Dr. Dobb's Journal March 1998
In 1986, Hewlett-Packard's Software Metrics Council identified several categories in which to track faults. In Successful Software Process Improvement (Prentice Hall, 1997), Robert B.Grady summarized this group's findings. Figure 1 illustrates the scheme that grew out of the HP study. Developers use this model by selecting three descriptors for each fault found: the origin of the fault (that is, where the fault was injected in a product), type of fault, and mode (that is, whether information was missing, unclear, wrong, changed, or could be done a better way).
Each Hewlett-Packard division tracks its faults separately, and summary statistics are reported on pie charts like that in Figure 2. Different divisions often have very different fault profiles, and the nature of the profile helps the developers devise requirements, design, code, and test activities that address the particular kinds of faults the division usually sees. The overall effect has been to reduce the number of faults over time.
-- S.L.P.