Evaluating the reliability of the software of a switching system with a multi-variable model

In recent years reliability growth models have gained a dominant role in the evaluation of the reliability of software products. However, their application to the quality assurance process of the software of a highly complex system such as a telecommunications switching system often shows that it is then possible to get accurate results only when some months of operation have elapsed. It is then impossible to give an answer to the typical questions which arise during the quality assurance phase: ‘Is the software ready for release? How long will it take before it is ready?’. This paper describes a multi-variable (MV) model which was developed to overcome the above limitation by providing a better model of the quality assurance process. A case study is presented, and a comparison is made between the results obtained by applying existing reliability growth models and the MV-model to it. Besides attaining surprising accuracy in its predictions and in measuring the reliability of the product, the MV-model also tries to tackle a different kind of question: ‘How is it possible to improve the effectiveness of testing?’.     

基于状态验证覆盖的Bayes软件可靠性评估

传统的可靠性评估方法都是基于系统软件运行期间的失效,对于武器系统软件,由于其使用试验耗费巨资且周期很长,不可能对系统进行过多的使用试验,导致难以采集到高质量的失效数据。提出一种基于系统状态验证覆盖的Bayes软件可靠性评估方法,该方法以Bayes可靠性模型为评估准则,通过状态覆盖率来保证充分性,通过状态测试验证来保证可靠性,提倡可信性与可靠性并行增长。     

统计测试的软件可靠性保障能力研究

研究了统计测试对不同软件的测试能力,提出将测试有效性信息综合到软件可靠性评估模型中,以提高可靠性估计的针对性和精度.通过实验证明了该方法的合理性.该方法为高可靠性的软件质量保障要求提供了途径和可能.     

基于随机Petri网的软件可靠性分析方法

软件可靠性模型对于软件可靠性估测起着核心作用.目前提出的模型大多数都不能很好的适应复杂多变的应用环境的要求.针对构件化软件提出了一种基于随机Petri网的软件可靠性分析方法,它符合尽可能在软件开发的上游阶段对软件进行可靠性评估的思想.使用该方法建立起的模型可以很好的描述软件系统的动态变化过程,尽可能多的考虑了影响软件可靠性的因素,有利于降低软件可靠性描述与分析的复杂度,并可以得到软件系统处于各个状态的瞬时及稳态概率.     

软件测试中可靠性模型的设计与研究

软件测试是保证软件质量和提高软件可靠性的关键所在,而软件可靠性是衡量软件质量的重要指标之一,二者有着非常紧密的联系。软件可靠性模型既是软件可靠性进行定量分析的基础和保障,也是软件可靠性进行预测的核心和关键,对保证软件质量起到了非常重要的作用。文中结合软件测试与软件可靠性及其模型的相关理论,通过对Seeding模型的分析与改进,提出了一种适用于软件测试的可靠性模型。实验结果表明,使用文中提出的软件可靠性模型能较好地满足软件对可靠性评估的要求,较好地应用在软件测试中。     

Making Software Visible, Operational, and Maintainable in a Small Project Environment

Practical suggestions are presented for effectively managing software development in small-project environments (i.e., no more than several million dollars per year). The suggestions are based on an approach to product development using a product assurance group that is independent from the development group. Within this check-and-balance management/development/product assurance structure, a design review process is described that effects an orderly transition from customer needs statement to software code. The testing activity that follows this process is then explained. Finally, the activities of a change control body (called a configuration control board) and supporting functions geared to maintaining delivered software are described. The suggested software management practices result from the experience of a small (approximately 100 employees) software engineering company that develops and maintains computer systems supporting real-time interactive commercial, industrial, and military applications.     

基于UML的软件使用模型的研究与实现

UML作为事实上的工业标准,在软件开发中得到了日益广泛的应用。软件可靠性测试是高可靠软件质量保证的重要过程。研究基于UML的软件可靠性测试具有很强的现实意义。软件使用模型是进行软件可靠性测试的基础,可利用在软件开发早期阶段生成的UML模型,如用况图、顺序图、活动图,自动生成软件使用模型。     

基于构件的Web系统前馈神经网络可靠性模型

对基于构件结构复杂度较高的Web系统进行可靠性评估时,基于状态或基于路径的软件可靠性评估模型计算复杂度较高,鲁棒性不足。为此,提出了一种计算复杂度低、鲁棒性强的基于构件的前馈神经网络可靠性模型CBPRM。CBPRM将Web系统中各构件的可靠性作为前馈神经网络输入,并基于构件可靠性敏感度对神经元进行动态优化,Web系统可靠性评估由前馈神经网络输出实现。理论分析和实验结果表明,在基于构件结构复杂度较高的Web系统可靠性评估中,CBPRM的计算复杂度低于对比模型,并可确保可靠性评估精度。     

SREPT: software reliability estimation and prediction tool

Several tools have been developed for the estimation of software reliability. However, they are highly specialized in the approaches they implement and the particular phase of the software life-cycle in which they are applicable. There is an increasing need for a tool that can be used to track the quality of a software product during the software life-cycle, right from the architectural phase all the way up to the operational phase of the software. Also the conventional techniques for software reliability evaluation, which treat the software as a monolithic entity, are inadequate to assess the reliability of heterogeneous systems, which consist of a large number of globally distributed components. Architecture-based approaches are essential to assess the reliability and performance of such systems. This paper presents the high-level design of a software reliability estimation and prediction tool (SREPT), that offers a unified framework consisting of techniques (including the architecture-based approach) to assist in the evaluation of software reliability during all phases of the software life-cycle.     

基于UML的软件使用模型生成技术研究

软件可靠性测试是高可靠软件质量保证的重要过程，而软件使用模型则是进行软件可靠性测试的基础。UML(Unified Modeling Language)作为事实上的工业标准，在软件开发中得到了日益广泛的应用。研究基于UML的软件可靠性测试具有很强的现实意义。利用在软件开发早期阶段生成的UML模型，如用例图、顺序图、活动图，可以生成软件使用模型，进而可据此产生测试用例。     

基于序列的可靠性分析方法

随着软构件技术的快速发展，基于构件设计复杂软件系统的软件开发方法日趋成熟。如何利用系统架构和软构件的可靠性分析软件系统的可靠性成为一个亟待解决的问题。软件是静态的，而开发过程是动态的。为了在动态的开发过程中跟踪可靠性，本文提出了基于序列的场景模型，以便分析软件可靠性。与相关的其他方法不同的是，该方法更关注于动态开发过程中的可靠性分析。     

软件可靠性多模型综合的预测方法

针对软件可靠性工程领域中存在的不同可靠性模型预测相同软件结果不一致的问题，提出了一种用神经网络实现的软件可靠性多模型综合预测方法，能够有效地解决软件工程中的实际问题，通过实例分析验证了该方法的有效性。     

基于未确知理论的软件可靠性建模

将未确知理论应用于软件可靠性建模研究,采用其分析软件故障过程,用未确知数学描述软件失效特征计算软件可靠性参数,并在此基础上构建了一个基于未确知数学理论的软件可靠性模型.新模型改变了传统的建模思路,跳出了传统软件可靠性建模过程中关于失效强度变化的各种统计分布假设的束缚,具有较好的适用性,改善了模型应用中的不一致性问题.     

计算机软件工程标准在智能电网建设中的应用探讨

从紧贴市场法则需求、强化执行标准意识,掌握软件工程体系标准、正确合理引用软件标准,重视软件开发过程控制、提高软件产品开发质量,遵循计算机软件工程标准、提高软件产品可靠性等方面,阐述了正确理解和严格遵循计算机软件工程国家标准,对于指导软件产品开发、规范产品开发流程、保证产品开发质量,为建设坚强智能电网提供技术支撑;并从学习、研究、遵循和应用计算机软件工程国家标准,规范软件产品过程控制,提高软件产品质量等方面提出了思路与建议。     

基于构件软件的可靠性通用模型

工作流管理的最终目的是实现适当的人在适当的时间执行适当的活动.企业要获得竞争力,需要在工作流模型中考虑与业务过程相关的时间约束.一个考虑时间因素的工作流模型,需要在投入运行前进行时间规范与验证,以保证工作流执行的时间协调.通过为工作流网元素扩展时间属性,得到集成业务过程时间约束的工作流模型??时间约束工作流网(TCWF-nets).基于对业务活动的可调度性分析,提出了时序一致性验证方法,确保工作流执行中活动之间时间交互的安全性.在所附加的时间约束下,该可调度分析方法不仅能够检测某一给定工作流调度的时间可行性,还能对特定的实例给出一个最优调度,使工作流执行延迟最小.研究结果表明,该方法支持业务过程的时间建模与分析,对于丰富现有工作流系统的时间管理功能以及增强现存工作流软件对动态业务环境的适应性具有重要意义.     

一种面向开发过程的软件可靠性预测方法

在进行软件开发时,该如何回答这样的问题,＂当前开发的软件可靠性是什么？＂这个对于用户来说是非常重要的信息,却难以表述。以此为方向,研究了一种面向开发过程的软件可靠性预测方法,结合软件开发各个阶段的特点,通过合理地采用软件可靠性早期预测模型,实现对开发中软件可靠性的预测。实践应用表明,该方法紧密结合软件开发的实际,反映了软件可靠性与开发人员的水平、开发规范的标准之间的联系,有助于采取必要的措施提高其以后的可靠性,从而也验证了该方法的工程实用性。     

基于服务更新的网构软件可靠性模型研究(英文)

网构软件是在开放、动态和多变的Internet环境下软件系统基本形态的一种抽象。这种新的软件系统,它的构建依赖于开放环境中各异构、自治的软件服务实体之间的有效协同。其可靠性不单取决于拥有自主性的软件服务实体本身,还取决于外部环境的动态变化,主要表现为开放环境下服务实体元素的更新,所以传统的软件可靠性的度量模型已不能适应这种新的软件形态。能否在网构软件形态下建立一个好的可靠性度量模型成为其中一个较为核心的问题。文章以服务更新过程中失效数(failurecounts)为基础,将服务更新强度引入Musa-Okumoto(M-O)模型中,作为M-O模型在新的软件形态下的一个推广。最后讨论了网构软件退化的情形和退化条件,为开放环境下网构软件可靠性研究提供一种思路。     

基于基准比对思想的软件可靠性预测仿真建模研究

可靠性作为衡量软件质量的重要特性,其定量评估和预测已成为人们关注和研究的焦点。本文针对这个问题展开研究,提出一个可用于软件测试之前的早期可靠性预测仿真模型。此仿真模型通过考查影响软件可靠性的过程因素,采用基准比对思想,利用软件过程度量数据,根据相似度比较,预测软件的残留缺陷数。由于该仿真模型仅需要静态历史数据,故可在软件测试之前,用于估计软件的残留缺陷数,从而预测软件的可靠性,为后期软件过程的改进以及软件测试计划的修正提供依据。     

Optimal and adaptive testing for software reliability assessment

Optimal software testing is concerned with how to test software such that the underlying testing goal is achieved in an optimal manner. Our previous work shows that the optimal testing problem for software reliability growth can be treated as closed-loop or feedback control problem, where the software under test serves as a controlled object and the software testing strategy serves as the corresponding controller. More specifically, the software under test is modeled as controlled Markov chains (CMCs) and the control theory of Markov chains is used to synthesize the required optimal testing strategy. In this paper, we show that software reliability assessment can be treated as a feedback control problem and the CMC approach is also applicable to dealing with the optimal testing problem for software reliability assessment. In this problem, the code of the software under test is frozen and the software testing process is optimized in the sense that the variance of the software reliability estimator is minimized. An adaptive software testing strategy is proposed that uses the testing data collected on-line to estimate the required parameters and selects next test cases. Simulation results show that the proposed adaptive software testing strategy can really work in the sense that the resulting variance of the software reliability estimate is much smaller than that resulting from the random testing strategies. The work presented in this paper is a contribution to the new area of software cybernetics that explores the interplay between software and control.     

A binomial software reliability model based on coverage of structural testing criteria

A new approach to software reliability modeling is discussed where variables indirectly related with software reliability are used to provide additional information for the modeling process. Previous studies, empirical and theoretical evidences, and results from experiments indicate that there is a strong relationship between software reliability and coverage of program elements required to be exercised by structural testing criteria. This paper develops a binomial type coverage-based software reliability model through the definition of a coverage-based failure rate function. The Binomial software reliability Model Based on Coverage—BMBC—is proposed and discussed. In the BMBC test data between failures is used instead of time as independent variable; the model was assessed with test data from a real application, making use of the following structural testing criteria: all-nodes, all-edges, and potential-uses—a data-flow based family of testing criteria. The results from our experiments have shown that our modeling approach has some advantages over some traditional reliability models and points to a very promising research direction in software reliability.