可信软件非功能需求形式化表示与可满足分析

可信软件的可信性由其功能需求和非功能需求共同来体现,其中,非功能需求的实现是可信软件获得用户对其行为实现预期目标能力的信任程度的客观依据.针对可信软件的重要性以及对可信软件的迫切需求,在可信软件的早期需求工程阶段,提出可信软件非功能需求驱动的过程策略选取方法.首先,对可信软件需求进行定义,提出由功能需求和非功能需求中的可信关注点构成可信需求,非可信关注点的非功能需求则定义为软目标,用于表达质量需求,基于模糊集合论和信息熵对可信软件非功能需求进行排序并获取可信关注点和软目标.在此基础上,提出可信软件非功能需求驱动的过程策略选取方法.传统的软件早期需求工程阶段的目标是为了获取满足需求的技术及设计决策,与此不同,本文对可信软件非功能需求进行分析的目标是获取过程策略,从过程角度解决可信软件生产问题.由于非功能需求间复杂的相关关系,尤其是因为存在冲突关系,故提出了基于可满足性问题求解方法推理过程策略的方法,选取满足可信软件非功能需求的过程策略.最后,通过第三方可信认证中心软件的案例,说明所提出方法的可行性.     

Die SIKOSA-Methodik

The SIKOSA method addresses the consistency of quality assuring methods in software engineering processes. To support an industrial business software production a new consistent and quality-oriented method was developed. Regarding business processes, which have to be supported, functional and non-functional requirements of business software are specified and transferred into automated test cases and test data.     

可信软件非功能需求可满足性经济学方法分析

针对软件可信性的重要性以及非功能需求的策略选取对软件可信性的影响,提出了一种在早期需求工程阶段将用于辅助决策的经济学和需求工程相结合的方法,并提出了可信软件非功能需求可满足性的策略选取框架,以辅助策略选取。首先,对功能需求及经济学方法概念进行了定义和转换,例如,将软件开发过程中的非功能需求看作经济学生产过程中的生产要素、软件的利益相关者看作生产过程中的生产者等;并定义了非功能需求分解模型。在此基础上,基于模糊集合论和信息熵对软件非功能需求进行模糊排序从而获取利益相关者的关键非功能需求,并利用经济学中生产过程的相关方法计算使用策略的可信性效益,辅助策略的选取。以移动基础维护管理平台为例,使用提出的方法,说明了所提方法的可行性。     

软件非功能需求权衡代价

软件非功能需求的实现涉及软件质量这一重要问题,非功能需求的满足程度,直接影响软件质量的满足程度.针对一直以来对软件质量的一贯重视以及软件非功能需求权衡的重要性,借鉴微观经济学领域的生产理论、替代弹性原理和线性规划方法,提出了软件非功能需求权衡代价分析方法并开发了辅助工具.首先,对项目组前期完成的可信软件非功能需求可满足性分析方法进行改进,提出了利益相关者通过协商获取非功能需求评估数据的方法,建立了非功能需求本体概念并构建本体知识库;针对实现非功能需求的策略,使用前期已完成的策略推理方法,对推理产生矛盾的策略提出权衡代价分析方法;通过分析策略实施代价,为软件开发及演化提供具有实际可操作的权衡决策依据,从更加符合产业化需要的角度解决软件非功能需求权衡问题;最后,基于可信第三方认证中心软件案例的维护及演化需要,对推理出矛盾的策略进行权衡代价分析,并给予决策建议,说明所提出方法的可行性.     

一种建模软件体系结构非功能属性的方法

非功能属性的处理一直是困扰着研究人员和实践者的难题.针对体系结构设计阶段早期,提出一种建模非功能属性的方法.该方法利用面向方面软件开发中的关注点多维分离原理,提出建模软件体系结构的"1+X"模型,并在此基础上进一步划分体系结构非功能属性的维度,归纳各个维度上的关注点,利用XML对维度和关注点进行规约.该模型为后续设计面向方面的软件体系结构奠定了基础,为体系结构设计人员提供了方法支持,而且该成果可以直接用于不同领域内的软件体系结构设计.     

中文非功能需求描述的识别与分类方法研究

非功能需求描述系统质量相关的属性,是软件设计决策的重要依据和评估标准.与功能需求的描述相比,非功能需求描述通常比较分散,且往往是隐含的.当采集到的需求原始描述内容较多时,逐一进行人工判别和整理需要耗费大量的时间和精力.针对中文自然语言描述的需求文本,提出了自动化的非功能需求识别和分类方法.其中,识别过程旨在从文本中提取出可能包含非功能需求的语句,尽可能地缩小人工检查的范围.分类过程则进一步将包含非功能需求的语句划分到性能、可靠性、可用性、安全性、可维护性这五大类非功能需求类型之中.分类训练和实验测试基于课题组工作项目整理的实验数据集进行,最终,基于一个工业界的实际应用案例数据,验证了方法的有效性.     

基于特征组合的软件需求建模

需求建模在需求工程中起着重要的作用。为了提高软件需求建模的效率和质量,提出一种基于特征组合的软件需求建模方法。首先,将特征分为功能性特征和非功能性特征;其次,形式化定义功能性特征的各个部件,包括原子功能性特征和复合功能性特征;第三,把功能性特征之间的特征组合抽象为特征运算,并提出了23条特征运算的公理;第四,形式化定义非功能性特征并通过其作用域把功能性特征和非功能性特征统一为软件需求模型;最后,给出了基于特征组合的软件需求建模过程。     

Toward automated feature model configuration with optimizing non-functional requirements

ContextA software product line is a family of software systems that share some common features but also have significant variabilities. A feature model is a variability modeling artifact, which represents differences among software products with respect to the variability relationships among their features. Having a feature model along with a reference model developed in the domain engineering lifecycle, a concrete product of the family is derived by binding the variation points in the feature model (called configuration process) and by instantiating the reference model.ObjectiveIn this work we address the feature model configuration problem and propose a framework to automatically select suitable features that satisfy both the functional and non-functional preferences and constraints of stakeholders. Additionally, interdependencies between various non-functional properties are taken into account in the framework.MethodThe proposed framework combines Analytical Hierarchy Process (AHP) and Fuzzy Cognitive Maps (FCM) to compute the non-functional properties weights based on stakeholders’ preferences and interdependencies between non-functional properties. Afterwards, Hierarchical Task Network (HTN) planning is applied to find the optimal feature model configuration.ResultOur approach improves state-of-art of feature model configuration by considering positive or negative impacts of the features on non-functional properties, the stakeholders’ preferences, and non-functional interdependencies. The approach presented in this paper extends earlier work presented in [1] from several distinct perspectives including mechanisms handling interdependencies between non-functional properties, proposing a novel tooling architecture, and offering visualization and interaction techniques for representing functional and non-functional aspects of feature models.Conclusionour experiments show the scalability of our configuration approach when considering both functional and non-functional requirements of stakeholders.     

Software architecture correctness

Software quality stems from many factors, including implementation decisions, software architecture, and requirements. We focus on software architecture, which can enable or inhibit many of a software system's qualities. Because the cost of addressing quality concerns is a function of how late you address them (the later, the more costly), addressing them in the architectural or requirements phase makes sense     

A comparative study of many-objective evolutionary algorithms for the discovery of software architectures

During the design of complex systems, software architects have to deal with a tangle of abstract artefacts, measures and ideas to discover the most fitting underlying architecture. A common way to structure such complex systems is in terms of their interacting software components, whose composition and connections need to be properly adjusted. Along with the expected functionality, non-functional requirements are key at this stage to guide the many design alternatives to be evaluated by software architects. The appearance of Search Based Software Engineering (SBSE) brings an approach that supports the software engineer along the design process. Evolutionary algorithms can be applied to deal with the abstract and highly combinatorial optimisation problem of architecture discovery from a multiple objective perspective. The definition and resolution of many-objective optimisation problems is currently becoming an emerging challenge in SBSE, where the application of sophisticated techniques within the evolutionary computation field needs to be considered. In this paper, diverse non-functional requirements are selected to guide the evolutionary search, leading to the definition of several optimisation problems with up to 9 metrics concerning the architectural maintainability. An empirical study of the behaviour of 8 multi- and many-objective evolutionary algorithms is presented, where the quality and type of the returned solutions are analysed and discussed from the perspective of both the evolutionary performance and those aspects of interest to the expert. Results show how some many-objective evolutionary algorithms provide useful mechanisms to effectively explore design alternatives on highly dimensional objective spaces.     

Knowledge based quality-driven architecture design and evaluation

Modelling and evaluating quality properties of software is of high importance, especially when our every day life depends on the quality of services produced by systems and devices embedded into our surroundings. This paper contributes to the body of research in quality and model driven software engineering. It does so by introducing; (1) a quality aware software architecting approach and (2) a supporting tool chain. The novel approach with supporting tools enables the systematic development of high quality software by merging benefits of knowledge modelling and management, and model driven architecture design enhanced with domain-specific quality attributes. The whole design flow of software engineering is semi-automatic; specifying quality requirements, transforming quality requirements to architecture design, representing quality properties in architectural models, predicting quality fulfilment from architectural models, and finally, measuring quality aspects from implemented source code. The semi-automatic design flow is exemplified by the ongoing development of a secure middleware for peer-to-peer embedded systems.     

Software performance tuning of software product family architectures: Two case studies in the real-time embedded systems domain

Software performance is an important non-functional quality attribute and software performance evaluation is an essential activity in the software development process. Especially in embedded real-time systems, software design and evaluation are driven by the needs to optimize the limited resources, to respect time deadlines and, at the same time, to produce the best experience for end-users. Software product family architectures add additional requirements to the evaluation process. In this case, the evaluation includes the analysis of the optimizations and tradeoffs for the whole products in the family. Performance evaluation of software product family architectures requires knowledge and a clear understanding of different domains: software architecture assessments, software performance and software product family architecture. We have used a scenario-driven approach to evaluate performance and dynamic memory management efficiency in one Nokia software product family architecture. In this paper we present two case studies. Furthermore, we discuss the implications and tradeoffs of software performance against evolvability and maintenability in software product family architectures.     

The socio-economics of software architecture

The paper argues that strategic decisions about software architectures need to be based on a social and economic analysis of which designs are likely to succeed and become accepted by users. Software architecture is increasingly having to take account of customisation, reuse, end-user development and system configuration. The relationship between architecture and end users’ requirements is investigated, to propose a cost-benefit framework to support reasoning about architectural choices from the perspective of end users. The relationships between architectural decisions and non-functional requirements is reviewed, and the impact on architecture is assessed using a case study of developing configurable, semi-intelligent software to support medical researchers in e-science domains.     

软件架构的非功能性需求指标和区域化支持

随着计算机科学技术的发展,越来越多的人把关注的目光投入到了计算机软件领域,而软件构架中的非功能需求凭借其在软件设计过程中的重要地位更是得到了开发人员的重视。该文以非功能需求作为研究对象进行分析,从软件架构的概念谈起,阐述了非功能需求的发展历程,并详细介绍了非功能需求的常见指标,最后提出非功能需求的区域化支持这一概念。     

DMS系统图形绘制软件架构模型的研究与设计

文章简单介绍了文中涉及的统一建模语言UML的概念,论述了配电自动化系统中图形绘制软件主要的功能需求和非功能需求,通过对这些需求的研究和分析,提出了一个基于模型-视图-控制设计模式、符合面向对象思想的图形绘制软件架构模型,详细分析了组成该模型的类,用UML的类图和时序图描述了模型的静态和动态架构,以开发原型系统的方式验证了该模型的合理性和可用性。     

Promoting software quality through a human,social and organisational requirements elicitation process

Human, social and organisational (HSO) factors play a decisive role in software development in terms of determining functional and non-functional characteristics of software products. The significance of these factors is underlined by the need to produce applications that fit nicely in a working setting, supporting the working procedures followed and promoting users' content and productivity. In this context, a new requirements elicitation process is proposed, a part of which utilises a short-scale ethnography analysis. The process introduces specific steps for recording HSO factors based on certain software quality characteristics that are treated as principal components for conducting requirements identification. The output of the process is the HSO document, which can be used in conjunction with the classic requirements document to identify structural and functional aspects of the system.     

Quality-driven architecture development using architectural tactics

This paper presents a quality-driven approach to embodying non-functional requirements (NFRs) into software architecture using architectural tactics. Architectural tactics are reusable architectural building blocks, providing general architectural solutions for common issues pertaining to quality attributes. In this approach, architectural tactics are represented as feature models, and their semantics is defined using the Role-Based Metamodeling Language (RBML) which is a UML-based pattern specification notation. Given a set of NFRs, architectural tactics are selected and composed, and the composed tactic is used to instantiate an initial architecture for the application. The proposed approach addresses both the structural and behavioral aspects of architecture. We describe the approach using tactics for performance, availability and security to develop an architecture for a stock trading system. We demonstrate tool support for instantiating a composed tactic to generate an initial architecture of the stock trading system.     

SMArDT modeling for automotive software testing

Efficient testing is a crucial prerequisite to engineer reliable automotive software successfully. However, manually deriving test cases from ambiguous textual requirements is costly and error-prone. Model-based software engineering captures requirements in structured, comprehensible, and formal models, which enables early consistency checking and verification. Moreover, these models serve as an indispensable basis for automated test case derivation. To facilitate automated test case derivation for automotive software engineering, we conducted a survey with testing experts of the BMW Group and conceived a method to extend the BMW Group's specification method for requirements, design, and test methodology by model-based test case derivation. Our method is realized for a variant of systems modeling language activity diagrams tailored toward testing automotive software and a model transformation to derive executable test cases. Hereby, we can address many of the surveyed practitioners' challenges and ultimately facilitate quality assurance for automotive software.