Empirical studies of quality models in object-oriented systems

Measuring structural design properties of a software system, such as coupling, cohesion, or complexity, is a promising approach toward early quality assessments. To use such measurement effectively, quality models that quantitatively describe how these internal structural properties relate to relevant external system qualities such as reliability or maintainability are needed. This chapter's objective is to summarize, in a structured and detailed fashion, the empirical results reported so far with modeling external system quality based on structural design properties in object-oriented systems. We perform a critical review of existing work in order to identify lessons learned regarding the way these studies are performed and reported. Constructive guidelines for facilitating the work of future studies are also provided, thus facilitating the development of an empirical body of knowledge.