A GOAL–QUESTION–METRIC (GQM)-BASED FRAMEWORK FOR MEASURING THE EXISTENCE OF LEGACY SOFTWARE SYSTEMS IN ORGANIZATIONAL ENVIRONMENTS
Abstract
Understanding the existence of legacy software systems is important for identifying how widely these systems are present within an organization and how strongly a selected legacy software system remains operationally present within its domain. Although many organizations recognize that legacy software systems exist, their presence is often described in general terms rather than measured through a structured and interpretable approach. This paper presents a Goal–Question–Metric (GQM)-based framework for measuring the existence of legacy software systems within organizational technical environments. The framework was developed through repeated GQM sessions, workshops, and discussions with technical leaders and specialists, with emphasis on objective and quantifiable indicators. It examines legacy software system existence through two complementary levels: the general existence of legacy software systems at the organizational level and the individual existence of a specific legacy software system within its operational domain. The general existence measure captures the proportion of legacy software systems within the overall software environment, while the individual existence measure captures active users, beneficiaries, and executed transactions related to a selected legacy software system. By translating existence assessment into defined goals, focused questions, measurable indicators, and numerical formulations, the proposed framework supports clearer evaluation of whether legacy software systems have limited, moderate, or strong presence. The proposed formulations are validated using real organizational data from public, private, semi-government, and international contexts. The validation results show that the existence measures can distinguish acceptable, pre-risk, and risk conditions and support more informed decisions regarding monitoring, modernization, reengineering, or replacement.
