Capacity Planning using EPV for z/OS

Fabio M. Ottaviani
September 2004

From the various disciplines of Capacity Management, Capacity Planning has always been the most unloved. All companies manage Service Levels in different ways, and consequently the performance of their systems and applications; most of them have Cost Accounting and Chargeback procedures, but only some of them have a specific Capacity Planning activity running regularly.

The major reasons for this situation are the following:
• Capacity Planning is the only Capacity Management discipline that doesn’t attain only to the past and present, but also to the future of systems and applications;
• even when based on metrics and methodologies, the forecast of something that will happen in the future is often affected by significant errors ;
• the accuracy of the result is highly dependent on the skill and experience of those that make the plan; these skills are difficult to find and very expensive;
• specific tools for Capacity Planning are generally very expensive too, and not really user friendly;
• Capacity Planning projects require long periods of time before some result can be produced.

Even with all these difficulties, Capacity Planning activities are always in someway performed, also in those organisations where there isn’t a specific group responsible for the discipline, by:
• system programmers, based on their judgement on critical issues to come and avoid (more often already existing);
• managers, with respect to their budget;
• vendors, sometimes more keen to their own goals and objectives.

The systems programmers approach could be the most valid from the technical point of view, but not really effective because it’s a based on a reactive approach and on the analysis of sporadically collected data.

In the following we will introduce a cost effective Capacity Planning methodology that is designed to guide the user to perform rapid Capacity Planning studies, reducing forecasting errors and solving most of the problems mentioned above.