IBM® z/OS® Debugger Utilities: IMS TM Debugging
You can create private IMS message regions to debug test applications without interfering with other regions. Use the IMS Transaction Isolation function to view a list of IMS transactions for Message Processing Regions in an IMS system, and select the ones that you want to debug. You can also use this function to clone a transaction's operating environment into a private message-processing region that is reserved for your use. Any transactions that you register to debug are routed to this private environment to isolate you from other users of that same transaction and environment.
For IMSplex users, you can modify the Language Environment® runtime parameters table without relinking the applications. The tools that can help you complete these tasks are found under option 4, called IMS TM Debugging.