Old-fashioned integration
A rule engine can become extremely useful when evaluating situations that would become very difficult to determine through a business process, either because the situation is too complex to make a clear diagram out of the sequence of steps required to evaluate the decision, or because the sequence itself is not relevant to the evaluation itself. In the past, adopting the process engine and the rule engine technologies was complicated due to the integration work required to make both engines share the necessary information to operate as expected. As the rule engine and the process engine were completely different applications, communication protocols had to be established between each other. This usually caused a few problems:
Communication protocols between both engines could fail, creating a whole new group of issues that needed to be tested for a specific implementation of our business domain—even if both engines were running in the same environment.
Interaction...