The impact of global dispersion on coordination,team performance and software quality – A systematic literature review

ContextGlobal software development (GSD) contains different context setting dimensions, which are essential for effective teamwork and success of projects. Although considerable research effort has been made in this area, as yet, no agreement has been reached about the impact of these dispersion dimensions on team coordination and project outcomes.ObjectiveThis paper summarizes empirical evidence on the impact of global dispersion dimensions on coordination, team performance and project outcomes.MethodWe performed a systematic literature review of 46 publications from 25 journals and 19 conference and workshop proceedings, which were published between 2001 and 2013. Thematic analysis was used to identify global dimensions and their measures. Vote counting was used to decide on the impact trends of dispersion dimensions on team performance and software quality.ResultsGlobal dispersion dimensions are consistently conceptualized, but quantified in many different ways. Different dispersion dimensions are associated with a distinct set of coordination challenges. Overall, geographical dispersion tends to have a negative impact on team performance and software quality. Temporal dispersion tends to have a negative impact on software quality, but its impact on team performance is inconsistent and can be explained by type of performance.ConclusionFor researchers, we reveal several opportunities for future research, such as coordination challenges in inter-organizational software projects, impact of processes and practices mismatches on project outcomes, evolution of coordination needs and mechanism over time and impact of dispersion dimensions on open source project outcomes. For practitioners, they should consider the tradeoff between cost and benefits while dispersing tasks, alignment impact of dispersion dimensions with individual and organizational objectives, coordination mechanisms as situational approaches and collocation of development activities of high quality demand components in GSD projects.     

Categorization of risk factors for distributed agile projects

ContextOrganizations combine agile approach and Distributed Software Development (DSD) in order to develop better quality software solutions in lesser time and cost. It helps to reap the benefits of both agile and distributed development but pose significant challenges and risks. Relatively scanty evidence of research on the risks prevailing in distributed agile development (DAD) has motivated this study.ObjectiveThis paper aims at creating a comprehensive set of risk factors that affect the performance of distributed agile development projects and identifies the risk management methods which are frequently used in practice for controlling those risks.MethodThe study is an exploration of practitioners’ experience using constant comparison method for analyzing in-depth interviews of thirteen practitioners and work documents of twenty-eight projects from thirteen different information technology (IT) organizations. The field experience was supported by extensive research literature on risk management in traditional, agile and distributed development.ResultsAnalysis of qualitative data from interviews and project work documents resulted into categorization of forty-five DAD risk factors grouped under five core risk categories. The risk categories were mapped to Leavitt’s model of organizational change for facilitating the implementation of results in real world. The risk factors could be attributed to the conflicting properties of DSD and agile development. Besides that, some new risk factors have been experienced by practitioners and need further exploration as their understanding will help the practitioners to act on time.ConclusionOrganizations are adopting DAD for developing solutions that caters to the changing business needs, while utilizing the global talent. Conflicting properties of DSD and agile approach pose several risks for DAD. This study gives a comprehensive categorization of the risks faced by the practitioners in managing DAD projects and presents frequently used methods to reduce their impact. The work fills the yawning research void in this field.     

Exploring principles of user-centered agile software development: A literature review

ContextIn the last decade, software development has been characterized by two major approaches: agile software development, which aims to achieve increased velocity and flexibility during the development process, and user-centered design, which places the goals and needs of the system’s end-users at the center of software development in order to deliver software with appropriate usability. Hybrid development models, referred to as user-centered agile software development (UCASD) in this article, propose to combine the merits of both approaches in order to design software that is both useful and usable.ObjectiveThis paper aims to capture the current state of the art in UCASD approaches and to derive generic principles from these approaches. More specifically, we investigate the following research question: Which principles constitute a user-centered agile software development approach?MethodWe conduct a systematic review of the literature on UCASD. Identified works are analyzed using a coding scheme that differentiates four levels of UCASD: the process, practices, people/social and technology dimensions. Through subsequent synthesis, we derive generic principles of UCASD.ResultsWe identified and analyzed 83 relevant publications. The analysis resulted in a comprehensive coding system and five principles for UCASD: (1) separate product discovery and product creation, (2) iterative and incremental design and development, (3) parallel interwoven creation tracks, (4) continuous stakeholder involvement, and (5) artifact-mediated communication.ConclusionOur paper contributes to the software development body of knowledge by (1) providing a broad overview of existing works in the area of UCASD, (2) deriving an analysis framework (in form a coding system) for works in this area, going beyond former classifications, and (3) identifying generic principles of UCASD and associating them with specific practices and processes.     

基于体系结构的软件可靠性评估综述

为深入了解基于体系结构的软件可靠性评估方法的发展情况,针对当前该方法的发展现状,对基于体系结构的软件可靠性评估的起源、发展、分类和典型模型进行阐述,重点介绍状态模型、路径模型、构建操作剖面模型及其它模型;根据各种模型的特点,分析现有模型中存在的问题,对软件可靠性模型今后的发展趋势进行展望。     

多步历史估计信息反馈多模型融合方法

针对强机动和大观测误差下的目标跟踪问题,传统低阶多模型融合方法存在估计精度较低、鲁棒性较差的缺点;高阶多模型融合方法面临计算量增大和保证实时性之间的矛盾.为此本文针对一类多步稳健机动目标跟踪问题提出一种基于历史估计信息反馈的多模型融合框架,首先累积和反馈历史估计信息,然后结合当前量测计算多阶模型序列的似然函数,最后得到贝叶斯后验融合结果.同时结合粒子滤波构建了易于工程实现的粒子滤波历史反馈多模型融合算法(PF-HFMM).仿真表明,与传统粒子滤波多模型算法相比,本法显著提高了估计精度和鲁棒性.     

开源软件社区开发者偏好合作行为研究

着重从开发者角度出发,先对SourceForge.net开源社区项目与开发者数量增长情况进行统计分析,以见证社区的快速发展;随后以两个月为时间段分析新增开发者、合作的数目,并将开发者之间新建的合作细分为4种情况,探析4种合作方式情况下的差异,进而判断社区开发者优先选择合作方式的顺序;最后针对新开发者与社区已有开发者之间的合作,分析了新开发者的合作偏好与已有开发者的度数中心性、介数中心性和接近中心性,以及他们的开发项目数与之前项目中角色的关系,发现新成员优先选择与介数中心性或度数中心性大的已有开发者合作,且这些开发者整体上都具有多次开发经验并在开发过程中担任过特定角色。研究结果有利于优化群体软件开发过程,为提高群体软件开发效率与质量水平奠定了基础。     

仿鱼长鳍波动推进水下航行器研究进展与分析

作为一种新型水下机器人,仿鱼长鳍波动推进水下航行器具有噪声低、机动性好等传统水下航行器无法比拟的优点,并得到相关研究人员的广泛关注。本文主要介绍了国内外在仿鱼长鳍波动推进水下航行器推进机理和系统研制方面开展的主要研究工作,在此基础上,分析总结了提升仿鱼长鳍波动推进水下航行器性能需要深入讨论和研究的一些问题。     

城市智能交通系统技术发展现状及趋势

城市化的快速发展带来一系列的交通问题,智能交通系统(Intelligent Transportation Systems,ITS)是解决交通问题的有效途径之一。本文主要介绍了智能交通系统的概念与内涵、我国城市智能交通系统技术发展与智能交通管控系统应用现状,在上述内容的基础上,总结了我国城市智能交通系统未来的发展趋势。     

基于L-系统的分形植物形态建模方法研究

植物生长过程中所表现出来的分形特征是虚拟植物形态发生的重要研究内容,而L-系统在表达具有分形特征的虚拟植物形态上具有明显的不可控特点,严重影响了L-系统的广泛应用。为了更好地研究自然界植物的分形特征,以植物分枝结构和几何形态的量化为前提,建立植物分形特征和L-系统的映射关系,应用改进的L-系统拟合分形植物的生长过程,并结合B-样条曲线动态控制分形植物的弯曲,生成丰富多样的、具有逼真分形效果的虚拟植物形态。