Usually you are using BPM endpoint configuration after you extended or modified your topology/environment. For instance, in the case you introduced a web server or load-balancer, you might want to pass all requests through it.
However, beside that you can use BPM endpoint configuration on connection problems for troubleshooting purposes even though no further entry point (web server, load-balancer) is in place. Testing using endpoint configuration might support you quickly by running some tests. With this post I am trying to give you a quick overview (simple topology) on the procedure depending on the BPM version you are using. Hereby, you will find some short details, the command syntax and an example per step.
Note: The concrete steps how to configure your BPM endpoints can be found on KnowledgeCenter (for v857:http://www.ibm.com/support/knowledgecenter/SSFTN5_8.5.7/com.ibm.wbpm.imuc.stbpm.doc/topics/tsec_thirdpartyauthentication_endpointservice.html ).
Hope this helps! n