Managing the maintenance of ported, outsourced, and legacy software via orthogonal defect classification

From the perspective of maintenance, software systems that include COTS software, legacy, ported or outsourced code pose a major challenge. The dynamics of enhancing or adapting a product to address evolving customer usage and the inadequate documentation of these changes over a period of time (and several generations) are just two of the factors which may have a debilitating effect on the maintenance effort. While many approaches and solutions have been offered to address the underlying problems, few offer methods which directly affect a team's ability to quickly identify and prioritize actions targeting the product which is already in front of them. The paper describes a method to analyze the information contained in the form of defect data and arrive at technical actions to address explicit product and process weaknesses which can be feasibly addressed in the current effort. The defects are classified using Orthogonal Defect Classification (ODC) and actual case studies are used to illustrate the key points.