Operational Analysis Revisited: Error Measure Limits of Assumptions

Abstract

The assumptions used to develop operational analysis
computer performance measures, such as number of jobs at a
device or response times, are stated in terms of the data itself,
rather than the underlying system which produces the data. In
spite of claims of validity and as an aid in introducing queueing
theory in teaching, little has been written about operational
analysis in the past ten years. Accuracy of operational analysis
performance measures depend on data behavior assumptions
which can be validated with data based error measures.
Increased soundness of the operational analysis approach may be
obtained by determining the limits of assumption errors as the
time period of observation increases. Part I of this paper is a
review of operational analysis and addresses some of the previous
concerns with its approach. Part II develops further
understanding of operational analysis assumption errors by
examining their limits. Limits are found for the assumption
errors of job flow balance, homogeneous arrivals and
homogenous services. While the job flow balance assumption
error measure is shown to approach zero over time, the
homogeneity assumption error measures, in general, do not.