A complete approach for CIM modelling and model formalising

ContextComputation Independent Model (CIM) as a business model describes the requirements and environment of a business system and instructs the designing and development; it is a key to influencing software success. Although many studies currently focus on model driven development (MDD); those researches, to a large extent, study the PIM-level and PSM-level model, and few have dealt with CIM-level modelling for case in which the requirements are unclear or incomplete.ObjectiveThis paper proposes a CIM-level modelling approach, which applies a stepwise refinement approach to modelling the CIM-level model starting from a high-level goal model to a lower-level business process model. A key advantage of our approach is the combination of the requirement model with the business model, which helps software engineers to define business models exactly for cases in which the requirements are unclear or incomplete.MethodThis paper, based on the model driven approach, proposes a set of models at the CIM-level and model transformations to connect these models. Accordingly, the formalisation approach of this paper involves formalising the goal model using the category theory and the scenario model and business process model using Petri nets.ResultsWe have defined a set of metamodels and transformation rules making it possible to obtain automatically a scenario model from the goal model and a business process model from the scenario model. At the same time, we have defined a mapping rule to formalise these models. Our proposed CIM modelling approach and formalisation approach are implemented with an MDA tool, and it has been empirically validated by a travel agency case study.ConclusionThis study shows how a CIM modelling approach helps to build a complete and consistent model at the CIM level for cases in which the requirements are unclear or incomplete in advance.     

面向软件系统的指令时序建模与分析方法

软件指令时序调度是实时软件系统运行的基本问题,如何识别出实时系统中的关键任务,并对其进行及时调度和处理则是解决这一基本问题的关键。应用企业过程建模原理,构造了实时系统的软件过程时序模型,并基于SADT模型,提出了一个基于CPU时间和带宽分配的指令活动模型TB-SADT。引入合成数的概念以求解不确定性软件过程关键路径。针对软件过程模型的控制结构,考虑CPU时间和通信时间的分配,探讨模型中各活动之间时序调度问题。     

基于线性规划理论的软件过程控制模型

在对软件过程度量和分析的基础上,主要针对软件项目的实际工期滞后于计划工期的问题,运用线性规划理论建立了一个软件过程控制模型,并结合实例运用优化软件lingo9.0求得最优解。实验结果表明,该模型可以最大限度地减少后续执行任务的实际工期,确保软件项目在合理的成本范围内交付。     

管理信息系统业务流程的OWL本体模型*

针对传统的开发方式将管理信息系统的业务流程以硬编码形式固化在系统软件中带来的诸多问题,将本体论的思想引入到管理信息系统软件的开发中,将其业务流程抽象成一个合理、机器可读的OWL本体模型,并进一步阐述问题的解决方法.     

Impact of Budget and Schedule Pressure on Software Development Cycle Time and Effort

As excessive budget and schedule compression becomes the norm in today's software industry, an understanding of its impact on software development performance is crucial for effective management strategies. Previous software engineering research has implied a nonlinear impact of schedule pressure on software development outcomes. Borrowing insights from organizational studies, we formalize the effects of budget and schedule pressure on software cycle time and effort as U-shaped functions. The research models were empirically tested with data from a 25 billion/year international technology firm, where estimation bias is consciously minimized and potential confounding variables are properly tracked. We found that controlling for software process, size, complexity, and conformance quality, budget pressure, a less researched construct, has significant U-shaped relationships with development cycle time and development effort. On the other hand, contrary to our prediction, schedule pressure did not display significant nonlinear impact on development outcomes. A further exploration of the sampled projects revealed that the involvement of clients in the software development might have ldquoerodedrdquo the potential benefits of schedule pressure. This study indicates the importance of budget pressure in software development. Meanwhile, it implies that achieving the potential positive effect of schedule pressure requires cooperation between clients and software development teams.     

A transformation‐based approach to testing concurrent programs using UML activity diagrams

Unified Modeling Language (UML) activity diagrams are widely used to model concurrent interaction among multiple objects. In this paper, we propose a transformation‐based approach to generating scenario‐oriented test cases for applications modeled by UML activity diagrams. Using a set of transformation rules, the proposed approach first transforms a UML activity diagram specification into an intermediate representation, from which it then constructs test scenarios with respect to the given concurrency coverage criteria. The approach then finally derives a set of test cases for the constructed test scenarios. The approach resolves the difficulties associated with fork and join concurrency in the UML activity diagram and enables control over the number of the resulting test cases. We further implemented a tool to automate the proposed approach and studied its feasibility and effectiveness using a case study. Experimental results show that the approach can generate test cases on demand to satisfy a given concurrency coverage criterion and can detect up to 76.5% of seeded faults when a weak coverage criterion is used. With the approach, testers can not only schedule the software test process earlier, but can also better allocate the testing resources for testing concurrent applications. Copyright © 2015 John Wiley & Sons, Ltd.     

带时间和资源约束的实例化过程模型验证方法

软件过程的性能是由软件过程模型和软件过程实例化两方面因素决定,如果对软件过程进行了不恰当的实例化,会导致成本超支、进度延期、甚至项目失败．已有的过程描述法不足以分析实例化过程模型,由于没有考虑实例化阶段的时间资源约束,语法结构正确的过程模型并不能保证过程执行的正确性．提出一种带时间和资源约束的实例化过程模型验证方法,为目前已有的s-TRISO／ML建模语言增加时间和资源约束属性,然后提出了从s-TRISO／ML模型转换成时间自动机的转换方法和实现算法,利用已有的分析工具Uppaal对转换得到的时间自动机的性质进行验证,得到一个合理的实例化模型,从而为真实的开发流程提供指导．     

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.     

A methodology for joint optimization for maintenance planning, process quality and production scheduling

Performance of a manufacturing system depends significantly on the shop floor performance. Traditionally, shop floor operational policies concerning maintenance scheduling, quality control and production scheduling have been considered and optimized independently. However, these three aspects of operations planning do have an interaction effect on each other and hence need to be considered jointly for improving the system performance. In this paper, a model is developed for joint optimization of these three aspects in a manufacturing system. First, a model has been developed for integrating maintenance scheduling and process quality control policy decisions. It provided an optimal preventive maintenance interval and control chart parameters that minimize expected cost per unit time. Subsequently, the optimal preventive maintenance interval is integrated with the production schedule in order to determine the optimal batch sequence that will minimize penalty-cost incurred due to schedule delay. An example is presented to illustrate the proposed model. It also compares the system performance employing the proposed integrated approach with that obtained by considering maintenance, quality and production scheduling independently. Substantial economic benefits are seen in the joint optimization.     

基于偏差分析的航空装备软件费用控制方法

针对航空装备软件费用控制与管理问题,提出了一种基于偏差分析的费用控制策略,给出了重大偏差标准设定方法,将挣值管理引入到航空装备软件费用监控中,解决了软件费用与进度的控制问题。研究结果表明,基于挣值管理的方法可准确掌握项目费用和进度的实施情况,当费用或进度偏离计划时,能够及时发现项目研发中存在的问题并采取策略进行调整,有效实现了软件费用和进度的监控与管理。     

软件项目的风险评价模型

软件风险的控制在当今软件开发过程中显得越来越重要,而软件评价的好坏直接影响到管理者对风险的管理。该文提出了一个三级风险评价体系,并基于该体系提出了一种定量风险评价模型。该模型可以预测各风险发生的可能性以及分别计算出各种风险对进度、成本、范围和质量的综合影响。     

Hammerstein-Wiener nonlinear model based predictive control for relative QoS performance and resource management of software systems

Runtime management of Quality of Service (QoS) performance and resource provisioning is a vital issue in shared resource software environments. A useful performance management technique for such software systems is the relative guarantee feedback control scheme. The existing approaches for this class of control systems are mainly based on off-line linear or on-line model identification and control techniques, which tend to have performance issues in the presence of nonlinearities induced by this scheme. Instead of using such modeling techniques, this paper proposes a new approach for QoS performance management and resource provisioning by using an off-line identification of Hammerstein and Wiener nonlinear block structural model. Using the characteristic structure of the nonlinear model, a predictive feedback controller based on a gain schedule technique is incorporated in the design to achieve the performance objectives. The proposed approach is validated using experiments based on a prototype, demonstrating superior runtime QoS performance management and resource provisioning in a complex software system.     

Control Flow Regeneration for Software Pipelined Loops with Conditions

A new intermediate representation for software pipelined loops with conditions is proposed in the paper. The representation allows separation of operations from different paths and their conditional, as well as speculative scheduling, including speculative computation of conditions. An algorithm that transforms the representation into the executable code is presented. The algorithm uses the notion of finite automata to represent the execution of separate paths as threads of control that are canceled or approved by operations that actually compute the conditions. The approach may be used in conjunction with different scheduling techniques to reconstruct the control flow graph from the final schedule directly. It inherently solves the problems of overlapped predicate lifetimes and speculation. The approach provides also a novel formal model for loop execution.     

Dynamic model for the system testing process

The approach for estimating and controlling the software testing effort presented in this paper is based on the theory of dynamical systems. The system testing process is modeled by a dynamical system to better understand its behaviour and to assist project and test managers in planning and tracking effort needs.The proposed model is based on worktime effort measurement and has been applied on three industrial software development projects data. In comparison to other models of the literature the worktime based system testing model describes the behaviour of the process more adequately. Consequently, decisions about the duration of system testing can be supported. Previous models from reliability modelling were selected for comparison. However, the emphasis here is placed on industrial experience on effort tracking and control.     

一种支持MDA的模型转换方法

平台无关模型(PIM)到平台有关模型(PSM)的转换是模型驱动体系结构(MDA)中的关键技术,但目前还没有针对该转换的有效的解决方案。从软件工程的实施出发,以抽象代数理论为基础,同时考虑建模元素的语法结构和语义特性,该文提出了一种基于体系结构映射的、可支持模型间自动转换的方法。该方法充分利用软件体系结构在软件开发各阶段间保持的良好可追踪性,使其同时成为系统分析和模型转换的基础。以J2EE目标平台为例说明了该方法的应用。     

构件系统建模及其动态演化一致性验证方法

基于构件的软件开发已成为软件开发的主流方法,但针对构件系统动态演化后的一致性保持问题,目前尚缺乏统一的标准,为此提出一种验证构件系统动态演化一致性的方法。首先,应用进程代数构造构件模型,并在此基础上得到粗粒度的构件系统模型;然后,根据构件系统模型及其状态的变化,提出构件系统外部行为提取算法,并基于弱互模拟理论定义构件系统动态演化一致性的验证准则;最后,提取演化前后构件系统的行为,并将其转换成便于Pi演算自动工具MWB(Mobility Workbench)识别的格式,以进行行为一致性验证。案例研究表明,该方法是可行且有效的。     

基于遗传算法的嵌入式软件WCSD检测方法

在资源受限的嵌入式系统中,为了降低嵌入式软件最大堆栈深度（Worst-Case-Stack Depth,WCSD）的检测误差,从而确定系统内存容量,通过详细分析堆栈使用原因和中断类型,建立中断调度模型,提出基于遗传算法的WCSD动态检测方法以更加准确地指导嵌入式硬件设计和软件开发。基于嵌入式软件全数字仿真平台完成实验,对该模型和方法加以验证。实验结果表明该方法可测得较准确的软件堆栈深度上限,有助于降低内存开销和提高系统的可信度。     

软件项目进度风险的定量分析方法

软件项目超期仍然是业界的一个普遍现象,进度延期可能直接导致项目质量下降、费用超支甚至失败,因此项目执行过程中对于进度的风险控制至关重要。从定量分析的角度探讨项目进度管理的风险管理方法,并对3种主要的进度管理方法和模型—PERT/CPM方法、关键链方法、事件链方法—进行了调研和对比。其中,事件链是近年来新提出的一种针对风险事件进行建模和分析的方法,为进一步研究有效的进度风险管理控制方法和技术提供了新的思路和视角。     

软件开发中的用例分析技术

用例技术是通过用例、参与者与用例以及用例之间的关系来描绘系统外在需求的一种方法。作为UML(统一建模语言)的一种重要表示法，用例分析方法在软件开发过程中占据着重要的地位。正确使用用例分析方法有助于项目的需求分析、体系结构设计、进度安排、测试和验证。文中简要介绍了增量／迭代式软件过程，通过实例探讨了软件开发中如何使用用例分析技术，包括项目风险分析、确定系统边界、细化事件流、图形化用例以及用例归档技术，从而为获取用例模型提供了有效的方法和途径。     

一种基于领域适配的跨项目软件缺陷预测方法

软件缺陷预测旨在帮助软件开发人员在早期发现和定位软件部件可能存在的潜在缺陷,以达到优化测试资源分配和提高软件产品质量的目的.跨项目缺陷预测在已有项目的缺陷数据集上训练模型,去预测新的项目中的缺陷,但其效果往往不理想,其主要原因在于,采样自不同项目的样本数据集,其概率分布特性存在较大差异,由此对预测精度造成较大影响.针对此问题,提出一种监督型领域适配（domain adaptation）的跨项目软件缺陷预测方法.将实例加权的领域适配与机器学习的预测模型训练过程相结合,通过构造目标项目样本相关的权重,将其施加于充足的源项目样本中,以实例权重去影响预测模型的参数学习过程,将来自目标项目中缺陷数据集的分布特性适配到训练数据集中,从而实现缺陷数据样本的复用和跨项目软件缺陷预测.在10个大型开源软件项目上对该方法进行实证,从数据集、数据预处理、实验结果多个角度针对不同的实验设定策略进行分析;从数据、预测模型以及模型适配层面分析预测模型的过拟合问题.实验结果表明,该方法性能优于同类方法,显著优于基准性能,且能够接近和达到项目内缺陷预测的性能.