Developing legacy system migration methods and tools for technology transfer

Abstract

This paper presents the research results of an ongoing technology transfer project carried out in cooperation between the University of Salerno and a small software company. The project is aimed at developing and transferring migration technology to the industrial partner. The partner should be enabled to migrate monolithic multi-user COBOL legacy systems to a multi-tier Web-based architecture. The assessment of the legacy systems of the partner company revealed that these systems had a very low level of decomposability with spaghetti-like code and embedded control flow and database accesses within the user interface descriptions. For this reason, it was decided to adopt an incremental migration strategy based on the reengineering of the user interface using Web technology, on the transformation of interactive legacy programs into batch programs, and the wrapping of the legacy programs. A middleware framework links the new Web-based user interface with the Wrapped Legacy System. An Eclipse plug-in, named MELIS (migration environment for legacy information systems), was also developed to support the migration process. Both the migration strategy and the tool have been applied to two essential subsystems of the most business critical legacy system of the partner company.

Bottom-up and top-down COBOL system migration to Web Services: An experience report

“…Community's experience confirms that SOA and Web Services are a right target for migrating legacy systems, specially when loose coupling among providers' and clients' systems, and agility to respond to changes in requirements [1] are needed [2,3,4]. The reported experiences show two main migration approaches, namely Direct and Indirect Migration [2].…”

Empirical validation of the Classic Change Curve on a software technology change project

“…There were not too many alternatives to doing things this way, since all the data had to be transferred from the old system to the new one, and the system service break had to be minimized. In the literature, numerous systematic legacy information system migration strategies can be found [e.g., 9,14,20,22,69], as can a taxonomy of strategies [10]. Based on the Bisbal et al [10] taxonomy, the ADPC redevelopment approach was a revolutionary one as the new system was developed from scratch using a new hardware and development environment.…”

The SOAMIG Process Model in Industrial Applications

“…Activities in migration projects include legacy analysis (e.g. program comprehension, identifying reusable software assets), and legacy conversion [7]. Next to these reengineering and reverse engineering activities, evolution projects address target and legacy architectures and require migration strategies.…”

“…Choosing the most suitable migration strategy is an important step (cf. [7]). Performing iterative migrations also includes deciding on the parts of the system to be migrated in each iteration.…”