Task-Resource Capability Alignment: Discerning Staffing and Service Issues in Software Maintenance

The effective management of software maintenance processes involves decisions about workforce levels, skill and expertise mix of developers, assignment of defect resolution tasks, and monitoring key system performance measures. This research uses a queuing based simulation approach to study these managerial issues. Using the data archives of a large global software organization, an empirical study of the historical defect reports and management decisions is conducted. A task-resource capability alignment scheme is developed that captures the defect complexity and skill/experience capabilities of software maintainers. The results of the empirical-computational study show that the defect arrival/reporting process affects the resource utilization and the time a defect spends in the system. The results also highlight the role of dedicated and shared resources on the system performance and indicate that replacing an experienced and skilled developer requires a significant order of magnitude increase in the maintenance workforce.