A Capacity Planning Methodology

a capacity planning procedure called USAGE. Various business elements to be individually measured and tracked are presented. Outlined are methods for estimating workload growth. Separate limits of capacity for on-line workload and batch workload demand are discussed. A simple graphic presentation procedure is included to communicate the results of a study to those who need the information for making business decisions. The crucial problem for installation managers is that of understanding their application and growth environments sufficiently to gain an understanding of the current workload, to forecast the future workload, and to plan future data processing capacity to meet the needs of the business. Although the CPU is not the only resource that requires planning, it is generally the most critical. The methodology discussed in this paper focuses on capacity planning for the CPU. To do this, the current workload is broken down into its most important components, which are called business elements. The business plan is also analyzed, and sources of increased workload and new workload are identified. This information is used to quantify future workload requirements for the planning period of interest. Both current and future CPU capacities are quantified and compared with the workload requirements for the planning period. Separate guidelines are used to track the on-line component of the workload and the total workload requirements. This comparison of CPU capacity and workload requirements allows the data processing manager to have an organized view of the growth of the data processing installation, and to plan for the timely acquisition of new hardware to meet the objectives of the business. We call this methodology Understanding Your Application and Growth Environment (USAGE). Like other management method-ologies, a USAGE capacity plan can be tracked by measuring the Copyright 1980 by International Business Machines Corporation. Copying is permitted without payment of royalty provided that (1) each reproduction is done without alteration and (2) the Journaf reference and IBM copyright notice are included on the first page. The title and abstract may be used without further permission in computer-based and other information-service systems. Permission to republish other excerpts should be obtained from the Editor.