Wrapping legacy systems for use in heterogeneous computing environments

With the advent and widespread use of object-oriented and client-server tec hnologies, companies expect their legacy systems, developed for the central ized environment, to take advantage of these new technologies and also coop erate with their heterogeneous environments. An alternative to migrating le gacy systems from the mainframe to a user-centered, distributed object comp uting, and client-server platform is to wrap the legacy systems on the main frame and expose the interfaces of the legacy systems to the remote clients . The enabling middleware technologies such as Common Object Request Broker Architecture (CORBA), Component Object Model/Distributed Component Object Model (COM/DCOM), and Java RMI make the migration of the legacy systems to a heterogeneous distributed computing environment possible. In this paper, we present an approach and practical experience for integrating the legacy systems to a heterogeneous distributed computing environment by adopting th e CORBA technology. It has been reported quite often that an approach like this will improve system maintainability, portability, and interoperability . We also illustrate this approach with an industrial project. The project is viewed as a reengineering effort where a centralized reengineering syste m is wrapped to operate in a heterogeneous distributed computing environmen t by leveraging CORBA technology. The reengineering approach is a combinati on of redesign and simple facelift. The resulting legacy integration archit ecture through the application of the approach is evaluated using the equal ity attributes proposed by Bass, Clements, and Kazman. (C) 2001 Elsevier Sc ience B.V. All rights reserved.