Readers of Cheryl Watson’s Tuning Letter will be familiar with Alain Maneville, from IBM France. Alain co-wrote an article about HiperDispatch for the Tuning Letter, and is also the author of the LPAR Design tool. The LPAR Design tool allows you to enter your LPAR configuration and model the impact that changes in an LPAR’s weight or its number of engines will have on the CPC HiperDispatch topology. We highly recommend the use of this tool if you want to optimize your HiperDispatch topology. The tool is available for download from http://www-03.ibm.com/systems/z/os/zos/features/wlm/WLM_Further_Info_Tools.html#Design. Alain recently updated the tool to version 8.1, adding support for z13s, the latest level of zPCR (8.8a), and other smaller enhancements. If you use Alain’s tool, we recommend that you always download the latest version before running it.