Because the WebSphere Application Server versions are different for the latest versions of IBM Business Process Manager V8.5 and IBM Business Monitor V8.0.1.x, it can be a difficult task to augment IBM Business Monitor on an existing IBM Business Process Manager installation. Therefore, it limits the topology options.
Besides, even in IBM Integration Designer V8.5, a model generated in the Monitor Model Editor works without problems except when an artifact, that is bundled with the monitor model application, is developed in the same IBM Integration Designer outside the Monitor Model Editor. For example, when you use user-defined functions and you create the Java project in IBM Integration Designer, at compile and deployment time everything seems to work correctly. However, post-deployment, when the the expressions mappings or gating expressions that employ the user-defined functions are attempted, it fails with a java.lang.NoClassDefFoundError error. This problem happens because, by default, the Java project is created to work with a target Java runtime version of 1.7. For IBM Business Monitor, the version has to be version 1.6.
One of the workarounds for this is to create the UDF Java project with target runtime environment as JRE1.6 instead of 1.7. Then, you can proceed with developing the Java classes with the user-defined functions.