You can configure Rule Execution Server so that it is scoped to a single Java EE application.
In this use case, Rule Execution Server is scoped exclusively to a single application. The Execution Unit (XU) is deployed within a single application. With this deployment option, you can deploy multiple applications to the same server.
If you package the Rule Execution Server XU resource archive (RAR) file in your enterprise application (EAR), applications that use a previous version of WebSphere® Operational Decision Management or multiple applications that use the current version of WebSphere Operational Decision Management, or both, can coexist in the same Java Virtual Machine (JVM).