Shyam R. Chidamber

A metrics suite for object oriented design

Given the central role that software development plays in the delivery and application of information technology, managers are increasingly focusing on process improvement in the software development area. This demand has spurred the provision of a number of new and/or improved approaches to software development, with perhaps the most prominent being object-orientation (OO). In addition, the focus on process improvement has increased the demand for software measures, or metrics with which to manage the process. The need for such metrics is particularly acute when an organization is adopting a new technology for which established practices have yet to be developed. This research addresses these needs through the development and implementation of a new suite of metrics for OO design. Metrics developed in previous research, while contributing to the fields understanding of software development processes, have generally been subject to serious criticisms, including the lack of a theoretical base. Following Wand and Weber (1989), the theoretical base chosen for the metrics was the ontology of Bunge (1977). Six design metrics are developed, and then analytically evaluated against Weyukers (1988) proposed set of measurement principles. An automated data collection tool was then developed and implemented to collect an empirical sample of these metrics at two field sites in order to demonstrate their feasibility and suggest ways in which managers may use these metrics for process improvement. >

Managerial use of metrics for object-oriented software: an exploratory analysis

With the increasing use of object-oriented methods in new software development, there is a growing need to both document and improve current practice in object-oriented design and development. In response to this need, a number of researchers have developed various metrics for object-oriented systems as proposed aids to the management of these systems. In this research, an analysis of a set of metrics proposed by Chidamber and Kemerer (1994) is performed in order to assess their usefulness for practising managers. First, an informal introduction to the metrics is provided by way of an extended example of their managerial use. Second, exploratory analyses of empirical data relating the metrics to productivity, rework effort and design effort on three commercial object-oriented systems are provided. The empirical results suggest that the metrics provide significant explanatory power for variations in these economic variables, over and above that provided by traditional measures, such as size in lines of code, and after controlling for the effects of individual developers.

Comments on "A metrics suite for object oriented design

A suite of object oriented software metrics has recently been proposed by S.R. Chidamber and C.F. Kemerer (see ibid., vol. 20, p. 476-94, 1994). While the authors have taken care to ensure their metrics have a sound measurement theoretical basis, we argue that is premature to begin applying such metrics while there remains uncertainty about the precise definitions of many of the quantities to be observed and their impact upon subsequent indirect metrics. In particular, we show some of the ambiguities associated with the seemingly simple concept of the number of methods per class. The usefulness of the proposed metrics, and others, would be greatly enhanced if clearer guidance concerning their application to specific languages were to be provided. Such empirical considerations are as important as the theoretical issues raised by the authors. >

Object-oriented programming: the promise and the reality

Abstract This article summarizes a workshop organized and conducted by the authors on April 1 and 2, 1993, under the auspices of Portland State University and the Oregon Center for Advanced Technology Education. This workshop provided a uniquely comprehensive and realistic look at the state of the art and practice of object-oriented programming. Issues discussed at the workshop and summarized here include the naturalness of object-oriented technology, reuse potential, programming support and evaluation tools, and the cost of converting to an object-oriented design technology. The findings should be of interest to researchers, organizations, and individuals who are exploring and/or using the object-oriented approach to software development. The article concludes by offering some recommendations for the use of objectoriented technology.