Performance management means monitoring and allocating existing data processing resources to applications according to a Service Level Agreement (SLA) or informal service objectives. Capacity planning is the process of planning for sufficient computer capacity in a cost-effective manner to meet the future service needs for all users.
Performance management
- Average transaction response time for network, I/O, processor, or total
- Transaction volumes
- System availability
A fundamental part of performance management is to measure transaction response time and break it down into components. This process shows you where tuning can be carried out for individual transactions. For effective performance management, you need to go on to measure resource requirements at the workload level. Analyzing your workload helps you to understand the behavior of your system and how workloads interact with each other.
Capacity planning
- How much of your computer resources (processor, storage, I/O, network) are being used?
- Which workloads are consuming the resources (workload distribution)?
- What are the expected growth rates?
- When will the demands on current resources affect service levels?
The data that you gather, and the predictions that you make, help you to plan a schedule for upgrading your z Systems™ hardware, or for making additional enhancements such as adding zIIP and zAAP specialty processors to your system.
For more information about capacity planning,
see the IBM Redbooks® publication 
ABCs of z/OS System
Programming, SG24-6327-01.
