面向全生命周期的装备软件可靠性管理模型

针对装备软件的全生命周期,提出一种软件可靠性管理模型。详细讨论在不同阶段军方的管理活动及所需要的管理方法。这些方法涵盖了装备软件研制过程中的主要可靠性管理活动,同时对支持这些活动所必须的预计、评估模型给出参考建议。所提出的管理模型为军方实施装备软件的可靠性管理提供了有益参考。     

面向服务架构软件实现前的可靠性评价方法

为了在软件实现前评估其可靠性,针对基于面向服务架构(SOA)设计的软件提出了一种可靠性评价方法：用OWL-S描述软件的需求和设计信息,利用Maude为OWL-S过程模型的控制结构定义形式化语义,使用分布函数构建软件的操作剖面,在Maude中增加软件的操作剖面信息和体系结构信息如何参与可靠度计算的描述,在Maude系统的支持下,通过重写得到软件的可靠度,并基于此方法设计开发了一个软件可靠性预计工具——SRPT。所提出的软件可靠性评价方法综合考虑了数据流、控制流、构件和软件操作剖面信息以及体系结构信息对软件可靠性的影响,能够在软件实现前根据软件设计预测其可靠度,为软件的开发设计提供了工程指导。     

火炮火控系统软件可靠性定量评估方法研究

火炮火控系统软件的可靠性直接决定着火炮战技性能的发挥．软件可靠性模型是定量评估软件可靠性的技术基础。通过对软件可靠性概念和软件可靠性模型的分析研究。提出了综合使用Nelson模型和硬一软件复合系统结构模型的可靠性定量评估方法．该方法可以综合两种模型的优点,实现对火炮火控系统软件可靠性的有效评估。     

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.     

基于率的构件软件可靠性过程仿真

与传统的基于模型的构件软件可靠性分析方法相比,基于率的仿真方法由于可以灵活地跟踪软件动态失效过程,近年来开始用于分析构件软件的可靠性过程.但是,目前已经提出的仿真方法对构件软件测试中的故障排除过程做了过分简化的假设,而未能描述软件系统实际的可靠性过程.针对这个问题,提出了一种仿真方法.该方法采用一个混合排队模型建模故障排除过程,其中考虑到了排错策略和排错资源的局限性问题.在此基础上开发出仿真过程,实现对构件软件可靠性过程的仿真.实验结果表明了该仿真方法的有效性.     

电子政务软件可靠性评测方法初探

电子政务已经成为政府工作自动化和智能化的重要手段。近年来,中国电子政务软件市场获得了前所未有的发展机遇。随着电子政务软件的飞速发展,软件可靠性成为了建设电子政务的重要指标。软件可靠性测试是保证软件可靠性的有效方法。目前,国内对于电子政务的可靠性研究才刚刚起步,其可靠性测试一般都交给第三方机构。分析当前电子政务软件的可靠性测试特点,基于Musa和Nelson两种可靠性模型提出了一种电子政务软件的可靠性评测方法,从可靠性的评估测试和验证测试两方面具体分析阐述了方法的流程,并使用工具实现。最后用具体案例对方法进行了分析说明。     

基于SCPN的软件可靠性建模与分析

针对软件动态行为复杂难以建模,且可靠性难以评估的问题,提出一种基于随机有色Petri网SCPN(Stochastic Colored Petri Net)的软件可靠性建模与分析方法。在建立软件可靠性分析的元结构模型的基础上,分别建立软件可靠性分析的串联结构模型和并联结构模型,有效地描述了软件的静态结构和动态行为。以某工厂采购系统为目标系统,以Time NET4.0为平台,建立其基于SCPN的软件可靠性分析模型,仿真验证了所提方法的正确性和有效性。该方法可以为软件可靠性的早期评估提供理论指导。     

软件可靠性的模糊综合评估模型

文章通过对软件可靠性因素的定义和分析,提出了软件可靠性的综合评估指标体系。在计算软件可靠性因素对软件可靠性影响程度的基础上,实现了软件可靠性的定性评估。该模型改变了通常把软件视为“黑箱”来进行可靠性评估的方法,并起到了对传统模型估计结果的检验和修正的作用。     

软件可靠性分析、测试与评估工具--SRATE介绍

软件可靠性分析、测试及评估工具(SRATE)是一个集软件可靠性分析、测试及评估于一体的软件工具。该工具支持多种测试策略下的软件自动化测试及评估试验,包括随机测试策略、自适应测试策略等。该工具还集成了包括欧洲航天局的space软件、浙大CAD&CG国家重点实验室的Intra3D构件库在内的多个典型被测对象。根据工具接口要求可以方便的添加新的测试策略和测试对象。具有自动化程度高、通用性强、配置灵活、易于扩展的特点,是进行软件可靠性分析研究工作的有力工具。     

面向对象分布式软件可靠性评估模型研究

针对面向对象的分布式大型软件的可靠性评估提供了一种较为可行的模型和方法,分析了面向对象分布式软件的复杂性度量因素对可靠性的影响、软件过程能力对于可靠性的影响.提出了使用支持向量回归分析方法解决现代软件可靠性评估问题,并利用Matlab和SVM工具箱对算法进行了具体实现,说明了该方法的可行性.     

基于构件影响因子的软件可靠性评估方法

为提高构件式软件系统可靠性评估的准确性,使软件系统的优化效率得到提高,提出一种基于构件影响因子的软件可靠性评估方法.基于构件式软件系统具有的复杂网络特性,使用引入构件转移概率的加权PageRank算法评估构件的影响因子,将构件的影响因子引入到离散时间马尔科夫链的可靠性评估模型中,评估软件系统的可靠性.实验结果表明,该方...     

The reliability estimation, prediction and measuring of component-based software

Reliability is a key driver of safety-critical systems such as health-care systems and traffic controllers. It is also one of the most important quality attributes of the systems embedded into our surroundings, e.g. sensor networks that produce information for business processes. Therefore, the design decisions that have a great impact on the reliability of a software system, i.e. architecture and components, need to be thoroughly evaluated. This paper addresses software reliability evaluation during the design and implementation phases; it provides a coherent approach by combining both predicted and measured reliability values with heuristic estimates in order to facilitate a smooth reliability evaluation process. The approach contributes by integrating the component-level reliability evaluation activities (i.e. the heuristic reliability estimation, model-based reliability prediction and model-based reliability measuring of components) and the system-level reliability prediction activity to support the incremental and iterative development of reliable component-based software systems. The use of the developed reliability evaluation approach with the supporting tool chain is illustrated by a case study. The paper concludes with a summary of lessons learnt from the case studies.     

遗传优化支持向量机的软件可靠性预测模型

软件可靠性预测在软件开发的早期就能预测出哪些模块有出错倾向。提出一种改进的支持向量机来进行软件可靠性预测。针对支持向量机参数难选择的问题,将遗传算法引入到支持向量机的参数选择中,构造基于遗传算法优化支持向量机的软件可靠性预测模型,并用主成分分析的方法对软件度量数据进行降维,通过仿真实验,证明该模型比支持向量机、BP神经网络、分类回归树和聚类分析等预测模型具有更高的预测精度。     

Survey of reliability and availability prediction methods from the viewpoint of software architecture

Many future software systems will be distributed across a network, extensively providing different kinds of services for their users. These systems must be highly reliable and provide services when required. Reliability and availability must be engineered into software from the onset of its development, and potential problems must be detected in the early stages, when it is easier and less expensive to implement modifications. The software architecture design phase is the first stage of software development in which it is possible to evaluate how well the quality requirements are being met. For this reason, a method is needed for analyzing software architecture with respect to reliability and availability. In this paper, we define a framework for comparing reliability and availability analysis methods from the viewpoint of software architecture. Our contribution is the comparison of the existing analysis methods and techniques that can be used for reliability and availability prediction at the architectural level. The objective is to discover which methods are suitable for the reliability and availability prediction of today’s complex systems, what are the shortcomings of the methods, and which research activities need to be conducted in order to overcome these identified shortcomings. The comparison reveals that none of the existing methods entirely fulfill the requirements that are defined in the framework. The comparison framework also defines the characteristics required of new reliability and availability analysis methods. Additionally, the framework is a valuable tool for selecting the best suitable method for architecture analysis. Furthermore, the framework can be extended and used for other evaluation methods as well.     

RELIABILITY PREDICTION OF IMPERFECT SWITCHING SYSTEMS SUBJECT TO WEIBULL FAILURES

Reliability prediction plays a very important role in system design and evaluation. In order to accurately predict the system reliability, one should consider the system configuration and the failure distribution of its components. This paper discusses the imperfect switching system with one component in an active state and n spares in a standby state. When the operating component breaks down, the switch detects the failure via the sensor and the defective component is replaced with a functional spare, so the system can resume operation. The Weibull distribution is one of the most flexible failure distributions which is widely used because it can adequately describe the reliability behavior during the lifetime of present day components/systems. This paper assumes the operating components follow Weibull failures, but the spares, sensor and switch failures follow an exponential distribution. In addition, three assumptions are made with regard to its switch failures: (i) under the energized condition, (ii) under the failing-open condition, and (iii) under the failing-closed condition. Due to the intractability of the Weibull distribution in imperfect switching models, it is difficult to solve the multiple integration involved analytically. Therefore, a numerical integration method using Simpson's rule was selected as a tool to address the problem of multiple integration for the Weibull distribution. A recursive algorithm is developed for the reliability prediction of a series system with m imperfect switching sub-systems subject to Weibull failures. Finally, a sensitivity analysis is performed on the two parameters of the Weibull distribution, on the effect of spare addition, as well as different failing conditions (switch and sensor) on system reliability. A numerical example is also given to explain and demonstrate the practical application of the developed reliability prediction models.     

The Palladio component model for model-driven performance prediction

One aim of component-based software engineering (CBSE) is to enable the prediction of extra-functional properties, such as performance and reliability, utilising a well-defined composition theory. Nowadays, such theories and their accompanying prediction methods are still in a maturation stage. Several factors influencing extra-functional properties need additional research to be understood. A special problem in CBSE stems from its specific development process: Software components should be specified and implemented independently from their later context to enable reuse. Thus, extra-functional properties of components need to be specified in a parametric way to take different influencing factors like the hardware platform or the usage profile into account. Our approach uses the Palladio component model (PCM) to specify component-based software architectures in a parametric way. This model offers direct support of the CBSE development process by dividing the model creation among the developer roles. This paper presents our model and a simulation tool based on it, which is capable of making performance predictions. Within a case study, we show that the resulting prediction accuracy is sufficient to support the evaluation of architectural design decisions.     

软硬件综合AADL可靠性建模及分析方法

目前嵌入式系统广泛应用于航空电子、远程医疗、汽车电子等具有高可靠性要求的系统中。随着嵌入式系统的复杂度越来越高,为了保障系统的高可靠性需求,需要在系统开发的早期设计阶段对系统的可靠性进行分析评估,以提高系统的开发效率。嵌入式系统中软件、硬件功能的失效都会对系统可靠性产生影响,而AADL的可靠性模型缺乏对硬件构件错误的影响及传播机制进行刻画分析的能力。本文综合考虑软、硬件错误发生失效后对系统可靠性的影响,提出了一种面向系统架构级别的软硬件综合可靠性分析方法。该方法基于电子电路设计中事务级建模方法,扩展了AADL事务级错误模型的语法和语义,来支持AADL对硬件构件错误传播的硬件功能行为建模,在此基础上,利用AADL模型实例化机制实现对嵌入式系统可靠性建模,刻画了错误行为在硬件构件之间、软硬件构件之间的传播与影响。同时,定义了AADL硬件构件事务级错误模型到广义随机Petri网模型的映射规则,实现了系统软、硬件综合的可靠性行为仿真计算模型组合,支持嵌入式系统的软硬件综合可靠性分析。论文开发了软硬件综合可靠性建模与分析工具原型,并以某型飞机空气增压系统为例,在航空电子系统架构设计中进行尝试,验证了该方法在复杂嵌入式系统设计中进行软硬件综合可靠性分析的可行性与优越性。     

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.     

冗余组合导航系统的软件设计及可靠性分析

提出了冗余组合导航应用软件的实用设计方法，当组合导航应用软件中多个任务模块采用N文本法和恢复块法进行冗余设计时，给出了含有容错模块的软件系统的可靠性的评价模型及计算方法。     

基于体系结构的软件可靠性参数早期预测

在对组成软件系统的组件间关系进行分析的基础上,提出了基于组件间关系的软件可靠性的数学模型,该模型给出了在已知组件的可靠性和平均无故障运行时间的基础上计算系统可靠性的方法。通过各组件对系统可靠性的影响分析,给出了改善系统可靠性的方案。