Software error classification using Purify

Perfect quality represents 100% conformance to specifications. Complex systems make it difficult and expensive to assure conformance to specifications by post-production testing alone. As a result, quality assurance processes are moving upstream in the life-cycle, i.e. statistical process control and design for manufacturability. These processes try to avoid defects or make it easier to detect defects. In software systems, this move to upstream processes for quality control is still in its early stages. As with more traditional manufacturing systems, maturity of the software design and development process will dramatically reduce the cost of attaining conformance to specifications. Even so, it is difficult to imagine a "bug-free" complex software system. Downstream processes will continue to play an important part in the efforts to achieve defect-free software. This paper presents results of a survey which used the defect detection tool Purify to examine off-the-shelf software products in order to show that software errors continue to escape testing and threaten field failures. Errors detected are compiled and presented. All data were collected on C and C++ programs running in a UNIX operating system environment.