This paper presents a technique developed at the Software Engineering Institute (SEI) for encapsulating quality attribute knowledge for use in the design and validation of software architectures. A reasoning framework, our encapsulation mechanism, can be used by nonexperts to analyze a specific quality (e.g., performance, modifiability, availability) of a system.

This report gives an overview of the 6th ICSE Workshop on Component-Based Software Engineering held at 25th International Conference on Software Engineering. The workshop brought together researchers and practitioners from three communities: component technology, software architecture, and software certification. The primary goal of the workshop was to continue clarifying the concepts, identifying the main challenges and findings of predictable assembly of certifiable software components. This report gives a comprehensive summary of the position papers, of the workshop, its findings, and its results.

This workshop brings together researchers and practitioners from the community interested in predictable assembly from certifiable components. The goal of this workshop is to ensure continued collaboration among the members of this community. One output of the workshop will be an understanding of composition theory and how it applies to community model problems that were suggested at the workshop on component-based software engineering held at ICSE in 2001. A second output will be the identification of research opportunities that lie on the perimeter of predictable assembly.

The question of which design methods are appropriate for component-based development (CBD) is complicated by different understandings of the end objectives CBD. A further complication is different understandings of what is meant by "component." These differences lead to entirely distinct classes of design problem. The aim of this tutorial is to, first, outline the differing interpretations of CBD, and, second, to outline the required methodological responses to these design problems.

Information systems are critical assets for modern enterprises and incorporate key knowledge acquired over the life of an organization. These systems must be updated continuously to reflect evolving business practices. Unfortunately, repeated modification has a cumulative effect on system complexity, and the rapid evolution of technology quickly renders existing technologies obsolete. Eventually, the existing information systems become too fragile to modify and too important to discard. For this reason, organizations must consider modernizing these legacy systems to remain viable. The commercial market provides a variety of solutions to this increasingly common problem of legacy system modernization. Understanding the strengths and weaknesses of each modernization technique is paramount to select the correct solution and the overall success of a modernization effort. This paper provides a survey of modernization techniques, including screen scraping, database gateways, XML integration, CGI integration, object-oriented wrapping and "componentization" of legacy systems. This general overview enables engineers performing legacy system modernization to pre-select a subset of applicable modernization techniques for further evaluation.

Members of the COTS-based system initiative at the Software Engineering Institute have developed the Generic Enterprise Ensemble (GEE), a generic approach to building distributed, transaction based, secure enterprise information systems (EIS). GEE is a tool to help in the selection of technologies and architectural choices when building enterprise information systems. Enterprise JavaBeans/sup TM/ (EJB) is a specification from Sun Microsystems for an application server based on Java technology. a comparison is made between GEE based solutions and off-the-shelf solutions based on the EJB specification.

No abstract available.

The Object Management Group's (OMG) Common Object Request Broker Architecture (CORBA) is an important and popular technology that supports the development of object based, distributed applications. The benefits promised by CORBA (abstraction, heterogeneity, etc.) are appealing in many application domains, including those that satisfy real time requirements-such as manufacturing. Unfortunately, CORBA was not specified in light of real time requirements, and so the question remains whether existing object request brokers (ORBs) can be used in real time settings, or whether developers of real time systems must await future extensions of CORBA that address real time issues or use non CORBA compliant ORBs. We describe the application of an off the shelf ORB in a real time manufacturing system developed at National institute of Standards and Technology (NIST) and tools which have been developed at the SEI for the analysis of CORBA's impact on the behavior of the system. Based on our experiences, we believe that today's ORBs can be used in real time settings, with certain caveats as outlined in the article. We also outline the concept of "composite objects", an approach for extending the range of non real time ORBs into a greater variety of real time settings.

An increasingly commonplace reengineering problem involves the integration of legacy software components into new and often novel configurations. These scenarios are arising more frequently, in large measure because of the success of network computing concepts, and in particular the success of web-based Intranets. The author considers the problem of coordination mismatch in legacy components. He discusses their classification and repair, and considers the use of distributed object technology

Many organizations are moving toward greater use of commercial off-the-shelf (COTS) components in the development of application systems. The development of component based systems introduces fundamental changes in the way systems are acquired, integrated, deployed and evolved. We present a reference model for the assembly of component based systems that can be used as the basis for defining a systematic approach to the development of such systems. This reference model is described, and used to explore a number of fundamental development issues.

Many organizations face a serious challenge introducing new technologies into existing systems. Effective modernization requires knowing and articulating specific goals for the reengineering effort, conscious selection of technologies and technical approaches that can achieve those goals in the context of the class of system being upgraded, a staged migration plan, and an integration strategy to make in-hand components work under the newly adopted architecture. Although the study of reengineering is moving towards an engineering discipline, there are as yet no proven decision frameworks that allow an organization to rationally choose a modernization strategy. This paper provides an in-depth look at the engineering trade-offs made in modernizing a manufacturing engineering design system to use distributed object technology. From this case study, the outlines of a more general reengineering decision framework can be seen, and these are discussed.

It has been difficult to objectively assess the real value or maturity of the Object Management Group's Object Management Architecture (OMA). While experience reports have appeared in the literature, these have focused more on the functionality of the end-system than on systematically exploring the strengths and weaknesses of the OMA, and providing practical guidelines on the effective use of the OMA for specific software-engineering problems. In this paper we describe a case study in the use of the OMA to integrate legacy software components into a distributed object system. We assess the OMA in this problem context, and indicate strengths and weaknesses of the specification and current implementations. We extrapolate our experience to a broader class of component-based software systems, and recommend an architectural strategy for the effective use of the OMA to this class of systems.