Software architecture and mobility: A roadmap

Modern software-intensive systems are characterized not only by the movement of data, as has been the case in traditional distributed systems, but also by the movement of users, devices, and code. Developing effective, efficient, and dependable systems in the mobile setting is challenging. Existing architectural principles need to be adapted and novel architectural paradigms devised. In this paper, we give an overview of the intersection of the areas of software architecture and mobility. We consider mobility from two related perspectives: (1) mobile software, which represents the computing functionality designed to migrate across hardware devices at runtime and execute on mobile hardware platforms, and (2) mobile systems, which are computing applications that include mobile software and hardware elements. We study the advances in both these areas, highlight representative existing solutions, and identify several remaining research challenges.     

A systematic review of software architecture visualization techniques

ContextGiven the increased interest in using visualization techniques (VTs) to help communicate and understand software architecture (SA) of large scale complex systems, several VTs and tools have been reported to represent architectural elements (such as architecture design, architectural patterns, and architectural design decisions). However, there is no attempt to systematically review and classify the VTs and associated tools reported for SA, and how they have been assessed and applied.ObjectiveThis work aimed at systematically reviewing the literature on software architecture visualization to develop a classification of VTs in SA, analyze the level of reported evidence and the use of different VTs for representing SA in different application domains, and identify the gaps for future research in the area.MethodWe used systematic literature review (SLR) method of the evidence-based software engineering (EBSE) for reviewing the literature on VTs for SA. We used both manual and automatic search strategies for searching the relevant papers published between 1 February 1999 and 1 July 2011.ResultsWe selected 53 papers from the initially retrieved 23,056 articles for data extraction, analysis, and synthesis based on pre-defined inclusion and exclusion criteria. The results from the data analysis enabled us to classify the identified VTs into four types based on the usage popularity: graph-based, notation-based, matrix-based, and metaphor-based VTs. The VTs in SA are mostly used for architecture recovery and architectural evolution activities. We have also identified ten purposes of using VTs in SA. Our results also revealed that VTs in SA have been applied to a wide range of application domains, among which “graphics software” and “distributed system” have received the most attention.ConclusionSA visualization has gained significant importance in understanding and evolving software-intensive systems. However, only a few VTs have been employed in industrial practice. This review has enabled us to identify the following areas for further research and improvement: (i) it is necessary to perform more research on applying visualization techniques in architectural analysis, architectural synthesis, architectural implementation, and architecture reuse activities; (ii) it is essential to pay more attention to use more objective evaluation methods (e.g., controlled experiment) for providing more convincing evidence to support the promised benefits of using VTs in SA; (iii) it is important to conduct industrial surveys for investigating how software architecture practitioners actually employ VTs in architecting process and what are the issues that hinder and prevent them from adopting VTs in SA.     

A systematic review of software architecture evolution research

Context

Software evolvability describes a software system’s ability to easily accommodate future changes. It is a fundamental characteristic for making strategic decisions, and increasing economic value of software. For long-lived systems, there is a need to address evolvability explicitly during the entire software lifecycle in order to prolong the productive lifetime of software systems. For this reason, many research studies have been proposed in this area both by researchers and industry practitioners. These studies comprise a spectrum of particular techniques and practices, covering various activities in software lifecycle. However, no systematic review has been conducted previously to provide an extensive overview of software architecture evolvability research.

Objective

In this work, we present such a systematic review of architecting for software evolvability. The objective of this review is to obtain an overview of the existing approaches in analyzing and improving software evolvability at architectural level, and investigate impacts on research and practice.

Method

The identification of the primary studies in this review was based on a pre-defined search strategy and a multi-step selection process.

Results

Based on research topics in these studies, we have identified five main categories of themes: (i) techniques supporting quality consideration during software architecture design, (ii) architectural quality evaluation, (iii) economic valuation, (iv) architectural knowledge management, and (v) modeling techniques. A comprehensive overview of these categories and related studies is presented.

Conclusion

The findings of this review also reveal suggestions for further research and practice, such as (i) it is necessary to establish a theoretical foundation for software evolution research due to the fact that the expertise in this area is still built on the basis of case studies instead of generalized knowledge; (ii) it is necessary to combine appropriate techniques to address the multifaceted perspectives of software evolvability due to the fact that each technique has its specific focus and context for which it is appropriate in the entire software lifecycle.     

软件体系结构初探

介绍了软件体系结构的定义、应用现状、模型、目前的研究状况以及未来发展方向。     

软件体系结构开发方法及其应用

简要介绍了软件体系结构开发方法的作用和内容，对领域专用的软件体系结构的意义和开发方法进行了阐述。通过分析机场领域中信息系统的通用功能需求，提出了系统的拓扑结构，采用统一建模语言建立系统模型，并利用设计模式、中间件、构件等技术实现了领域的软件框架，为领域内系统的实现提供了基础，大大提高了系统的开发效率。     

一种面向软件体系结构的动态重配置方法*

通过在整个软件生命周期建立开发模型,研究了当前软件工程与实际需求之间差异。利用基于XML的中间脚本,提出一种事务处理软件开发模型,实现用户功能需求到表单流、事件流和数据流的转换,动态重配置出不同应用的事务处理软件。建立了企事业信息综合事务处理系统开发平台,分析了平台体系结构和中间脚本,表明可以根据业务变化进行整个系统功能重组而不需要编写一句程序,验证了该模型的可行性和有效性。     

Enriching software architecture documentation

The effective documentation of Architectural Knowledge (AK) is one of the key factors in leveraging the paradigm shift toward sharing and reusing AK. However, current documentation approaches have severe shortcomings in capturing the knowledge of large and complex systems and subsequently facilitating its usage. In this paper, we propose to tackle this problem through the enrichment of traditional architectural documentation with formal AK. We have developed an approach consisting of a method and an accompanying tool suite to support this enrichment. We evaluate our approach through a quasi-controlled experiment with the architecture of a real, large, and complex system. We provide empirical evidence that our approach helps to partially solve the problem and indicate further directions in managing documented AK.     

基于设计模式的星载软件体系结构设计方法

星载软件是整个卫星系统设计和开发的中心,而体系结构是整个软件开发的蓝图,在软件开发中占有十分重要的位置。为了提高星载软件开发效率,降低研制成本,同时满足实时性、可重构和可维护性要求,从体系结构的前3个视图方面采用基于设计模式的方法提出了一种满足要求的星载软件体系结构。     

基于政策自组织系统的软件agent体系结构及其实现

当前自组织系统软件工程面临的一个重要挑战,就是如何设计适宜的个体交互行为来满足自组织系统的宏观涌现需求。针对此问题,提出了一种基于政策的自组织多agent系统的开发方法,此方法通过政策调节引导agent的行为,以期在系统层面得到用户所需求的宏观涌现结果。开发这类系统的核心问题是如何构造系统中的软件agent,使得agent能够感知、理解系统政策,并在遵循政策的前提下实现行为的自主决策。提出了一种基于政策自组织多agent系统的软件agent体系结构,并基于该体系结构设计了运行机制及行为决策算法。通过软件方式实现了一个基于政策的自组织多agent系统开发平台原型,并通过案例实现说明了体系结构、运行机制的有效性。     

Controlling software architecture erosion: A survey

Software architectures capture the most significant properties and design constraints of software systems. Thus, modifications to a system that violate its architectural principles can degrade system performance and shorten its useful lifetime. As the potential frequency and scale of software adaptations increase to meet rapidly changing requirements and business conditions, controlling such architecture erosion becomes an important concern for software architects and developers. This paper presents a survey of techniques and technologies that have been proposed over the years either to prevent architecture erosion or to detect and restore architectures that have been eroded. These approaches, which include tools, techniques and processes, are primarily classified into three generic categories that attempt to minimise, prevent and repair architecture erosion. Within these broad categories, each approach is further broken down reflecting the high-level strategies adopted to tackle erosion. These are: process-oriented architecture conformance, architecture evolution management, architecture design enforcement, architecture to implementation linkage, self-adaptation and architecture restoration techniques consisting of recovery, discovery and reconciliation. Some of these strategies contain sub-categories under which survey results are presented.We discuss the merits and weaknesses of each strategy and argue that no single strategy can address the problem of erosion. Further, we explore the possibility of combining strategies and present a case for further work in developing a holistic framework for controlling architecture erosion.     

Comparative case studies of open source software peer review practices

ContextThe power of open source software peer review lies in the involvement of virtual communities, especially users who typically do not have a formal role in the development process. As communities grow to a certain extent, how to organize and support the peer review process becomes increasingly challenging. A universal solution is likely to fail for communities with varying characteristics.ObjectiveThis paper investigates differences of peer review practices across different open source software communities, especially the ones engage distinct types of users, in order to offer contextualized guidance for developing open source software projects.MethodComparative case studies were conducted in two well-established large open source communities, Mozilla and Python, which engage extremely different types of users. Bug reports from their bug tracking systems were examined primarily, complemented by secondary sources such as meeting notes, blog posts, messages from mailing lists, and online documentations.ResultsThe two communities differ in the key activities of peer review processes, including different characteristics with respect to bug reporting, design decision making, to patch development and review. Their variances also involve the designs of supporting technology. The results highlight the emerging role of triagers, who bridge the core and peripheral contributors and facilitate the peer review process. The two communities demonstrate alternative designs of open source software peer review and their tradeoffs were discussed.ConclusionIt is concluded that contextualized designs of social and technological solutions to open source software peer review practices are important. The two cases can serve as learning resources for open source software projects, or other types of large software projects in general, to cope with challenges of leveraging enormous contributions and coordinating core developers. It is also important to improve support for triagers, who have not received much research effort yet.     

Composing enterprise mashup components and services using architecture integration patterns

Enterprise mashups leverage various source of information to compose new situational applications. The architecture of such applications must address integration issues: it needs to deal with heterogeneous local and/or public data sources, and build value-added applications on existing corporate IT systems. In this paper, we leverage enterprise architecture integration patterns to compose reusable mashup components. We present a service oriented architecture that addresses reusability and integration needs for building enterprise mashup applications. Key techniques to customize this architecture are developed for mashups with themed data on location maps. The usage of this architecture is illustrated by a property valuation application derived from a real-world scenario. We demonstrate and discuss how this state-of-the-art architecture design method can be applied to enhance the design and development of emerging enterprise mashups.     

一个领域软件集成框架的研究与实现

文章论述了领域开放软件集成框架的设计思想、目标和标准体系,研究了实现领域软件数据共享,即插即用和 构筑虚拟应用的技术思路,给出了一个石油软件集成框架系统,介绍了它的功能、体系结构和核心模块的实现。     

软件体系结构建模研究

提出了软件体系结构工程的概念，建立了软件体系结构的生命周期模型并对软件体系结构进行了分类和建模，介绍了几种典型的软件体系结构语言，提出了一个基于时序逻辑的形式化体系结构语言－ＸＹＺ／ＳＡＥ．该语言可作为系列化时序逻辑语言族ＸＹＺ／Ｅ的子语言，支持对软件体系结构可的构件，连接件和配置的描述，并可在统一的框架下描述软件体系的结构静态行为和动态行为。     

Software architecture awareness in long-term software product evolution

Software architecture has been established in software engineering for almost 40 years. When developing and evolving software products, architecture is expected to be even more relevant compared to contract development. However, the research results seem not to have influenced the development practice around software products very much. The architecture often only exists implicitly in discussions that accompany the development. Nonetheless many of the software products have been used for over 10, or even 20 years. How do development teams manage to accommodate changing needs and at the same time maintain the quality of the product? In order to answer this question, grounded theory study based on 15 semi-structured interviews was conducted in order to find out about the wide spectrum of architecture practices in software product developing organisations. Our results indicate that a chief architect or central developer acts as a ‘walking architecture’ devising changes and discussing local designs while at the same time updating his own knowledge about problematic aspects that need to be addressed. Architecture documentation and representations might not be used, especially if they replace the feedback from on-going developments into the ‘architecturing’ practices. Referring to results from Computer Supported Cooperative Work, we discuss how explicating the existing architecture needs to be complemented by social protocols to support the communication and knowledge sharing processes of the ‘walking architecture’.     

Software process modeling languages: A systematic literature review

ContextOrganizations working in software development are aware that processes are very important assets as well as they are very conscious of the need to deploy well-defined processes with the goal of improving software product development and, particularly, quality. Software process modeling languages are an important support for describing and managing software processes in software-intensive organizations.ObjectiveThis paper seeks to identify what software process modeling languages have been defined in last decade, the relationships and dependencies among them and, starting from the current state, to define directions for future research.MethodA systematic literature review was developed. 1929 papers were retrieved by a manual search in 9 databases and 46 primary studies were finally included.ResultsSince 2000 more than 40 languages have been first reported, each of which with a concrete purpose. We show that different base technologies have been used to define software process modeling languages. We provide a scheme where each language is registered together with the year it was created, the base technology used to define it and whether it is considered a starting point for later languages. This scheme is used to illustrate the trend in software process modeling languages. Finally, we present directions for future research.ConclusionThis review presents the different software process modeling languages that have been developed in the last ten years, showing the relevant fact that model-based SPMLs (Software Process Modeling Languages) are being considered as a current trend. Each one of these languages has been designed with a particular motivation, to solve problems which had been detected. However, there are still several problems to face, which have become evident in this review. This let us provide researchers with some guidelines for future research on this topic.     

面向软件演化的可靠性分析代数方法

环境和需求的改变导致软件演化发生,并通常会使软件架构(Software architecture,SA)产生变化.现有的结构化软件可靠性模型对评价软件初始结构设计有不错的效果,但在软件演化时的实时分析方面有局限性.从软件结构建模出发,通过使用代数方法将软件演化描述为原子操作序列,并跟踪分析序列中每一步操作对可靠性的影响...     

Bridging the gap between software architecture rationale formalisms and actual architecture documents: An ontology-driven approach

Documenting software architecture rationale is essential to reuse and evaluate architectures, and several modeling and documentation guidelines have been proposed in the literature. However, in practice creating and updating these documents rarely is a primary activity in most software projects, and rationale remains hidden in casual and semi-structured records, such as e-mails, meeting notes, wikis, and specialized documents. This paper describes the TREx (Toeska Rationale Extraction) approach to recover, represent and explore rationale information from text documents, combining: (1) pattern-based information extraction to recover rationale; (2) ontology-based representation of rationale and architectural concepts; and (3) facet-based interactive exploration of rationale. Initial results from TREx’s application suggest that some kinds of architecture rationale can be semi-automatically extracted from a project’s unstructured text documents, namely decisions, alternatives and requirements. The approach and some tools are illustrated with a case study of rationale recovery for a financial securities settlement system.