11.1. Is Quality Free? The Economic Justification for the Testing Investment
Let's start with economics. There's a really fascinating apparent dichotomy lurking in this topic. On the one hand, improved quality is either usually—or always, depending on whom you ask—a good investment, and this can be demonstrated through a simple model called cost of quality. On the other hand, it is often very difficult to get adequate funding for testing, for reasons both economic and non-economic.
11.1.1. What Does Testing Really Cost?
Nothing. Zilch. Nada. Zero. Quality is free—at least that's what Phillip Crosby wrote in his book of the same name. Frank Gryna did his first cost/benefit analyses on quality at General Electric in 1949. Later, Gryna, together with J. M. Juran, wrote the Quality Control Handbook, which describes a model referred to as cost of quality or quality costs. Crosby, Gryna, and Juran refer primarily to service industries and manufacturing, but recently Sandra Slaughter, David Harter, and Mayuram Krishnan's paper, "Evaluating the Cost of Software Quality," published in the Communications of the ACM, made the same "quality is free" claim for software quality. Likewise, Campenella and his co-authors, in Principles of Quality Costs, include a case study of cost of quality at Raytheon's Electronic Systems group. Raytheon's Electronic Systems group reduced their costs associated with poor quality from a high of over 40 percent of the average project cost to 6 percent over the ...