Modularization Metrics: Assessing Package Organization in Legacy Large Object-Oriented Software

Abstract

There exist many large object-oriented software systems consisting of several thousands of classes that are organized into several hundreds of packages. In such software systems, classes cannot be considered as units for software modularization. In such context, packages are not simply classes containers, but they also play the role of modules: a package should focus to provide well identified services to the rest of the software system. Therefore, understanding and assessing package organization is primordial for software maintenance tasks. Although there exist a lot of works proposing metrics for the quality of a single class and/or the quality of inter-class relationships, there exist few works dealing with some aspects for the quality of package organization and relationship. We believe that additional investigations are required for assessing package modularity aspects. The goal of this paper is to provide a complementary set of metrics that assess some modularity principles for packages in large legacy object-oriented software: Information-Hiding, Changeability and Reusability principles. Our metrics are defined with respect to object-oriented inter-package and intra-package dependencies. The dependencies that are caused by different types of inter-class dependencies, such as inheritance and method call. We validate our metrics theoretically through a careful study of the mathematical properties of each metric.

Assessing the Bug-Prediction with Re-Usability Based Package Organization for Object Oriented Software Systems

“…Despite the importance of package-level design paradigms and its effect on software quality, there has not been much effort to evaluate this subject quantitatively. Nevertheless, the conceptual foundation of package modularization provided by Sarkar et al and Abdeen et al is healthy motivation of research in this area [6], [7]. And more recently, empirical analysis of package-modularization and its implications over software fault-proneness prediction by Zhao et al is indeed in line with our research direction [8].…”

“…Two dimensional reach-ability analysis has its main focus to retrieve the dependency information which impact the package design in terms of re-useability. Similarly, Our proposed index bear an implicit validation as it's computation and concept correspond to cohesion metrics discussed in the literature [7], [13], [19].…”

“…Result of this study was useful enough to understand behavior of class cohesion from the point of view of distance between the elements and depth of inheritance in software system. In particular, new principles of Information Hiding, assuming role of module as a service provider and implications of communication among different components have been acknowledged as contributing factors for measuring package based modular quality [7]. These efforts are aimed at redefining the modularization of software component with confined internal functioning and well-defined tasks.…”

Software Architecture Quality Measurement Stability and Understandability

“…Abdeen et al [27] introduced a complementary set of coupling and cohesion metrics that assess packages organization in large legacy object-oriented software. These metrics are aiming to measure the modularization for an object-oriented system.…”

Towards an Analytical Approach to Measure Modularity in Software Architecture Design

“…There has been much research conducted on measuring modularity considering coupling and cohesion which some of them have been offered in [5]- [8]. Most of them suggest several metrics to assess modularity.…”