An approach to gradual migration from legacy applications

• Grant number: 03/07851-4
• Support Opportunities: Research Grants - Innovative Research in Small Business - PIPE
• Start date: May 01, 2004
• End date: December 31, 2004
• Field of knowledge: Physical Sciences and Mathematics - Computer Science - Computing Methodologies and Techniques
• Principal Investigator: Andre Luis Costa de Oliveira
• Grantee: Andre Luis Costa de Oliveira
• Company: Apyon Technology S/A
• City: São Paulo

Abstract

An Approach to Gradual Migration from a Legacy Applications Software System is an evolutive artifact. With the passage of time, its original design and implementation are modified to meet new requirements and/or to improve its performance, incorporating substantial new knowledge into its context. This process is called constant maintenance. But after four years, approximately, applications become legacy, since the technology on which they were based are out-of-date and in the majority of cases no longer supported by the manufacturers. Legacy applications contain program logics, project decisions, users’s requirements and business rules that need to be recovered, interpreted and converted, which corresponds to approximately 25 per cent of the application’s complexity. The remaining 75 per cent is related to technological aspects, such as transactions, connections, databases, components and graphic interfaces. One of the forms currently used for the reconstruction of pieces of software is total and direct migration from the legacy application. This type of migration demands a great deal from the software engineers, who need to have as much knowledge of the technology used in the legacy application as that used in the new application. Furthermore, legacy applications generally don’t possess documentation. An alternative for the reduction in time and complexity in the migration from legacy applications would be the identification and separation of rules that govern business and technology. This separation would permit the gradual migration from the legacy application and coexistence between the legacy application and part of the reconstructed application, lending flexibility to the migration. Therefore, the objective of this project is to make migration from legacy applications viable and secure for businesses.What is proposed is an approach to gradual migration, guiding the software engineer in the reconstruction of that application and integrating tools and new techniques such as, for example, Refactoring, Web Services and EAI. (AU)