This IBM® RedpaperTM publication shows you how to speed up batch jobs by splitting them into near-identical instances (sometimes referred to as ). It is a practical guide, which is based on the authors' testing experiences with a batch job that is similar to those jobs that are found in customer applications. This guide documents the issues that the team encountered and how the issues were resolved. The final tuned implementation produced better results than the initial traditional implementation. Because job splitting often requires application code changes, this guide includes a description of some aspects of application modernization you might consider if you must modify your application. The authors mirror the intended audience for this paper because they are specialists in IBM DB2®, IBM Tivoli® Workload Scheduler for z/OS®, and z/OS batch performance.