Measuring the Software Process: Statistical Process Control for Software Process Improvement

4 Analyzing Process Behavior

A phenomenon will be said to be controlled when, through the use of past experience, we can predict, at least within limits, how the phenomenon may be expected to vary in the future. Here it is understood that prediction within limits means that we can state, at least approximately, the probability that the observed phenomenon will fall within the given limits.

Walter A. Shewhart 1931

In this chapter, as well as Chapters 5 and 6, we will address the principles that are the basis for quantifying and analyzing process behavior as shown in Figure 4.1. The discussion in this chapter leads to the introduction of Shewhart’s control charts as an operational definition of process behavior in terms of process performance, ...