ODC - Orthogonal Defect Classification

The birth of ODC

Orthogonal Defect Classification (ODC), is a technique that bridges the gap between statistical defect models and causal analysis. It brings a scientific approach to measurements in a difficult area that otherwise can easily become adhoc. It also provides a firm footing from which classes of models and analytical techniques can be systematically derived. The goal is to provide an in-process measurement paradigm for extracting key information from defects and enable the metering of cause-effect relationships. Specifically, the choice of a set of orthogonal classes, mapped over the space of development or verification, can help developers by providing feedback on the progress of their software development efforts. These data and their properties provide a framework for analysis methods that exploit traditional engineering methods of process control and feedback.

A key study established a relationship between the statistical methods of software reliability prediction and the underlying semantic content in the defects used for the prediction [CKC91]. The study demonstrated that the characteristics of the defects, identified by the type of change necessary to fix defects had a strong influence in the maturity of a software product being developed. This opened the doors to the possibility of measuring product maturity via extracting the semantic content from defects and measuring their change as the process evolves. ODC systematizes such measurements based on semantics and enforces the basic rules to turn that into a measurement.

Once the method to create a measurement system via classification is established, one can start developing measurements of different attributes in a process. For instance, "cause" and "effect" attributes can be categorized separately and the measurements then used to develop cause/effect models or relationships. Similarly, several attributes can be separately categorized yielding a large multi-dimensional space which can be used to increase understanding and help develop the physics of the process. This process is akin to a scientist who measures, weighs, stretches and stresses a physical object to be able to understand it's characteristics. Once the physics of that object is understood the engineers know how to model and control that object. The basics of how to gain a fundamental understanding of a software product and process, were never elegantly established. ODC provides the first steps to do so.