), which is a markup language developed to express rules in XML or...