从面向对象到面向目标的需求分析

一、前言软件系统的成功极大地依赖软件需求分析的质量。有人做过统计,在美国和西欧国家,软件项目失败的两个最主要的原因:一是缺乏用户参与和不完整的需求,二是低质量的需求规格说明书。如果能找到一些方法和技术能精确描述用户的需求,(自动地)生成完整、一致、可修改性好、可跟踪性强的软件需求规格     

面向SAAS模式的日志架构设计与实现

日志在软件系统的开发和运行阶段起着非常重要的作用。根据SaaS(Software as a Service)软件单系统多租赁这种一对多的服务模式提出一个能够与SaaS软件集成的日志架构Log4SaaS(Log For SaaS)。通过对该日志架构进行相应的配置和扩展,能够满足SaaS软件分别针对不同用户记录日志的要求。从总体上描述架构的框架设计,并对该架构所有的关键技术进行了分析和讨论,预见了日志架构未来的发展潜力。     

The measurement of software design quality

Software quality involves the conformance of a software product to some predefined set of functional requirements at a specified level of quality. The software is considered valid when it conforms to these “quality factors” at some acceptable level. There are a large number of quality factors against which software may be validated. This paper discusses the development of traditional software metrics in relation to the anticipated structure of a software system. The taxonomy of a software system primarily relies upon the dissection of the software system into modules. Modular design is the cornerstone of quality software, and metrics that can predict an optimum modular structure are critical. By examining the theoretical bases on quality metrics, a base set of common quantitative metrics can be devised and mapped to quality metrics in which they reside. This paper surveys existing metrics and suggests the derivation of software design metrics from software quality factors. Measurable software attributes are identified and suggested as potential design metrics.     

一种软件设计决策的优选方法

在软件维护和演化的工业实践中,软件设计者往往依赖主观经验或直觉对软件的设计进行修改来应对变化的需求。但这导致了决策随意性和不可重现性。结合质量属性的度量将软件设计决策进行量化,从而显式地表示、记录这些经验和直觉。并通过记录所有备选的修改,用于指导将来的软件演化。给出一个基于质量属性度量和决策历史的设计决策优选方法框架,结合一个工业应用的实例进行分析,并讨论了实际应用的效果和可能的改进。     

基于软件总线的小卫星系统软件可重用结构设计

提出了一种小型探测卫星系统软件的可重用性结构设计方法。为实现可重用性,软件结构采用了模块化策略,各任务模块间相互通信采用了“软件总线”概念。软件总线为每个任务模块提供一个简单的标准化数据通信接口,因此对某一星载系统任务模块的修改或增加或替换时不影响其它任务模块,同时某些场合,卖命通过对地面上实时地改变软件总线上的调度表内容的方法,很容易改变卫星的工作状态。在星载系统软件软件开发周期内,各任务模块通     

Software diversity: state of the art and perspectives

Diversity is prevalent in modern software systems to facilitate adapting the software to customer requirements or the execution environment. Diversity has an impact on all phases of the software development process. Appropriate means and organizational structures are required to deal with the additional complexity introduced by software variability. This introductory article to the special section “Software Diversity—Modeling, Analysis and Evolution” provides an overview of the current state of the art in diverse systems development and discusses challenges and potential solutions. The article covers requirements analysis, design, implementation, verification and validation, maintenance and evolution as well as organizational aspects. It also provides an overview of the articles which are part of this special section and addresses particular issues of diverse systems development.     

Design rationale capture for process improvement in the globalised enterprise: an industrial study

Design rationale fills in the gaps between the original requirements of a system and the finished product encompassing decisions, constraints and other information that influenced the outcome. Existing research in Software Engineering corroborates the importance of design rationale to capture knowledge assets, particularly in the context of the global enterprise, with its increased reliance on IT systems, and risk of knowledge loss through staff movement and attrition. Despite this, the practice of design rationale capture is not as extensive as could be expected due to reasons which include time and budget constraints, the lack of standards and tools, and some uncertainty as to its actual added value. In this paper, we address the viability and benefits of capturing design rationale as a by-product of design in the context of a real-world global organisational setting. This was achieved through a study in which an emerging design approach—Problem Oriented Engineering—was applied in the context of a global financial institution to address a critical IT problem as part of its software supplier’s client resolution process. The study provides some positive evidence that the approach-guided knowledge capture of key design rationale elements and that it combined well with existing practices within the organisation and even led to improvement to one of their key processes.     

From safety analysis to software requirements

Software for safety critical systems must deal with the hazards identified by safety analysis. This paper investigates, how the results of one safety analysis technique, fault trees, are interpreted as software safety requirements to be used in the program design process. We propose that fault tree analysis and program development use the same system model. This model is formalized in a real-time, interval logic, based on a conventional dynamic systems model with state evolving over time. Fault trees are interpreted as temporal formulas, and it is shown how such formulas can be used for deriving safety requirements for software components     

An empirical study of object-oriented system evolution

Software metrics have been used to measure software artifacts statically—measurements are taken after the artifacts are created. In this study, three metrics—System Design Instability (SDI), Class Implementation Instability (CII), and System Implementation Instability (SII)—are used for the purpose of measuring object-oriented (OO) software evolution. The metrics are used to track the evolution of an OO system in an empirical study. We found that once an OO project starts, the metrics can give good indications of project progress, e.g. how mature the design and implementation is. This information can be used to adjust the project plan in real time.We also performed a study of design instability that examines how the implementation of a class can affect its design. This study determines that some aspects of OO design are independent of implementation, while other aspects are dependent on implementation.     

Facilitating software extension with design patterns and Aspect-Oriented Programming

Software products, especially large applications, need to continuously evolve, in order to adapt to the changing environment and updated requirements. With both the producer and the customer unwilling to replace the existing application with a completely new one, adoption of design constructs and techniques which facilitate the application extension is a major design issue. In the current work we investigate the behavior of an object-oriented software application at a specific extension scenario, following three implementation alternatives with regards to a certain design problem relevant to the extension. The first alternative follows a simplistic solution, the second makes use of a design pattern and the third applies Aspect-Oriented Programming techniques to implement the same pattern. An assessment of the three alternatives is attempted, both on a qualitative and a quantitative level, by identifying the additional design implications needed to perform the extension and evaluating the effect of the extension on several quality attributes of the application.     

An interactive graphics system for 2-D drawing and design

This paper is about a software system, GRASS-Graphic Software System for 2-D drawing and design—which has been implemented on a $\text{PDP}\text{-}\text{11}\text{35}$ system with RSX-11M operating system. It is a low cost interactive graphics system for the design of two dimensional drawings and uses a minimum of hardware. It provides comprehensive facilities for creating, editing, storing and retrieving pictures. It has been implemented in the language Pascal and has the potential to be used as a powerful data-imputting tool for a design-automation system. The important features of the system are its low cost, software character generation and a user-trainable character recognizer, which has been included.     

计算机软件的可靠性设计研究

软件可靠性随着科学技术的逐渐进步已成为我们需要关注的一个问题,软件系统的可靠性随着其规模的加大就会变得越发难以保证。应用本身对系统运行可靠性的要求逐渐增高,尤其是在如航天、航空等一些关键的应用领域,对其可靠性的要求就更加重要,软件系统的可靠性在银行等服务性行业中也和其自身的生存发展竞争能力和声誉有着直接的关系。本文对软件可靠性设计的基本概念进行了介绍,并且对软件可靠性设计方法着重进行了介绍。     

一种基于场景的软件维护性需求分析方法

软件维护性是软件质量的重要属性之一,它在很大程度上决定了软件的后期维护成本。设计赋予软件良好的维护性是软件需求、设计和开发经常忽视的一个问题,也是一个难题。提出了一种基于场景的软件维护性需求分析方法,即通过对软件将来可能发生的维护场景进行分析以获取软件可维护性需求。     

自动售货机金钱管理系统中 AOP 框架设计与应用

针对传统自动售货机软件体系结构中软件各组件间关系复杂、组件职责不清晰等问题基础上,转向AOP技术,提出了一种面向自动售货机实时系统软件开发领域的可复用、分层的面向方面软件实现框架R-AoSAS,该架构使得功能组件模块和非功能组件模块分离,为了实现功能组件和非功能组件的绑定或组合,该框架通过调用方面的Join Point作为它们之间的接口。在应用该框架进行实时系统软件开发时,对于定时服务、任务创建和任务调度等非功能约束的实现可以交给R-AoSAS框架核心控制层提供的时间管理模型和任务调度模型去完成,从而在软件产品层面上提高系统软件开发的质量和软件的复用性。为了验证R-AoSAS的性能,将该框架应用于金钱管理系统的开发设计,从该系统的应用中充分体现了该框架的应用前景。     

A new approach in development of distributed framework for automated software testing using agents

Software testing is the technical kernel of software quality engineering, and to develop critical and complex software systems not only requires a complete, consistent and unambiguous design, and implementation methods, but also a suitable testing environment that meets certain requirements, particularly, to face the complexity issues. Traditional methods, such as analyzing each requirement and developing test cases to verify correct implementation, are not effective in understanding the software’s overall complex behavior. In that respect, existing approaches to software testing are viewed as time-consuming and insufficient for the dynamism of the modern business environment. This dynamics requires new tools and techniques, which can be employed in tandem with innovative approaches to using and combining existing software engineering methods. This work advocates the use of a recently proposed software engineering paradigm, which is particularly suited to the construction of complex and distributed software-testing systems, which is known as Agent-Oriented Software Engineering. This methodology is a new one, which gives the basic approach to agent-based frameworks for testing.     

基于构件的软件复用在商品订单管理系统中的应用

软件体系结构设计是近几年来流行的软件设计模式,而基于构件的软件复用技术也逐步应用到整个系统的开发过程中。文章简单阐述了软件复用的基本概念及构件在软件复用中的重要地位,并利用软件复用技术设计开发了一个基于J2EE架构的商品订单管理系统。重点介绍了系统的总体设计思想和模块组成,体现了软件复用在系统设计和快速实现时所具有的突出优势和强大的生命力。     

A Framework for Design Tradeoffs

Designs almost always require tradeoffs between competing design choices to meet system requirements. We present a framework for evaluating design choices with respect to meeting competing requirements. Specifically, we develop a model to estimate the performance of a UML design subject to changing levels of security and fault-tolerance. This analysis gives us a way to identify design solutions that are infeasible. Multi-criteria decision making techniques are applied to evaluate the remaining feasible alternatives. The method is illustrated with two examples: a small sensor network and a system for controlling traffic lights. Dr. Anneliese Amschler Andrews is Professor and Chair of the Department of Computer Science at the University of Denver. Before that she was the Huie Rogers Endowed Chair in Software Engineering at Washington State University. Dr. Andrews is the author of a text book and over 130 articles in the area of Software Engineering, particularly software testing and maintenance. Dr. Andrews holds an MS and PhD from Duke University and a Dipl.-Inf. from the Technical University of Karlsruhe. She served as Editor-in-Chief of the IEEE Transactions on Software Engineering. She has also served on several other editorial boards including the IEEE Transactions on Reliability, the Empirical Software Engineering Journal, the Software Quality Journal, the Journal of Information Science and Technology, and the Journal of Software Maintenance. She was Director of the Colorado Advanced Software Institute from 1995 to 2002. CASI's mission was to support technology transfer research related to software through collaborations between industry and academia. Ed Mancebo studied software engineering at Milwaukee School of Engineering and computer science at Washington State University. His masters thesis explored applying systematic decision making methods to software engineering problems. He is currently a software developer at Amazon.com. Dr. Per Runeson is a professor in software engineering at Lund University, Sweden. His research interests include methods to facilitate, measure and manage aspects of software quality. He received a PhD from Lund University in 1998 and has industrial experience as a consulting expert. He is a member of the editorial board of Empirical Software Engineering and several program committees, and currently has a senior researcher position funded by the Swedish Research Council. Robert France is currently a Full Professor in the Department of Computer Science at Colorado State University. His research interests are in the area of Software Engineering, in particular formal specification techniques, software modeling techniques, design patterns, and domain-specific modeling languages. He is an Editor-in-Chief of the Springer journal on Software and System Modeling (SoSyM), and is a Steering Committee member and past Steering Committee Chair of the MoDELS/UML conference series. He was also a member of the revision task forces for the UML 1.x standards.     

Software health management: a necessity for safety critical systems

As software and software intensive systems are becoming increasingly ubiquitous, the impact of failures can be tremendous. In some industries such as aerospace, medical devices, or automotive, such failures can cost lives or endanger mission success. Software faults can arise due to the interaction between the software, the hardware, and the operating environment. Unanticipated environmental changes lead to software anomalies that may have significant impact on the overall success of the mission. Latent coding errors can at any time during system operation trigger faults despite the fact that usually a significant effort has been expended in verification and validation (V&V) of the software system. Nevertheless, it is becoming increasingly more apparent that pre-deployment V&V is not enough to guarantee that a complex software system meets all safety, security, and reliability requirements. Software Health Management (SWHM) is a new field that is concerned with the development of tools and technologies to enable automated detection, diagnosis, prediction, and mitigation of adverse events due to software anomalies, while the system is in operation. The prognostic capability of the SWHM to detect and diagnose failures before they happen will yield safer and more dependable systems for the future. This paper addresses the motivation, needs, and requirements of software health management as a new discipline and motivates the need for SWHM in safety critical applications.