Improving the performance of a CICS system

Tuning is a key factor in improving the performance of a CICS® system. You must always tune DASD, the network, and the overall MVS™ system before tuning any individual CICS subsystem through CICS parameters. Before you tune a system, you must understand why your CICS system is not performing as expected.

If you have concerns about the performance of your CICS system, use the performance flow diagram as a guide to understand why your CICS system is not performing as expected, and as a guide to solve the system problems.

For example, if you determine that response times in your system are too slow, view your CICS Performance Analyzer (CICS PA) reports and the performance summary. Use the performance summary and the performance analyzer report to determine whether it is the dispatch time or the suspend time of tasks that is greater. If the suspend time is greater, determine whether the dispatch wait time is low or high. If the dispatch wait time is low, use information in reports to help you improve the performance.

To help you improve performance, you can view tuning guidelines for different aspects of CICS: