An examination of the effects of requirements changes on software maintenance releases

Requirements are the foundation of the software release process. They provide the basis for estimating costs and schedules, as well as developing design and testing specifications. When requirements have been agreed on by both clients and maintenance management, then adding to, deleting from, or modifying those existing requirements during the execution of the software maintenance process impacts the maintenance cost, schedule, and quality of the resulting product. The basic problem is not the changing in itself, but rather the inadequate approaches for dealing with changes in a way that minimizes and communicates the impact to all stakeholders. Using data collected from one organization on 44 software releases spanning seven products, this paper presents two quantitative techniques for dealing with requirements change in a maintenance environment. First, exploratory data analysis helps one to understand the sources, frequency, and types of changes being made. Second, a regression model helps managers communicate the cost and schedule effects of changing requirements to clients and other release stakeholders. These two techniques can help an organization provide a focus for management action during the software maintenance process. Copyright © 1999 John Wiley & Sons, Ltd.