Avoiding metric monsters: A design metrics approach

Metric monsters are stumbling blocks that prevent software metrics-guided methodologies from attaining product and process improvement. Metric monsters can occur during the identification, collection or application of software metrics. In our research, we have developed and tested our design metrics over a five-year period and have found them to be excellent predictors of error-prone modules. Based on this research, we will identify some of the monsters that occur in the quantitative analyses of software and its development processes, and present our approach in formulating a design metrics model that avoids these monsters. This model consists of software tools, guidelines and actions for the application of software design metrics.     

Cultivation and engineering of a software metrics program

Abstract. This paper reports from a case study of an organization that implements a software metrics program to measure the effects of its improvement efforts. The program measures key indicators of all completed projects and summarizes progress information in a quarterly management report. The implementation turns out to be long and complex, as the organization is confronted with dilemmas based on contradictory demands and value conflicts. The process is interpreted as a combination of a rational engineering process in which a metrics program is constructed and put into use, and an evolutionary cultivation process in which basic values of the software organization are confronted and transformed. The analysis exemplifies the difficulties and challenges that software organizations face when bringing known principles for software metrics programs into practical use. The article discusses the insights gained from the case in six lessons that may be used by Software Process Improvement managers in implementing a successful metrics program.     

面向对象设计复杂性度量计算与分析

软件维护在软件开发过程中占有相当重要的位置,但是其成本往往是很难控制的.在对一种能够对软件维护性能进行预测的面向对象复杂性度量进行分析的基础上,结合实际情况分析了该算法集3个度量的缺点及联系.对于3个度量不够深入的地方补充了一些新观点.     

Identification of defect-prone classes in telecommunication software systems using design metrics

The goal of this paper is to investigate the relation between object-oriented design choices and defects in software systems, with focus on a real-time telecommunication domain. The design choices are measured using the widely accepted metrics suite proposed by Chidamber and Kemerer for object oriented languages [S.R. Chidamber, C.F. Kemerer, A metrics suite for object oriented design, IEEE Transactions on Software Engineering 20 (6) (1994) 476-493].This paper reports the results of an extensive case study, which strongly reinforces earlier, mainly anecdotal, evidence that design aspects related to communication between classes can be used as indicators of the most defect-prone classes.Statistical models applicable for the non-normally distributed count data are used, such as Poisson regression, negative binomial regression, and zero-inflated negative binomial regression. The performances of the models are assessed using correlations, dispersion coefficients and Alberg diagrams.The zero-inflated negative binomial regression model based on response for a class shows the best overall ability to describe the variability of the number of defects in classes.     

Models,metrics, and management of IS development

Two types of models can assist the information system manager in gaining greater insight into the system development process. They are: isomorphic models that represent cause-effect relationships between certain conditions (e.g., structured techniques) and certain observable states (e.g., productivity change); and paramorphic models that describe an outcome but do not describe the processes or variables that influence the outcome (e.g., estimation of project time or cost). The two models are shown to be interrelated since the relationships of the first model are determinants of the parameters of the second model.IS managers can make significant contributions by developing isomorphic models tailored to their own organizations. However, metrics that measure relevant characteristics of programs and systems are required before substantial progress can be made. Although some initial attempts have been made to develop metris for program quality, program complexity, and programmer skill, much more work remains to be done. In addition, other metries must be developed that will require the involvement of personnel, not only in the computer sciences, but also in information systems, the behavioral sciences, and IS management.     

软件构件质量度量

基于软件质量标准ISO／IEC9126：2001《软件工程产品质量》,探讨了软件构件的质量度量问题,首次提出了完整的软件构件质量模型：外部和内部质量模型以及使用质量模型,为度量软件构件质量提供了新的方法。最后以外部易组装性度量为例,给出了软件构件质量度量的量化方法。     

专家系统规则库覆盖度量的研究及实践

针对专家系统规则库的软件测试和评价是保证专家系统质量与可靠性的重要环节。基于数据流的结构化测试技术,提出了一种规则库执行流图RBEF,用于描述规则库中不同规则之间相互连结、制约关系,进而给出了一组规则库覆盖度量准则和测试用例的设计方法,最后讨论了一个已实现并付诸于应用的基于RBEF的软件测试工具ESRTS。     

An exploratory study on cooccurrence of design patterns and bad smells using software metrics

A design pattern is a general reusable solution to commonly recurring problems in software projects. Bad smells are symptoms existing in the source code that possibly indicate the presence of a structural problem that requires code refactoring. Although design pattern and bad smells be different concepts, literature has shown that they may be related and cooccur during the evolution of a software system. This paper presents an empirical study that investigates cooccurrences of design patterns and bad smells as well as identifies the main factors that contribute to the emergence of the relationship between them. We carried out a case study with five Java systems to: (1) investigate if the use of design pattern reduces bad smell occurrence, (2) identify cooccurrences of design patterns and bad smells, and (3) identify situations that contribute for the cooccurrence emergence. As the main result, we found that the application of design pattern not necessarily avoid bad smell occurrences. The results also show that some design patterns such as composite, factory method, and singleton, are intrinsically modular and might be useful in creating high-quality systems. However, other design patterns such as adapter-command, proxy, and state-strategy, have presented high cooccurrence frequency with bad smells; therefore, they require attention in their implementation. Finally, via manual inspection in the components with cooccurrence, we found that the identified cooccurrences appeared due to poor planning and inadequate application of design patterns.     

Aspect‐oriented component assembly—a case study in parallel software design

In this paper we deal with building parallel programs based on sequential application code and generic components providing specific functionality for parallelization, like load balancing or fault tolerance. We describe an architectural approach employing aspect‐oriented programming to assemble arbitrary object‐oriented components. Several non‐trivial crosscutting concerns arising from parallelization are addressed in the light of different applications, which are representative of the most common types of parallelism. In particular, we demonstrate how aspect‐oriented techniques allow us to leave all existing code untouched. We evaluate and compare our approach with its counterparts in conventional object‐oriented programming. Copyright © 2008 John Wiley & Sons, Ltd.     

Statistical methods for the analysis of software metrics data

The authors present case study applications of statistical methods for the analysis of software metrics data which recognize the discrete nature of such data. A procedure is also described which allows a component of complexity independent of size to be extracted from the usual Halstead's metrics and McCabe's cyclomatic number. The methods described are different from the usual regression and non-parametric methods previously applied to software metrics. With the software quality practitioner in mind, the paper explores how these new methods are helpful in understanding the relationships between software metrics.     

基于ADA语言的星载软件在轨编程技术研究

随着ADA编程语言被引入到星载软件的开发中,相比较汇编编程语言,用ADA编程语言可以大大提高软件的可复用性,缩短开发周期并进而降低开发成本。但同时,如何利用ADA编程语言更好地实现对卫星的计算机软件的在轨编程功能这一课题也被提到了桌面上来了。该文对如何利用ADA编程语言实现对卫星的计算机软件的在轨编程功能进行了研究,并提出了一种设计方案和实现技术,使其能够充分利用ADA编程语言的可复用性高的特点并同时能够满足高安全性和高实时性的要求。     

A set of complexity metrics for guiding the software test process

Software verification and validation is a domain which is covered by many dynamic test, static analysis, and formal verification techniques. This presents a problem to practitioners with respect to selecting those suitable techniques which can be used successfully. The basic idea of the methodology presented here is to select test techniques which fit the software under test. A dynamic test technique requires that certain program elements are covered, will be sensitive to errors associated with these elements, because executing an error location is a precondition for revealing the error. Furthermore, it is likely that the probability of errors increases with complexity. Complexity can be characterized in terms of several properties which can be used to suggest various testing strategies. The complexity of the various software properties can be measured using appropriate complexity metrics. Properties with unusual high complexity measures should be tested very throughly. The approach described in this paper permits the selection of test techniques based on the values of the metrics with respect to a particular software product.     

Programming Languages in Economics

Young economists sometimes ask which computer programming languages they should learn. This paper answers that question by suggesting that they begin with a high level language like GAUSS, GAMS, Mathematica, Maple or MATLAB depending on their field of specialization in economics. Then they should work down to one of the low level languages such as Fortran, Basic, C, C++ or Java depending on the planned areas of application. Finally, they should proceed to the languages which are used to develop graphical interfaces and internet applications, viz. Visual Basic, C, C++ or Java.     

An Introduction to SequenceL: A Language to Experiment with Constructs for Processing Nonscalars

SequenceL is a language intended for experimentation with declarative constructs for nonscalar processing. In SequenceL, a problem solver provides little in the way of iterative/recursive details in a problem solution. Instead, the problem solver describes the solution directly by specifying, via a metastructure, the data structures which will hold results useful for solving the problem. SequenceL is a small language (i.e. there is a small number of language constructs), and it is not domain dependent. This paper is meant to introduce the reader to SequenceL.     

Illustrating Client and Implementation Readability Tradeoffs in Ada and C++

The relative merits of Ada and C++ have fostered numerous discussions among software developers. With the release of Ada 95 and its object-oriented features, we expect these discussions to intensify, particularly given the increasing number of features for which there are implementations in both languages. In this paper, we compare Ada and C++ based on the readability of class and client implementations. We examine this issue using a case study. Our case study illustrates a partial tradeoff that exists between the readability of a class and the readability of its clients. This tradeoff depends on the degree to which overloading is used; extensive use of overloading adds to class complexity, although it increases client readability.     

一种用于监控系统的监控指标趋势分析方法

提出一种用于监控系统的监控指标的趋势分析方法,包括两种趋势分析,分别为预测分析和周期性分析,前者通过线性回归算法和指数回归算法预测指标的未来值;后者通过三角函数回归算法计算指标的周期性参数。根据趋势分析结果和事先设定的报警阈值确定是否预先报警,绘制该指标变化的周期性曲线。该方法能够实现网络监控系统在监控指标发生违例前预先报警,自动生成指标变化周期性曲线,为监控系统增加了趋势分析功能。     

Applying and evaluating concern-sensitive design heuristics

Manifestation of crosscutting concerns in software systems is often an indicative of design modularity flaws and further design instabilities as those systems evolve. Without proper design evaluation mechanisms, the identification of harmful crosscutting concerns can become counter-productive and impractical. Nowadays, metrics and heuristics are the basic mechanisms to support their identification and classification either in object-oriented or aspect-oriented programs. However, conventional mechanisms have a number of limitations to support an effective identification and classification of crosscutting concerns in a software system. In this paper, we claim that those limitations are mostly caused by the fact that existing metrics and heuristics are not sensitive to primitive concern properties, such as either their degree of tangling and scattering or their specific structural shapes. This means that modularity assessment is rooted only at conventional attributes of modules, such as module cohesion, coupling and size. This paper proposes a representative suite of concern-sensitive heuristic rules. The proposed heuristics are supported by a prototype tool. The paper also reports an exploratory study to evaluate the accuracy of the proposed heuristics by applying them to seven systems. The results of this exploratory analysis give evidences that the heuristics offer support for: (i) addressing the shortcomings of conventional metrics-based assessments, (ii) reducing the manifestation of false positives and false negatives in modularity assessment, (iii) detecting sources of design instability, and (iv) finding the presence of design modularity flaws in both object-oriented and aspect-oriented programs. Although our results are limited to a number of decisions we made in this study, they indicate a promising research direction. Further analyses are required to confirm or refute our preliminary findings and, so, this study should be seen as a stepping stone on understanding how concerns can be useful assessment abstractions. We conclude this paper by discussing the limitations of this exploratory study focusing on some situations which hinder the accuracy of concern-sensitive heuristics.     

在软件易变性上下文中类规模对面向对象度量的影响分析

软件易变性预测主要通过软件的内部特性,即软件度量值,来刻画、预测的,是软件工程中热点方向之一,在提高软件质量和控制软件成本方面起着非常重要的作用。虽然软件易变性预测在学术界取得了一系列的成绩,但在工业界尚未有成功应用的案例。本文从简单相关性分析与偏相关性分析和关联规则挖掘的角度出发甄别面向对象度量与软件易变性间相关性的真伪,明确了在软件易变性上下文中类规模对面向对象度量有潜在影响。     

Investigating ARIMA models of software system quality

In this paper, we investigate how to incorporate program complexity measures with a software quality model. We collect software complexity metrics and fault counts from each build during the testing phase of a large commercial software system. Though the data are limited in quantity, we are able to predict the number of faults in the next build. The technique we used is called times series analysis and forecasting. The methodology assumes that future predictions are based on the history of past observations. We will show that the combined complexity quality model is an improvement over the simpler quality only model. Finally, we explore how the testing process used in this development may be improved by using these predictions and suggest areas for future research.     

A parallel language and its programming system for heterogeneous networks

The paper presents a new parallel language, mpC, designed specially for programming high‐performance computations on heterogeneous networks of computers, as well as its supportive programming environment. The main idea underlying mpC is that an mpC application explicitly defines an abstract network and distributes data, computations and communications over the network. The mpC programming environment uses, at run time, this information as well as information on any real executing network in order to map the application to the real network in such a way that ensures the efficient execution of the application on this real network. Experience of using mpC for solving both regular and irregular real‐life problems on networks of heterogeneous computers is also presented. Copyright © 2000 John Wiley & Sons, Ltd.