2nd International Conference on Trends in Enterprise Application Architecture
Developing Realistic Approaches for the Migration of Legacy Components to Service-Oriented Architectures
Tutorial by Grace Lewis and Dennis Smith, SEI, USA
This 3 hour tutorial addresses the problem of the migration of legacy assets to a Service-Oriented Architecture (SOA). It addresses how to develop a realistic strategy for performing such a migration, taking into account both the needs of the organization and the technical content of the organization’s existing systems portfolio.
The tutorial outlines an approach for performing an overall analysis and making decisions on the types of legacy assets that are candidates for migration. It highlights the challenges of building an SOA and presents the issues of SOA-based system development from three perspectives: the application developer, the infrastructure developer, and the service provider. The needs and concerns of each of these participants are considered in order to develop successful systems based on SOAs.
Because there is a current trend of organizations that are leveraging the value of their legacy systems by exposing all or parts of it as services within an SOA, the concerns and needs of the service provider will be presented in greater detail. SMART, a method for making decisions on the migration of legacy assets as services within an SOA, that considers all three perspectives, will be presented. A case study using the method will provide a real world context for its applicability. Open issues and current research topics will be outlined.
This tutorial is targeted to practitioners who are planning to migrate to service-oriented architectures or are currently involved in a migration effort. The shorter the duration of the tutorial, the more familiarity with SOAs is expected of the attendees.
Service-oriented architectures (SOAs) have become an increasingly popular mechanism for achieving interoperability between legacy systems. Because they have characteristics of loose coupling, published interfaces, and a standard communication model, SOAs enable existing legacy systems to expose their functionality as services, presumably without making significant changes to the legacy systems. Case studies are beginning to show that this promise is achievable. Migration to services has been achieved for many domains, including banking applications, electronic payment applications, and development tools.
Enabling a legacy system to interact within a Web services architecture is sometimes relatively straightforward—this is a primary attraction to the approach for many businesses. Web service interfaces are set up to receive SOAP messages, parse their content, invoke legacy code, and optionally wrap the results as a SOAP message to be returned to the sender. Many modern development environments provide tools to help in this process, and commercial organizations are rapidly employing these environments to expose their business processes to the world.
Characteristics of legacy systems, such as age, language, and architecture, as well as of the target SOA can complicate the task. This is particularly the case when migrating to highly demanding and proprietary SOAs. Such migrations will likely rely less on semi-automated migration and more on careful analysis of the feasibility and magnitude of the effort involved.
Such migrations also have to be considered from three perspectives: the application developer, the infrastructure developer, and the service provider. The needs and concerns of each of these participants have to be considered in order to develop successful systems based on SOAs, especially if these participants belong to different organizations, which is more and more the case.
The Service-Oriented Migration and Reuse Technique (SMART) offers the service provider a method for making an analysis of the effort, risks and costs that would be involved in making the migration of specific legacy assets to a specific target SOA.
SMART gathers information about the organization’s needs and expectations for the migration, the legacy components, the target SOA, and potential services, to produce a service migration strategy as its primary product. SMART considers the perspectives of the application developer and infrastructure provider in the development of the migration strategy.
This tutorial addresses the problem of the migration of legacy assets to a Service- Oriented Architecture (SOA). It addresses how to develop a realistic strategy for performing such a migration, taking into account both the needs of the organization and the technical content of the existing systems portfolio. A case study using the method provides a real world context for its applicability. Open issues and current research topics are outlined.
· Introduction to SOAs
· The Three Perspectives of SOA Development
· SOAs: Myths and Facts
· Reuse Issues
· Issues in Migration to SOAs
· SMART (Service Migration and Analysis Technique)
· Conclusions and Next Steps
Grace Lewis, Software Engineering Institute (firstname.lastname@example.org)
Grace Lewis is a Senior Member of Technical Staff at the Software Engineering Institute (SEI) of Carnegie Mellon University (CMU), where she is a part of the Integration of Software-Intensive Systems (ISIS) Initiative. Grace is currently working in the areas of technologies for interoperability, service-oriented architectures, Web services, modernization of legacy systems, and model-driven architecture. Her latest publications include several reports published by Carnegie Mellon on these subjects and a book in the SEI Software Engineering Series. She is also a member of the technical faculty for the Master in Software Engineering program at CMU. Grace holds a B.Sc. in Systems Engineering (1991) and an Executive MBA (1997) from Icesi University in Cali, Colombia; and a Master in Software Engineering (2001) from Carnegie Mellon University.
Dennis Smith, Software Engineering Institute (email@example.com)
PhD Dennis Smith is a Senior Member of the Technical Staff and Lead of the Integration of Software-Intensive Systems (ISIS) Initiative at the Software Engineering Institute (SEI). This initiative was launched in October, 2003 and focuses on developing and applying methods, tools and other technologies that enhance the effectiveness of complex networked systems and systems of systems. Previously, he was a member of the Product Line Systems Program and technical lead in the effort for migrating legacy systems to product lines. In this role his team developed the method Options Analysis for Reengineering, OAR, to support reuse decision-making. He has published a variety of books, articles and technical reports, and has given talks and keynotes at conferences and workshops. Dennis was the co-editor of the IEEE and ISO recommended practice on CASE Adoption, and has been general chair of two international conferences, IWPC99 and STEP99. Dennis holds an M.A. and PhD from Princeton University, and a B.A. from Columbia University.
29th Nov - 1st Dec