Investigation into Scheduling for an Interactive Computing System

Abstract

This paper describes a statistical evaluation of the performance of the swap scheduling algorithm of an interactive computer system and an investigation into foreground-background scheduling to improve system performance. Input traffic. computer service time demands. and system performance were statistically analyzed. Based on the results of these analyses performance enhancements for the system were determined and then evaluated through use of a validated simulation model.

Verifying and validating simulation models

“…Examples of a histogram and a box plot are given in Figures 3 and 4, respectively; both taken from Lowery (1996). Examples of behavior graphs, taken from Anderson and Sargent (1974), are given in Figures 5 and 6. A variety of graphs are required that use different types of (1) measures such as the mean, variance, maximum, distribution, and times series of the variables, and (2) relationships between (a) two measures of a single variable (see Figure 5) and (b) measures of two variables (see Figure 6).…”

“…It is important that appropriate measures and relationships be used in validating a simulation model and that they be determined with respect to the model's intended purpose. See Anderson and Sargent (1974) and Lowery (1996) for other examples of sets of graphs used in the validation of simulation models. These graphs can be used in model validation in different ways.…”

Verification and validation of simulation models

“…(See Sargent (1996aSargent ( , 2001b Lowery (1996). Examples of behavior graphs, taken from Anderson and Sargent (1974), are given in Figures 6 and 7. A variety of graphs are required that use different types of (1) measures such as the mean, variance, maximum, distribution, and times series of the variables, and (2) relationships between (a) two measures of a single variable (see Figure 6) and (b) measures of two variables (see Figure 7).…”

“…It is important that appropriate measures and relationships be used in validating a simulation model and that they be determined with respect to the model's intended purpose. See Anderson and Sargent (1974) and Lowery (1996) for examples of sets of graphs used in the validation of two different simulation models. …”

Some subjective validation methods using graphical displays of data

“…To illustrate behavior graphs, we consider a simulation model of an interactive computer system in Anderson and Sargent (1974) where behavior graphs were used to validate the model. Three behavior graphs they used are presented in Figures 8, 9 and 10.…”