Reliability Growth for Typed Defects

This paper presents a reliability growth model for defects that have been categorized into defect types associated with specific stages in the software development process. Modeling the reliability growth of defects for each type separately allows identification of problems in the development process which may otherwise be masked when defects of all types are modeled together. This paper Incorporates dependencies, from a failure detection point of view, between defects of two different types into a model for reliability growth. Uses typed defect data from three different software projects to validate the model. Finds that the defect detection rates are not equal for defects of different types within the project. Since each defect type can be associated with a software development stage, comparing the estimated defect detection rates and the dependency between types provides a basis for feedback on the process.