Prediction and Management of Program Quality

Techniques such as design reviews, code inspections, and system testing are commonly being used to remove defects from programs as early as possible in the development process. The objective of this paper is to demonstrate that predictors can be devised which tell us how well defects are being removed during the defect removal process. The approach is to develop a straightforward model of the defect removal process, and then use that model to develop formulas that show how measurable parameters—such as the ratio of major problems (MPs) removed by reviews and inspections to the number of problems (PTMs) removed by testing and the length (L) of an average problem fix—can be used to estimate: - Effectiveness of the overall defect removal process - Number of defects that remain at the time the product is first shipped to customers. On the bases of statistics for current products, numerical values for effectiveness measures can then be calculated.