An automated software reliability prediction system for safety critical software

Software reliability is one of the most important software quality indicators. It is concerned with the probability that the software can execute without any unintended behavior in a given environment. In previous research we developed the Reliability Prediction System (RePS) methodology to predict the reliability of safety critical software such as those used in the nuclear industry. A RePS methodology relates the software engineering measures to software reliability using various models, and it was found that RePS’s using Extended Finite State Machine (EFSM) models and fault data collected through various software engineering measures possess the most satisfying prediction capability. In this research the EFSM-based RePS methodology is improved and implemented into a tool called Automated Reliability Prediction System (ARPS). The features of the ARPS tool are introduced with a simple case study. An experiment using human subjects was also conducted to evaluate the usability of the tool, and the results demonstrate that the ARPS tool can indeed help the analyst apply the EFSM-based RePS methodology with less number of errors and lower error criticality.     

Test-execution-based reliability measurement and modeling for largecommercial software

The paper studies practical reliability measurement and modeling for large commercial software systems based on test execution data collected during system testing. The application environment and the goals of reliability assessment were analyzed to identify appropriate measurement data. Various reliability growth models were used on failure data normalized by test case executions to track testing progress and provide reliability assessment. Practical problems in data collection, reliability measurement and modeling, and modeling result analysis were also examined. The results demonstrated the feasibility of reliability measurement in a large commercial software development environment and provided a practical comparison of various reliability measurements and models under such an environment     

Software complexity and its impact on software reliability

To produce reliable software, its complexity must be controlled by suitably decomposing the software system into smaller subsystems. A software complexity metric is developed that includes both the internal and external complexity of a module. This allows analysis of a software system during its development and provides a guide to system decomposition. The basis of this complexity metric is in the development of an external complexity measure that characterizes module interaction     

Test workload measurement and reliability analysis for large commercial software systems

This paper characterizes the testing environment for large commercial software systems, matches reliability model assumptions with the application environment, examines alternative test workload measurements that capture software usage information during testing, and uses two such measurements, test runs and transactions, as our usage dependent time measurements in reliability modeling. Our previous research using test runs, execution time, and test input information for reliability analysis and improvement is extended to ensure better test workload measurements for reliability assessment and prediction. This paper also identifies conditions under which different test workload measurements are appropriate, and presents reliability modeling results using these measurements in several products developed in the IBM Software Solutions Toronto Laboratory.     

面向CMMI的软件度量分析过程研究与应用

为了辅助软件组织有效实施符合CMMI模型的软件度量过程,提出了一种GREDR过程框架模型,以指导软件度量的目标策划与过程实施。在实际软件项目过程中的应用结果表明：GREDR模型能够提高软件度量过程的系统性与效用。     

Stochastic software testing

This paper presents a method for test case selection that allows a formal approach to testing software. The two main ideas are (1) that testers create stochastic models of software behavior instead of crafting individual test cases and (2) that specific test cases are generated from the stochastic models and applied to the software under test. This paper describes a method for creating a stochastic model in the context of a solved example. We concentrate on Markov models and show how non‐Markovian behavior can be embedded in such models without violating the Markov property.     

嵌入式实时控制系统软件可靠性建模与应用

嵌入式实时控制系统(ERCS)广泛应用于各种控制系统中,其软件不同于普通软件,除满足实时性要求外,可靠性也是相当重要的。首先对嵌入式实时控制系统软件进行形式化抽象定义,然后对不可再分的软件模块进行可靠性建模,并应用Copula函数对软件系统进行建模,最后应用建立的模型,对具体的系统进行了软件可靠性计算。通过实例计算可知,用Copula函数建立的嵌入式实时控制系统软件可靠性模型,考虑了软件各个模块的相依性,进而得到嵌入式实时控制系统软件模块相依的可靠度较各模块独立时有所提高。     

计算机辅助设计软件及其应用分析

计算机辅助设计软件的开发和应用,慢慢取代了原有的手工绘画工具,同时其集二维绘画软件和三维绘画软件于一体,不仅能够提高设计绘画的效率,同时能够将设计人员丰富的设计想象和思维直观的体现出来。本文对现阶段计算机辅助设计软件进行简单概述,并对其应用进行分析,希望对计算机辅助软件应用研究提供一定的参考价值。     

A time/structure based software reliability model

The past 20 years have seen the formulation of numerous analytical software reliability models for estimating the reliability growth of a software product. The predictions obtained by applying these models tend to be optimistic due to the inaccuracies in the operational profile, and saturation effect of testing. Incorporating knowledge gained about some structural attribute of the code, such as test coverage, into the time-domain models can help alleviate this optimistic trend. In this paper we present an enhanced non-homogeneous Poisson process (ENHPP) model which incorporates explicitly the time-varying test-coverage function in its analytical formulation, and provides for defective fault detection and test coverage during the testing and operational phases. It also allows for a time varying fault detection rate. The ENHPP model offers a unifying framework for all the previously reported finite failure NHPP models via test coverage. We also propose the log-logistic coverage function which can capture an increasing/decreasing failure detection rate per fault, which cannot be accounted for by the previously reported finite failure NHPP models. We present a methodology based on the ENHPP model for reliability prediction earlier in the testing phase. Expressions for predictions in the operational phase of the software, software availability, and optimal software release times subject to various constraints such as cost, reliability, and availability are developed based on the ENHPP model. We also validate the ENHPP model based on four different coverage functions using five failure data sets. This revised version was published online in June 2006 with corrections to the Cover Date.     

Predicting software reliability

Critical business applications require reliable software, but developing reliable software is one of the most difficult problems facing the software industry. After the software is shipped, software vendors receive customer feedback about software reliability. However, by then it is too late; software vendors need to know whether their products are reliable before they are delivered to customers. Software reliability growth models help provide that information. Unfortunately, very little real data and models from commercial applications have been published, possibly because of the proprietary nature of the data. Over the past few years, the author and his colleagues at Tandem have experimented with software reliability growth models. At Tandem, a major software release consists of substantial modifications to many products and may contain several million lines of code. Major software releases follow a well defined development process and involve a coordinated quality assurance effort. We applied software reliability modeling to a subset of products for four major releases. The article reports on what was learned     

软件可靠性与硬件可靠性分析及对比

介绍了可靠性的定义和基本概念,分析了软件可靠性和硬件可靠性的区别与联系,讨论了软件可靠性和硬件可靠性这两个领域中的一些基本研究及建模方法。     

蛋白质突变仿真&虚拟筛选系统的开发和应用

筛选因过程复杂造成费钱费时费力,成为定向进化的瓶颈。因此,开发出蛋白质突变仿真&虚拟筛选系统,以部分替代实验筛选,提高筛选效率,具有十分重要的意义。利用对字符串的随机替换来模仿蛋白质序列的突变,通过加权二肽组成、偏最小二乘回归等数学模型对产生的蛋白质序列进行筛选。开发的蛋白质突变仿真&虚拟筛选系统软件,可以部分替代实验筛选。软件在WINDOWS XP及DotNetFramework 2.0下运行稳定,计算速度快,拟合结果良好,基本可以满足数据处理的需要。软件的参数灵活可调,能够输出各种数据,可以方便分析验证,也可与其它软件整合进行数据分析以达到研究目的。     

面向对象软件系统的一种度量方法及其应用

在面向对象系统分析和设计过程中，类的设计质量直接关系到软件系统质量。首先对类之间的关系进行了分析、说明和定义，并分为横向关系和纵向关系，给出了横向关系和纵向关系度量与质量评价，并在此基础上给出了改善类设计质量的方法。     

基于行为的软件测试过程模型及其应用研究

在深入研究各种综合测试技术的基础上,通过对比分析各种主流的测试模型,提出了一种基于行为的软件测试过程模型,包括了测试设计、测试计划、测试执行、测试结果分析和测试重用等活动,把这些测试活动嵌入到软件开发的整个生命周期当中。然后将这种测试模型应用到一个大型的应用程序测试项目(AMP)中,发现这种测试模型在尽早发现Bug和回归测试选择效率上具有较好的测试效果。     

软件体系结构设计技术及其应用

在大规模软件开发的过程中，软件体系结构设计起着举足轻重的作用，用它来指导整个开发过程，可以准确满足需求并充分提高软件系统的重用性和可维护性。结合数据传输工具DataTrans，详细阐述了一种描绘体系结构的标准化方法并阐述了该方法在DataTrans中的应用。     

Software reliability analysis and choice of software reliability criteria

Functional reliability of computer software is considered using fuzzy automaton representation of software systems.Translated from Kibernetika i Sistemnyi Analiz, No. 2, pp. 46–60, March–April, 1992.     

Measuring computer software reliability

Under certain conditions, traditional hypothesis-testing techniques may be used as a management tool by software developers or software purchasers who wish to insure that their packages have some specified reliability level. These conditions are: (1) the existence of independent collections of test data, (2) a way of determining the correctness of processing of these collections, and (3) a way of randomly selecting test data.Two basic approaches have been described. In a fixed sample size test, the user decides on the reliability desired. He can then determine the number of test cases which must be examined and the acceptance/rejection criteria. In a sequential test, the desired reliability level is again pre-determined, but samples are tested one at a time until an accept/reject decision can be made.Experiments with a large amount of error data derived from six separate systems indicate that reliability results derived from these models are consistent with actual reliability figures.Most current acceptance procedures are based on a naive assumption that a large program can be exhaustively tested and delivered in an error-free condition. Because these expectations cannot be fulfilled, the manager of a software development project or the purchaser of a software product is provided with no quantitative information on which to base an acceptance decision and is thus forced to make these decisions based mostly on intuition and his own experience in similar situations. These models allow one to replace these intuition-based decisions with quantitatively-based decisions and thus constitute an important contribution to the science of management of software development efforts.