Metrics for maintainability of class inheritance hierarchies

Abstract

Since the proposal for the six object-oriented metrics by Chidamber and Kemerer (1994), several studies have been conducted to validate their metrics and have discovered some deficiencies. Consequently, many new metrics for object-oriented systems have been proposed. Among the various measurements of objectoriented characteristics, we focus on the metrics of class inheritance hierarchies in design and maintenance. As such, we propose two simple and heuristic metrics for the class inheritance hierarchy for the maintenance of object-oriented software.In this paper we investigate the work of Chidamber and Kemerer (1994) and Li (1998), and extend their work to apply specifically to the maintenance of a class inheritance hierarchy. In doing so, we suggest new metrics for understandability and modifiability of a class inheritance hierarchy. The main contribution here includes the various comparisons that we have made. We discuss the advantages over Chidamber and Kemerer's (1994) metrics and Henderson-Sellers's (1996) metrics in the context of maintaining class inheritance hierarchies. Figure 6(a): (1 + 1 + 2 + 2 + 4)/5 = 2 AM of Figure 6(a): 2 + (2/2 + 2/2 + 1/2)/5 = 2.5 AU of Figure 6(b): (1 + 2 + 2 + 2)/4 = 1.75 AM of Figure 6(b): 1.75 + (3/2)/4 = 2.13 The understandability and modifiability of Figure 6(b) is better than Figure 6(a) in our metrics. AU of

Inheritance Metrics for Object-Oriented Design

“…Sheldon et al defines understandability, the ease of understanding a program structure or a class inheritance structure [40].…”

“…Sheldon et al [40] and Henderson Seller's [41] for comparison with proposed inheritance metric suites. In doing so, an attempt has been made to define empirical relationship between the proposed inheritance metric suites with the existing considered inheritance metrics and the focus was on which how the inheritance metric suites were correlated with the existing one.…”

“…Section 2 presents the brief overview of the inheritance metrics of F.T. Sheldon et al [40] and Henderson Seller's [41]. Section 3 presents the proposed inheritance metric suites and examples for illustration.…”

An empirical study of a reverse engineering method for the aggregation relationship based on operation propagation

“…Discovering relationships and interactions of these objects is not easy (Richner and Ducasse 1999). There is evidence which suggests that programmers have difficulty in maintaining object-oriented software because of inheritance depth and conceptual entropy of class hierarchies (Daly et al 1996;Sheldon et al 2002).…”

Assessing Software Maintainability Based on Class Diagram Design: A Preliminary Case Study

“…Therefore, class diagram offers a means to assessing the maintainability of OO systems at design stage. A few studies [3]- [13] have been conducted, and most of them are survey-based controlled experiments, which use participants" subjective opinions and some maintainability indices (e.g., the time for understanding a class diagram) to assess the  Manuscript received September 13, 2014; revised November 14, 2014. Yao Lu and Xinjun Mao are with National University of Defense Technology (NUDT), Changsha, China (e-mail: 839377654@qq.com).…”