11.28 Estimating Application Performance by Calculating an ERUF

Given that it is very hard to really test your application's response time on a computer, without using the actual target machine with the real end users signed on and using the system (which is a rather late stage to do such a test), you might find that it is better to apply a "paper estimation" to your critical transactions.

You could base such a test on the following calculation tables, which produce an "ERUF" (Estimated Resource Utilization Factor) for all, or parts of, individual transactions.

An ERUF indicates the type of relative response time you could expect, given the amount work that your function does.

Before attempting to use these ERUF calculation tables, you should be aware of the following:

11.28.1 The Recommended ERUF Ranges are for BUSY Production Machines

11.28.2 ERUF Values are NOT Response Times

11.28.3 Associating ERUF Values With Response Times is a MAJOR Mistake

11.28.4 ERUF Values for Batch Transactions do NOT indicate Elapsed Time

11.28.5 Realistic Estimates are Important

11.28.6 Recommended ERUF Ranges

11.28.7 A High ERUF Value Does Not Mean That Your Transaction Is Invalid

11.28.8 ERUF Calculation Table