多视点间不一致性的认知推理

需求工程可以认为是一个知识表示,知识获取和知识分析的过程.多视点需求工程就是希望复杂系统中的不同参与者分别从自己的角度出发对预期系统进行描述,从而形成更完备的需求规约.由于多视点方法的这种特性,导致多个涉众有可能对同一问题进行描述,从而形成重叠的需求.这些重叠的需求就是涉众之间的公共知识,对公共知识的不同解释是导致需求规约中不一致问题的根源.本文对基于问题域的多视点需求建模框架进行基于时序认知逻辑的解释和推理,期望达到以下目的:1)使用户陈述的需求更加结构化;2)使用形式化的方法帮助涉众发现那些重叠的需求.     

视点间的不一致性检查和视点集成

需求定义人员常从同的观察角度来定义大型软件系统的需求,从而形成多个部分需求说明（视点）。由于视点之间的相对独立性,多视点的集成是需求工程中一项重要而又困难的研究课题。使用形式化方法来描述视点需求和视点间的关系将使视点集成能自动进行。在此,使用SFSM状态转换图来描述视点需求,并将视点间的关系用谓词的形式表示在状态图中状态转换的卫士条件中,同时在此基础上提出了一种自动合成视点的方法,需求定义人员可以根据状态等价关系与合成后状态图的冲突来检查和解决两个视点之间的不一致性。通过重复视点合成和检查、处理视点间的不一致性这一过程,多个视点可以被集成为整个软件系统的需求说明,应用了一个电话系统的例子说明了此视点需求表示和视点集成方法。使用此方法,视点集成过程可以自动完成,同时还可以在一定程度上引导需求定义人员检查和解决视点间的不一致性。     

基于Viewpoint Agent的新型需求描述模型

需求工程是整个软件工程的关键部分，为了能清晰地得到软件规约，提出了一种新型的需求工程方法——基于多视点的需求代理模型。这个模型结合了多视点方法对分布式环境下的需求描述的能力和Agent的自治能力，从而能在分布式的开发环境下自动地得到软件规约。通过一个实例展示了Viewpoint Agent对基于多视点的需求描述自动进行规约的过程。     

视点合成中重叠需求的不一致优先级处理

对多视点方法来说，各视点不同的利益观可能导致视点之间的重叠需求相对于不同视点优先级设定方面的不一致性．该文主要讨论了视点合成中重叠需求不一致优先级的处理策略和方法．首先作者对需求优先级以及重叠需求相对于不同视点优先级的不一致性等概念给出了严格的定义．其次，对于IEEE推荐标准，作者分别采用格和乘积格来表示重叠需求相对于各视点和合成视点的优先级，借助于乘积格的准布尔特性实现对不一致优先级的容忍策略；最后对基于精确度量设定优先级的情形，采用平均策略确定重叠需求相对于合成视点的综合度量，重新设定重叠需求相对于合成视点的优先级，从而解决这种不一致性．     

关于软件需求中的不一致性管理

复杂软件系统开发的一个关键问题是分析和处理可能存在的不一致的需求描述.这个问题解决得好坏直接影响到需求规格说明的质量,进而影响到最终软件产品的质量.在目前公认的一个不一致需求管理框架的基础上,就需求不一致性管理方面的有代表性的工作,进行了较为系统的分析,以期建立对当前需求工程中,关于不一致的需求管理方法和技术的全面认识.最后,对需求不一致性管理方面的研究进行了展望.     

基于求精关系的多视点需求工程框架模型

1 引论传统需求工程方法应用于大型分布式系统的开发有一个严重问题:需求工程中的每一子过程里只能有一个全局规格。这一点与实际的分布式系统的特点很不适应。大规模的分布式系统的开发必然会涉及到许多人员,这些人员由于各自目的和职责不同,因而都会以自己拥有的知识,从不同的角度、不同的地点、使用不同的语言和工具对系统提出不同的需求;而且,所有的子过程只能串行地进行,降低了系统开发的效率。为了更好地支持分布式系统的需求工程,已经开始出现一些新的需求工程方法,多视点需求工程就是其中之一。多视点需求工程把系统需求划分为多个视点需求。视点既可以是参与者从各自的角度对系统的不同的认识,也可以是按照一定标准对系统的划分;一个视点不仅仅是系统的部分规格,还包括如何求精该部分规格的部分知识。这样,系     

多视点元模型间需求追踪性方法

以全面而统筹的眼光解决问题,则必须从局部分析不同的侧面,面向多视点的需求工程即为该理论的一个应用.多视点需求工程越来越受到重视,但是各视点间却缺少统一,这不仅不利于获取完整的系统需求,还导致需求变更困难等问题.为了解决以上问题,首先提出一个新的多视点建模过程框架,合理的建模框架有利于获取完整的系统需求.其次在多视点建模过程框架下建立追踪元模型,阐明系统需求在多视点元模型间的平稳过渡.最后结合需求追踪矩阵方法在追踪元模型间建立起追踪关系,进而通过计算变化追踪矩阵在需求变更时可以追踪到相关元素并进行更改,解决需求变更困难的问题.     

基于多视点的需求描述模型

本文提出了一个基于多视点的需求描述模型,该模型可通过视点模板来定义用户的需求,此外,本文也结合一个管理信息系统的实例,介绍了使用这一需求描述模型定义软件系统需求的全过程。     

一种基于问题框架的视点表示模型

在多视点需求工程中，视点表示模型与视点需求信息的获取、描述密切相关，影响着后阶段视点一致性的检查和集成。鉴于需求工程领域的发展，该文提出了一种基于问题框架的视点表示模型，展示了该模型的特点及应用。实践表明，该模型具有实用性和可操作性。     

涉众为中心的敏捷需求建模

提出一种将涉众为中心和敏捷方法有机结合的敏捷需求建模方法。所有软件系统需求获取以涉众为中心,基于涉众扩展特征建立涉众Power/Interest分布图来确定涉众优先级,并用优先级处理不同涉众之间的需求冲突,根据涉众为中心的敏捷需求方法,提出敏捷需求实践方法,融合敏捷方法的短周期、演化、增量、迭代、重构、反馈机制,使软件系统需求建模过程更加完备、精确、高效、快捷,用双变迁Petri网DTPN为该方法建立形式化敏捷需求模型,为软件系统需求建模提出了一种新的方法。     

基于信息特征的需求开发与管理研究

如何荻取用户的真正需求是需求工程的难点.需求工程是创造性的高层次知识活动,根据知识等级层次,信息最接近于事实且涉及专业知识最少.以信息方式交流需求具有容易理解的优势,便于减少和消除人们因知识背景不同而产生的交流困难.应用信息特征探讨了几点有效提高需求开发与管理效率的对策.     

GARUSO: a gamification approach for involving stakeholders outside organizational reach in requirements engineering

Stakeholder participation is a key success factor of Requirements Engineering (RE). Typically, the techniques used for identifying and involving stakeholders in RE assume that stakeholders can be identified among the members of the organizations involved when a software system is ordered, developed or maintained—and that these stakeholders can be told or even mandated to contribute. However, these assumptions no longer hold for many of today’s software systems where significant stakeholders (in particular, end-users and people affected by a system) are outside organizational reach: They are neither known nor can they easily be identified in the involved organizations nor can they be told to participate in RE activities. We have developed the GARUSO approach to address this problem. It uses a strategy for identifying stakeholders outside organizational reach and a social media platform that applies gamification for motivating these stakeholders to participate in RE activities. In this article, we describe the GARUSO approach and report on its empirical evaluation. We found that the identification strategy attracted a crowd of stakeholders outside organizational reach to the GARUSO platform and motivated them to participate voluntarily in collaborative RE activities. From our findings, we derived a first set of design principles on how to involve stakeholders outside organizational reach in RE. Our work expands the body of knowledge on crowd RE regarding stakeholders outside organizational reach.

     

An intelligent assistant for requirements validation

The process of determining user requirements for software systems is often plagued with uncertainty, ambiguity, and inconsistency. Rapid prototyping offers an iterative approach to requirements engineering that can be used to alleviate some of the problems with communication and understanding. Since the systems development process is characterized by changing requirements and assumptions, involving multiple stakeholders with often differing viewpoints, it is beneficial to capture the justifications for the decisions in the development process in a structured manner. Thisdesign rationale captured during requirements engineering can be used in conjunction with the rapid prototyping process to support various stakeholders involved in systems development. CAPS (the Computer Aided Prototyping System) has been built to help software engineers rapidly construct prototypes of proposed software systems. REMAP (Representation and MAintenance of Process knowledge) provides a conceptual model and mechanisms to represent and reason with (design) rationale knowledge. In this paper, we describe how in the context of evolving requirements, the CAPS system augmented with REMAP helps firm up software requirements through iterative negotiations via examination of executable prototypes and reasoning with design rationale knowledge.     

基于概念图的多视点需求模型

本文提出了一种以概念图为元表达语言的多视点需求建模方法.该模型提供了一种多视点中不同表示风格带来的问题的解决方法,该方法使用多视点进行需求获取,通过统一建模语言中的协作图简化了视点间的一致性检查,使多视点的集成更为简便.     

Viewpoints: principles, problems and a practical approach to requirements engineering

The paper includes a survey and discussion of viewpoint‐oriented approaches to requirements engineering and a presentation of new work in this area which has been designed with practical application in mind. We describe the benefits of viewpoint‐oriented requirements engineering and describe the strengths and weaknesses of a number of viewpoint‐oriented methods. We discuss the practical problems of introducing viewpoint‐oriented requirements engineering into industrial software engineering practice and why these have prevented the widespread use of existing approaches. We then introduce a new model of viewpoints called Preview. Preview viewpoints are flexible, generic entities which can be used in different ways and in different application domains. We describe the novel characteristics of the Preview viewpoints model and the associated processes of requirements discovery, analysis and negotiation. Finally, we discuss how well this approach addresses some outstanding problems in requirements engineering (RE) and the practical industrial problems of introducing new requirements engineering methods.     

Designing and assessing a course on prioritization and importance assessment in strategic non-routine requirements engineering processes

In this contribution, we present a course for making stakeholders in requirements engineering (RE) processes aware of the relevance of importance assessment (the thinking process that they go through while assessing requirement weights) and giving them some experience with specific aspects of the importance assessment process. We also analyze the experiences of the participants in five pilot sessions. In RE instruments, elicitation of requirement weights receives much attention. However, the processes that individual stakeholders go through while assessing weights are largely ignored or seen as a ‘black box’. In the course, participants gain experience with some common issues and pitfalls in assessing weights. Issues covered are: completeness and interdependence of requirements, causal relationships and the common denominator, handling ‘irrational’ requirements, and the meaning of ‘importance’ (priority). The course was given in various large organizations in the aerospace sector, and data on participants’ experiences were gathered by means of a standardized questionnaire. The extent to which the participants claimed they learned about the relevance of importance assessment and about how to perform it were, respectively, 2.89 and 2.72 on a scale from 1 to 5. The relevance of the various assignments was rated between 3.74 and 4.00 on a 1–5 scale. Our study indicates that the course, or elements of it, should be embedded in an organization’s work practices in order to achieve lasting effects.     

Requirements determination for common systems: turning a global vision into a local reality

A ‘common’ information system is one that is intended to satisfy the needs of multiple user groups within a firm for a particular functionality (e.g. one order entry system to be used by all divisions of a global firm). Such systems are often comprised of both core (or common) software modules, as well as local modules to support regional requirements. One of the most significant challenges for any information systems (IS) project is determining information requirements. The requirements determination process is especially difficult in this context in which common, global requirements must be forged from disparate, and potentially conflicting, local needs and priorities. This paper reports on case studies of two projects undertaken to globally deploy common systems, and it develops a model of the requirements determination process. The proposed model posits stakeholders engage in knowledge acquisition and negotiation processes in order to determine global requirements as well as to foster consensus and buy-in, on the part of the local regional stakeholders, to the global system. The findings also suggest that knowledge acquisition is a relatively structured, rational approach to learning about local needs and requirements, where stakeholders share an awareness of the corporate vision for global standards and agree on the need for a new system. Negotiation, in contrast, is less structured and more political, with different parties lobbying for their own interests as they endeavor to identify common requirements for the new global system. Finally, the results suggest that the requirements determination process is influenced by an articulated corporate vision for a global system, needs and priorities of the local regions, and the organizational roles and skills of key stakeholders. Implications of the results are drawn and suggestions for future research are offered.