Abstract
We present a methodology that aims at improving the effectiveness of requirements management in software development and maintenance. In particular, we address quantitative assessment of the impact of requirements changes, and quantitative estimation of costs of the development activities that must be carried out to accomplish those changes. Our approach is based on enhanced traceability and process measurement. Traceability relations are derived from an integrated view of the process and product models adopted within the software development organization. Hence, traceability spans over all the software life cycle and its products. Moreover, through proper measurement, the elements in the process and product models are quantitatively characterized, thus achieving a sound basis for different kinds of sophisticated analysis concerning the impact of requirements changes, their cost over the development process, and the sensitivity of the product to changes.