Legacy System Migration : A Legacy Data Migration Engine

The widespread use of computer technology over several decades has resulted in some large, complex systems which have evolved to a state where they significantly resist further modification and evolution. These Legacy Information Systems are normally mission-critical : if one of these systems stops working the business may grind to a halt. Thus for many organisations, decommissioning is not an option. An alternative solution is Legacy System Migration which has recently become an important research and practical issue. This paper presents an approach to mission-critical legacy systems migration: Butterfly methodology. Data migration is the primary focus of Butterfly methodology, however, it is placed in the overall context of a complete legacy system migration.