Tracing
The performance of any workstation can be impacted by the level of tracing it has to perform. The Troubleshooting Guide has a chapter which explains the diagnostic tools that are available, and within that chapter there is a section about the HCL Workload Automation In-flight Tracing utility, which, as well as discussing how the feature works, also describes how to customize it to enhance workstation performance.
The performance might also be impacted by the tracing activities on the WebSphere Application Server.