3.5 Concluding Remarks
Chapter 2 described the various types of performance models from a qualitative point of view. In this chapter, these models are quantified. A set of very important relationships between performance variables is introduced. These relationships, called Operational Laws, are quite general (i.e., robust) and are extremely useful because: i) they are very simple, ii) they are based on readily available measurement data, and iii) they can be used to obtain helpful performance metrics.
Simple bounding techniques were introduced and used to obtain upper bounds on throughput and lower bounds on response time from service demands. Examples were presented of applying QN models to various performance situations. In the following chapters of Part I the set of applications of performance models is expanded. The models used here are described in Part II and are implemented using the tools included.