An Optimal Solution for Test Case Generation Using ROBDD Graph and PSO Algorithm

Software testing is one of the most important techniques to examine the behavior of the software products to assure their quality. An effective and efficient testing approach must balance two important but conflicting requirements. One of them is the accuracy that needs a large number of test cases for testing, and the second one is reducing the time and cost, which requires a few test cases. Even for small software, the number of possible test cases is typically very large, and exhaustive testing is impractical. Hence, selecting appropriate test suite is necessary. Cause–effect graph testing is a common black‐box testing technique, which is equivalently representing Boolean relations between input parameters. However, the other traditional black‐box strategies cannot identify the relations that it may result in loss of some of the important test cases. Although the cause–effect graph is regarded very promising in specification testing, it is observed that most of the proposed approaches using the graph are complex or generate impossible and a large number of test cases. This observation has motivated our research to propose an efficient strategy to generate minimal test suite that simultaneously achieves high coverage of input parameters. To do so, at first, we identify major effects from the cause–effect graph using reduced ordered binary decision diagram (ROBDD). ROBDD makes the related Boolean expression of the graph concise and obtains a unique representation of the expression. Using the ROBDD, it is possible to reduce the size of the generated test suite and to perform testing faster. After that, our proposed method utilizes particle swarm optimization (PSO) algorithm to select the optimal test suite, which covers all pairwise combinations of input parameters. The experimental results show that our approach simultaneously achieves high efficacy and reduces cost of testing by selecting appropriate test cases, respectively, to both test size and coverage size. Also, it outperforms some existing state‐of‐the‐art strategies in the black‐box testing. Copyright © 2015 John Wiley & Sons, Ltd.     

基于SysML模型的需求建模及测试方法

为了将模型驱动测试有效应用于嵌入式系统测试中,本文说明了需求建模方法以及用例生成方法,以及SysML建模语言中状态机图的抽象语法、图元符号和形式化语义,针对性能测试要求,总结了关于状态机模型的性能测试建模方法,并通过实例构建状态机图描述性能需求,建立测试场景分析方法,有效覆盖系统的性能测试类型.经验证,采用基于模型驱动的测试方法能够建立明确系统执行逻辑,构建测试最长路径等场景,保证测试的充分性和覆盖性,提升测试效率和自动化程度.     

Using Scrum and unified modelling language to analyze and design an automatic course scheduling system

This research used a case study methodology to examine large-scale software projects accomplished despite ambiguous customer requirements. This study adopted Scrum as the agile software development method and used unified modelling language (UML) diagrams to enhance design implementation documents and improve the software development process. This study presented how the case company explored a Scrum-based automatic course scheduling system for elementary and secondary schools. Through interviews, the case company incorporated customers’ requirements by using the corresponding UML diagrams, which helped the project team document the software development process and design the functions to satisfy customer demand. Then, the proposed method was introduced to the automatic elementary and secondary school course scheduling system project undertaken by the case company, verifying the feasibility of the proposed method. A few problems arose in the proposed software development process, and remedies were discussed. Software companies could use these results as a reference when implementing a large-scale software project with ambiguous customer requirements.     

Automatic test case generation using unified modeling language (UML) state diagrams

UML is widely accepted and used by industry for modelling and design of software systems. A novel method to automatically generate test cases based on UML state models is presented. In the present approach, the control and data flow logic available in the UML state diagram to generate test data are exploited. The state machine graph is traversed and the conditional predicates on every transition are selected. Then these conditional predicates are transformed and function minimisation technique is applied to generate test cases. The present test data generation scheme is fully automatic and the generated test cases satisfy transition path coverage criteria. The generated test cases can be used to test class as well as cluster-level state-dependent behaviours.     

An EFSM-Based Test Data Generation Approach in Model-Based Testing

Testing is an integral part of software development. Current fast-paced system developments have rendered traditional testing techniques obsolete. Therefore, automated testing techniques are needed to adapt to such system developments speed. Model-based testing (MBT) is a technique that uses system models to generate and execute test cases automatically. It was identified that the test data generation (TDG) in many existing model-based test case generation (MB-TCG) approaches were still manual. An automatic and effective TDG can further reduce testing cost while detecting more faults. This study proposes an automated TDG approach in MB-TCG using the extended finite state machine model (EFSM). The proposed approach integrates MBT with combinatorial testing. The information available in an EFSM model and the boundary value analysis strategy are used to automate the domain input classifications which were done manually by the existing approach. The results showed that the proposed approach was able to detect 6.62 percent more faults than the conventional MB-TCG but at the same time generated 43 more tests. The proposed approach effectively detects faults, but a further treatment to the generated tests such as test case prioritization should be done to increase the effectiveness and efficiency of testing.     

Improved Test Case Selection Algorithm to Reduce Time in Regression Testing

Regression testing (RT) is an essential but an expensive activity in software development. RT confirms that new faults/errors will not have occurred in the modified program. RT efficiency can be improved through an effective technique of selected only modified test cases that appropriate to the modifications within the given time frame. Earlier, several test case selection approaches have been introduced, but either these techniques were not sufficient according to the requirements of software tester experts or they are ineffective and cannot be used for available test suite specifications and architecture. To address these limitations, we recommend an improved and efficient test case selection (TCS) algorithm for RT. Our proposed technique decreases the execution time and redundancy of the duplicate test cases (TC) and detects only modified changes that appropriate to the modifications in test cases. To reduce execution time for TCS, evaluation results of our proposed approach are established on fault detection, redundancy and already executed test case. Results indicate that proposed technique decreases the inclusive testing time of TCS to execute modified test cases by, on average related to a method of Hybrid Whale Algorithm (HWOA), which is a progressive TCS approach in regression testing for a single product.     

Role of Fuzzy Approach towards Fault Detection for Distributed Components

Component-based software development is rapidly introducing numerous new paradigms and possibilities to deliver highly customized software in a distributed environment. Among other communication, teamwork, and coordination problems in global software development, the detection of faults is seen as the key challenge. Thus, there is a need to ensure the reliability of component-based applications requirements. Distributed device detection faults applied to tracked components from various sources and failed to keep track of all the large number of components from different locations. In this study, we propose an approach for fault detection from component-based systems requirements using the fuzzy logic approach and historical information during acceptance testing. This approach identified error-prone components selection for test case extraction and for prioritization of test cases to validate components in acceptance testing. For the evaluation, we used empirical study, and results depicted that the proposed approach significantly outperforms in component selection and acceptance testing. The comparison to the conventional procedures, i.e., requirement criteria, and communication coverage criteria without irrelevancy and redundancy successfully outperform other procedures. Consequently, the F-measures of the proposed approach define the accurate selection of components, and faults identification increases in components using the proposed approach were higher (i.e., more than 80 percent) than requirement criteria, and code coverage criteria procedures (i.e., less than 80 percent), respectively. Similarly, the rate of fault detection in the proposed approach increases, i.e., 92.80 compared to existing methods i.e., less than 80 percent. The proposed approach will provide a comprehensive guideline and roadmap for practitioners and researchers.     

Test Case Prioritization in Unit and Integration Testing: A Shuffled-Frog-Leaping Approach

Both unit and integration testing are incredibly crucial for almost any software application because each of them operates a distinct process to examine the product. Due to resource constraints, when software is subjected to modifications, the drastic increase in the count of test cases forces the testers to opt for a test optimization strategy. One such strategy is test case prioritization (TCP). Existing works have propounded various methodologies that re-order the system-level test cases intending to boost either the fault detection capabilities or the coverage efficacy at the earliest. Nonetheless, singularity in objective functions and the lack of dissimilitude among the re-ordered test sequences have degraded the cogency of their approaches. Considering such gaps and scenarios when the meteoric and continuous updations in the software make the intensive unit and integration testing process more fragile, this study has introduced a memetics-inspired methodology for TCP. The proposed structure is first embedded with diverse parameters, and then traditional steps of the shuffled-frog-leaping approach (SFLA) are followed to prioritize the test cases at unit and integration levels. On 5 standard test functions, a comparative analysis is conducted between the established algorithms and the proposed approach, where the latter enhances the coverage rate and fault detection of re-ordered test sets. Investigation results related to the mean average percentage of fault detection (APFD) confirmed that the proposed approach exceeds the memetic, basic multi-walk, PSO, and optimized multi-walk by 21.7%, 13.99%, 12.24%, and 11.51%, respectively.     

软件产品黑盒测试的测试用例设计

软件测试是为了发现软件缺陷和错误而执行的过程.传统的穷举测试,受到时间、费用和人工等条件的限制,实施起来是不现实的.为了节省时间和资源,提高测试效率,从大量的可用测试用例中精心选取了少量的测试数据,使得采用这些测试数据能够达到最佳的测试效果,可以高效地发现软件中隐藏的错误和缺陷.     

网络印刷服务平台功能模型的分析及建立

对网络印刷服务平台的功能需求进行了分析,并利用UML建模法为其建立了功能模型。分别选取UML用例图描述了网络印刷服务平台的静态功能,以UML时序图描述了网络印刷服务平台的动态业务流程,二者共同构成网络印刷服务平台的功能模型,为今后网络印刷服务平台的开发提供了依据。     

Theory for classifying equivalences of unified modelling language activity diagrams

Despite the fact that there has been a wide adoption of unified modelling language activity diagrams (UML ADs) for software development, research focusing on the equivalence notions of UML ADs is scarce. To address this area of concern, the author presents a sound theoretical foundation for UML ADs. Through the use of these formal definitions of UML ADs, the author propounds a method which classifies various types of equivalences of UML ADs in a systematic way. The proposed classification, which is the core result of our work, provides a framework that enables the study of the properties and inter-relationships of the equivalences.     

Comparing finite state machine test

To plan testing activities, testers face the challenge of determining a strategy, including a test coverage criterion that offers an acceptable compromise between the available resources and test goals. Known theoretical properties of coverage criteria do not always help and, thus, empirical data are needed. The results of an experimental evaluation of several coverage criteria for finite state machines (FSMs) are presented, namely, state and transition coverage; initialisation fault and transition fault coverage. The first two criteria focus on FSM structure, whereas the other two on potential faults in FSM implementations. The authors elaborate a comparison approach that includes random generation of FSM, construction of an adequate test suite and test minimisation for each criterion to ensure that tests are obtained in a uniform way. The last step uses an improved greedy algorithm.     

Modelling biological behaviours with the unified modelling language: an immunological case study and critique

We present a framework to assist the diagrammatic modelling of complex biological systems using the unified modelling language (UML). The framework comprises three levels of modelling, ranging in scope from the dynamics of individual model entities to system-level emergent properties. By way of an immunological case study of the mouse disease experimental autoimmune encephalomyelitis, we show how the framework can be used to produce models that capture and communicate the biological system, detailing how biological entities, interactions and behaviours lead to higher-level emergent properties observed in the real world. We demonstrate how the UML can be successfully applied within our framework, and provide a critique of UML''s ability to capture concepts fundamental to immunology and biology more generally. We show how specialized, well-explained diagrams with less formal semantics can be used where no suitable UML formalism exists. We highlight UML''s lack of expressive ability concerning cyclic feedbacks in cellular networks, and the compounding concurrency arising from huge numbers of stochastic, interacting agents. To compensate for this, we propose several additional relationships for expressing these concepts in UML''s activity diagram. We also demonstrate the ambiguous nature of class diagrams when applied to complex biology, and question their utility in modelling such dynamic systems. Models created through our framework are non-executable, and expressly free of simulation implementation concerns. They are a valuable complement and precursor to simulation specifications and implementations, focusing purely on thoroughly exploring the biology, recording hypotheses and assumptions, and serve as a communication medium detailing exactly how a simulation relates to the real biology.     

Bayes approach in RDT using accelerated and long-term life data

A common problem of reliability demonstration testing (RDT) is the magnitude of total time on test required to demonstrate reliability to the consumer’s satisfaction, particularly in the case of high reliability components. One solution is the use of accelerated life testing (ALT) techniques. Another is to incorporate prior beliefs, engineering experience, or previous data into the testing framework. This may have the effect of reducing the amount of testing required in the RDT in order to reach a decision regarding conformance to the reliability specification. It is in this spirit that the use of a Bayesian approach can, in many cases, significantly reduce the amount of testing required.We demonstrate the use of this approach to estimate the acceleration factor in the Arrhenius reliability model based on long-term data given by a manufacturer of electronic components (EC). Using the Bayes approach we consider failure rate and acceleration factor to vary randomly according to some prior distributions. Bayes approach enables for a given type of technology the optimal choice of test plan for RDT under accelerated conditions when exacting reliability requirements must be met. These requirements are given by a hypothetical consumer by two different ways. The calculation of posterior consumer’s risk is demonstrated in both cases.The test plans are optimum in that they take into account Var{λ|data}, posterior risk, E{λ|data}, Median λ or other percentiles of λ at data observed at the accelerated conditions. The test setup assumes testing of units with time censoring.     

航空发动机风扇机匣包容性等效试验与分析方法

针对硬壁机匣包容性问题,提出在发动机研制初期,通过风扇包容机匣等效试验件靶板冲击试验,模拟真实风扇叶片脱落机匣包容性过程,并通过材料高应变率试验拟合机匣材料在高应变率下的本构模型;建立基于简化试验结果的数值仿真模型标定及机匣包容性分析模型修正方法,对风扇叶片脱落机匣包容性分析模型进行标定,建立高精度风扇机匣包容性仿真预测模型,用于风扇叶片脱落适航取证试验前仿真预测,以提高试验成功率、减少试验次数。通过数值仿真可拟合获得机匣包容厚度与叶片脱落载荷的关系,为风扇包容机匣设计提供厚度参数输入参考。     

塑料药筒结构设计及吹塑成形工艺

目的解决药筒在射击后退壳故障问题,降低生产成本。方法将钢质药筒改成塑料药筒,并进行了拉伸力学性能检测、合膛性能以及靶场射击试验。结果产品通过了相关性能检测,满足使用要求。结论全面解决了在高膛压条件下射击时,因金属药筒变形而出现半退壳和不退壳状态的故障问题。     

Detecting overlapping use cases

To deal with the complexity of large information systems, the divide-and-conquer policy is usually adopted to capture requirements from a large number of stakeholders: obtain requirements from different stakeholders, respectively, and then put them together to form a full requirement specification. One of the problems induced by the policy is overlapping requirements. A use case driven approach could not avoid overlapping requirements either: it produces overlapping use cases, which are even more harmful, because a use case describes not only inputs and outputs as traditional requirements do, but also the scenarios. Each of the overlapping use cases provides a message sequence to implement the common subgoal. Overlapping use cases not only decrease the maintainability of the requirement specification, but also result in a complicated, confusing and expensive system. To be worse, it is difficult to detect overlapping use cases with existing methods for requirement management. To find out overlapping use cases, a detection approach using sequence diagrams and statecharts is proposed. Evaluation results suggest that practical requirement models do contain overlapping use cases, and the proposed approach is effective in detecting them     

Non-destructive testing of concrete strength: statistical control

Some problems of statistical control of concrete strength in non-destructive testing are considered. The procedures for rejection of gross errors and accounting for the actual law of concrete strength distribution are given. In the non-destructive control, the reliability and accuracy of a test result, f_i, as well as the probability of a specified concrete strength, f′ _c , should be the same as in testing with the use of a standard method (specimen testing). Proceeding from this concept, known acceptance criteria are analysed and those recommended by the author are described. The use of the latter permits a considerable reduction of the consumer's risk. Procedures for specifying a required average strength, f _cr , are also analysed. In the use of the proposed acceptance criteria, the value of f _cr may be reduced in many cases, and hence the cement content may be decreased.     

A critical analysis of plastic flow behaviour in axisymmetric isothermal and Gleeble compression testing

Coupled thermo-mechanical finite element modelling of both isothermal axisymmetric compression and compression testing using the Gleeble thermo-mechanical simulator has been carried out in order to compare the levels of relative stress error which can arise during each test. A Norton-Hoff material model has been used as a basis for evaluating the testing methods and the calculation of the relative error by providing reference stress–strain curves. The errors arise from effects such as interface friction causing non-uniform deformation fields and heat generation in both testing cases and from initial specimen temperature profiles in the case of the Gleeble testing. These errors are shown to be up to approximately 20% and vary throughout the test from positive to negative and are therefore important to consider when processing experimental data.     

Assume-guarantee testing for software components

Integration issues of component-based systems tend to be targeted at the later phases of the software development, mostly after components have been assembled to form an executable system. However, errors discovered at these phases are typically hard to localise and expensive to fix. To address this problem, the authors introduce assume-guarantee testing, a technique that establishes key properties of a componentbased system before component assembly, when the cost of fixing errors is smaller. Assume-guarantee testing is based on the (automated) decomposition of system-level requirements into local component requirements at design time. The local requirements are in the form of assumptions and guarantees that each component makes on, or provides to the system, respectively. Checking requirements is performed during testing of individual components (i.e. unit testing) and it may uncover system-level violations prior to system testing. Furthermore, assume-guarantee testing may detect such violations with a higher probability than traditional testing. The authors also discuss an alternative technique, namely predictive testing, that uses the local component assumptions and guarantees to test assembled systems: given a non-violating system run, this technique can predict violations by alternative system runs without constructing those runs. The authors demonstrate the proposed approach and its benefits by means of two NASA case studies: a safetycritical protocol for autonomous rendez-vous and docking and the executive subsystem of the planetary rover controller K9.