Software cost estimation: Present and future

The state-of-the-art in software cost estimation is reviewed. The estimated cost of a software system varies widely with the model used. Some variation in cost estimation is attributable to the anomolies in the cost data base used in developing the model. The other variations, it is claimed are due to the presence or absence of certain ‘qualities’ in the final product. These qualities are measures of ‘goodness’ in design, development, and test-integration phases of software. To consider quality as a driver of software cost, we have suggested an association between cost and quality and have proposed a way to use quality metrics to estimate software cost.     

A fuzzy logic based approach for phase-wise software defects prediction using software metrics

ContextThe software defect prediction during software development has recently attracted the attention of many researchers. The software defect density indicator prediction in each phase of software development life cycle (SDLC) is desirable for developing a reliable software product. Software defect prediction at the end of testing phase may not be more beneficial because the changes need to be performed in the previous phases of SDLC may require huge amount of money and effort to be spent in order to achieve target software quality. Therefore, phase-wise software defect density indicator prediction model is of great importance.ObjectiveIn this paper, a fuzzy logic based phase-wise software defect prediction model is proposed using the top most reliability relevant metrics of the each phase of the SDLC.MethodIn the proposed model, defect density indicator in requirement analysis, design, coding and testing phase is predicted using nine software metrics of these four phases. The defect density indicator metric predicted at the end of the each phase is also taken as an input to the next phase. Software metrics are assessed in linguistic terms and fuzzy inference system has been employed to develop the model.ResultsThe predictive accuracy of the proposed model is validated using twenty real software project data. Validation results are satisfactory. Measures based on the mean magnitude of relative error and balanced mean magnitude of relative error decrease significantly as the software project size increases.ConclusionIn this paper, a fuzzy logic based model is proposed for predicting software defect density indicator at each phase of the SDLC. The predicted defects of twenty different software projects are found very near to the actual defects detected during testing. The predicted defect density indicators are very helpful to analyze the defect severity in different artifacts of SDLC of a software project.     

软件复用度量综述

软件复用度量是软件复用技术中不可分割的一部分,在软件复用开发中占据重要地位。软件复用开发与传统的软件开发方式不同,从而影响到软件度量,因此需要新的软件复用度量方法,软件复用度量的研究已经引起学术界的广泛重视。本文是一篇软件复用度量综述,阐述了软件复用对度量的影响以及有关软件复用的度量。     

Approach for estimating similarity between procedures in differently compiled binaries

ContextDetection of an unauthorized use of a software library is a clone detection problem that in case of commercial products has additional complexity due to the fact that only binary code is available.ObjectiveThe goal of this paper is to propose an approach for estimating the level of similarity between the procedures originating from different binary codes. The assumption is that the clones in the binary codes come from the use of a common software library that may be compiled with different toolsets.MethodThe approach uses a set of software metrics adapted from the high level languages and it also extends the set with new metrics that take into account syntactical changes that are introduced by the usage of different toolsets and optimizations. Moreover, the approach compares metric values and introduces transformers and formulas that can use training data for production of measure of similarities between the two procedures in binary codes. The approach has been evaluated on programs from STAMP benchmark and BusyBox tool, compiled with different toolsets in different modes.ResultsThe experiments with programs from STAMP benchmark show that detecting the same procedures recall can be up to 1.44 times higher using new metrics. Knowledge about the used compiling toolset can bring up to 2.28 times improvement in recall. The experiment with BusyBox tool shows 43% recall for 43% precision.ConclusionThe most useful newly proposed metrics are those that consider the frequency of arithmetic instructions, the number and frequency of occurrences for instructions, and the number of occurrences for target addresses in calls. The best way to combine the results of comparing metrics is to use a geometric mean or when previous knowledge is available, to use an arithmetic mean with appropriate transformer.     

基于软件完整性级别的软件可靠性度量选取框架

选取合适的软件可靠性度量,对于软件质量保证及项目管理有着重要意义。现有的软件可靠性度量选取方法没有考虑软件完整性级别这个重要的设计属性。完整性级别表示软件特性的取值范围,该范围对将系统风险保持在可容忍的限度内是必需的,其对软件可靠性水平有显著影响。提出了一种基于完整性级别的可靠性度量选取框架:首先给出基于完整性级别的度量选取体系;然后在选取体系的基础上,给出相应的度量选取方法;最后,将提出的度量选取框架应用于ISO/IEC 9126质量模型中的外部软件可靠性度量,根据度量的特点将每种度量不同程度(基本、条件及参考)地推荐给不同的完整性级别。实例表明,基于完整性级别的度量选取技术是系统且有效的,所推荐的度量可以满足软件尤其是安全关键软件在不同完整性级别上的需求。     

Controlling and predicting the quality of space shuttle software using metrics

Software quality metrics have potential for helping to assure the quality of software on large projects such as the Space Shuttle flight software. It is feasible to validate metrics for controlling and predicting software quality during design by validating metrics against a quality factor. Quality factors, like reliability, are of more interest to customers than metrics, like complexity. However quality factors cannot be collected until late in a project. Therefore the need arises to validate metrics, which developers can collect early in a project, against a quality factor. We investigate the feasibility of validating metrics for controlling and predicting quality on the Space Shuttle. The key to the approach is the use of validated metrics for early identification and resolution of quality problems.     

The evaluation of software systems' structure using quantitative software metrics

The design and analysis of the structure of software systems has typically been based on purely qualitative grounds. In this paper we report on our positive experience with a set of quantitative measures of software structure. These metrics, based on the number of possible paths of information flow through a given component, were used to evaluate the design and implementation of a software system (the UNIX operating system kernel) which exhibits the interconnectivity of components typical of large-scale software systems. Several examples are presented which show the power of this technique in locating a variety of both design and implementation defects. Suggested repairs, which agree with the commonly accepted principles of structured design and programming, are presented. The effect of these alterations on the structure of the system and the quantitative measurements of that structure lead to a convincing validation of the utility of information flow metrics.     

基于度量工具的软件成本估算模型使用方法

输入的主观性以及输入过多是妨碍软件成本估算模型实际应用效果的重要影响因素。针对以上问题,提出了一种基于度量工具的软件成本估算模型使用方法。该方法通过引入统计理论中的工具变量,将度量工具所采集的度量元数据自动转换为软件成本估算模型的输入。这一方面可以避免模型校准和估算过程中输入的主观性与不一致性,提高了估算结果的准确性与可靠性;另一方面能减少估算人员的手工操作,提高工作效率,增加了软件成本估算模型的可用性。结合具体实例说明了所提出方法的可行性与有效性。     

软件可修改性在软件开发过程中的控制*

在传统的软件可修改性定义的基础上提出了基于软件开发过程的软件可修改性,确定了垂直软件可修改性和水平软件可修改性的关系和基本度量方法。建立了基于软件开发过程的软件可修改性模型,得到了软件开发过程各阶段中软件可修改性的度量方法,从而为在软件开发过程中控制软件的可修改性提供了基础。     

一种软件过程质量的度量方法

提出了一种软件过程质量度量的流程,建立了一个以生命周期为基础的软件过程质量度量模型,将软件过程质量要素分解成了共性软件过程质量要素和个性软件过程质量要素两大类,分析了相应的质量要素、质量子要素和度量元,给出了相应的度量方法。最后利用该度量方法对某公司5个软件项目需求阶段的过程质量及软件开发后期需求稳定性因子进行了度量,经数据分析发现软件开发后期的需求稳定性因子与需求阶段的过程质量是正相关的,从而表明了提出的度量方法和度量模型是有效的。     

一种扩展UML/UP的需求分析方法

UML是面向对象分析和设计的工业标准;UP(Unified Process,统一过程)是使用UML作为建模语言的软件工程过程.UML和UP结合在一起成为一种很强大的软件工程方法学.UML/UP作为方法学,在需求方面存在两大不足:需求表达能力不强;需求表达与后续的系统分析和设计有较大的鸿沟.分析了需求工程中用例和场景分析以及用例图示的高层设计方法.在此基础上,提出了在需求方面增强了UML/UP方法.     

软件度量学综述

该文将介绍软件度量学的发展历史、软件质量度量体系和软件度量方法。着重分析面向对象软件开发技术的发展对软件度量方法的影响。最后给出了下一步研究方向。     

Java语言的度量及工具实现

简述了面向对象软件度量的最新进展,并设计和实现了基于目前流行的Ｃ＆Ｋ度量方法的Ｊａｖａ语言度量工具。     

青鸟构件库的构件度量

对软件产业发展所需要的软件生产率和软件质量的重视引起了对软件复用技术的研究,同时,有关复用度量的研究和应用也引起了广泛的重视.青鸟构件库系统可以对可复用构件进行描述、管理、存储和检索,用以满足基于“构件-构架”复用的软件开发过程的需要.该文介绍了青鸟构件库中的构件度量模型,并阐述了利用青鸟程序分析系统中的面向对象度量工具和青鸟构件库后期度量系统(包括反馈信息的收集、处理和分析工具)来实现模型的方法.     

用动态度量方法加强软件开发过程管理

软件开发过程管理的研究远远落后于开发技术、工具等方面的研究。通过描述软件开发过程的动态度量的方法,从生产的概念出发,给出软件开发动态度量的流程、方法,论述了管理、度量和数据元素选择的原则,从动态度量方法加强软件开发过程的角度作了探索性研究。     

软件度量的操作模型

软件企业在实施软件度量的过程中面临最主要的障碍是如何将软件度量转换成可实施的、体现组织过程特征的度量实施过程模型.为解决这一问题,本文基于"软件度量过程也是软件"的思想给出组织级实施软件度量的操作模型OMMP,在此基础上,对基于度量的过程管理框架进行讨论,将度量集成在过程管理框架中.     

Complexity measurement of a graphical programming language

For many years the software engineering community has been attacking the software reliability problem on two fronts. First via design methodologies, languages and tools as a pre-check on complexity and secondly by measuring the complexity of produced software as a post-check. This research attempts to unify the approach to creating reliable software by providing the ability to measure the complexity of a design prior to its implementation. We have successfully defined and applied software metrics to graphical designs in an effort to predict software complexity early in the software life cycle. Metric values from the graphical design are input to predictor equations, provided in this paper, to give metric values for the resultant source code.     

核级软件的验证与确认技术研究

核级软件的验证与确认是核电数字化仪控系统研发的关键,用以确保核级软件设计过程的透明性,验证软件需求规格的完整性,确认核级软件功能与设计需求规格的一致性、正确性。核级软件的验证与确认概要地分成软件设计过程的管理技术及软件的测试技术,本文遵循IEC60880以及IAEA的核级软件的验证与确认导则,侧重研究核级软件验证与确认中的需求验证与软件测试技术,通过开发一种自动化V＆V工具,实现核级控制系统应用软件的一套自动化V＆V流程。     

Techniques of Successful Application of Factor Analysis in Software Measurement

Metrics in a software sense can be roughly divided into two groups, internal metrics and external metrics. Internal metrics can be measured directly, while external metrics are predicted using internal metrics. Factor analysis is a statistical technique which can be applied to analyze the structure of internal metrics and form a prediction model for external metrics A prediction model generated by using factor analysis needs further validation since factor analysis has a non-unique solution for the factor-loading matrix. The computational methodology to establish a model is presented as well as the validation process. This is illustrated by an empirical study of design metrics and a prediction model for design quality.     

基于堆叠泛化的设计模式检测方法

设计模式检测是理解和维护软件系统的一项重要工作.以高效识别设计模式变体和提高设计模式识别准确率为目的，将面向对象度量与模式微结构相结合，提出一种基于堆叠泛化的设计模式检测方法.该方法应用典型的机器学习算法，分别训练度量分类器和微结构分类器，并基于两者的预测值和相关对象模型特征进一步训练，从而形成堆叠分类器.为了评估该方法，基于该方法开发了一个原型工具OOSdpd.该工具从Java字节码级别的系统实现中抽取设计模式实例，并在JUnit等几个经典的开源项目上进行实验.通过与现有的两种工具进行对比分析，实验验证了该方法在提高设计模式识别准确率及召回率方面的有效性.