A model for addressing software volatility in new system development

Software maintenance costs are well-documented as the largest component of software life cycle cost. While significant research has been conducted on the characterization of maintainability, program understanding, and softwar e organization for maintainability, there is little work published on the a priori identification and encapsulation of a software system's volatile po ints. In order to validate the fundamental behavior of enhancive software v olatility, a volatility-oriented maintenance life cycle cost model is prese nted to describe the relationship between frequency, cost-to-change, encaps ulation strategies, and the resulting life cycle cost. The behavior of this model is then correlated against historical change data from systems of a single domain. The paper also outlines a methodology for identifying the mo st probable points in software to experience the highest frequency of chang e, and using this postulated information as guidance in developing tools, o rganization, and techniques to make these points easy to change. (C) 1999 E lsevier Science Inc. All rights reserved.