| The builders of large-scale computer-based systems use customer needs and established systems architecting and systems engineering processes to guide their initial architecture definition and system design. Years later, however, when considering a major upgrade or replacement of the system, the engineering process used for its initial design and development may be inadequate as the basis for a reengineering program.;The purpose of this inquiry is to identify the elements of legacy system reengineering required to conduct a reengineering project whose goal is the modernization of an aging legacy system.;The review of the literature covers academic texts on formal systems engineering methods to identify how they accommodated reengineering, articles on reengineering concepts and practices to understand how practitioners are conducting reengineering projects, lessons learned from reengineering projects describing their important tasks, and additional topic areas that have a role in, or influence, reengineering projects, as described by authors.;The analysis was conducted using data gathered through a survey of engineering professionals. The analysis objective was to identify the elements of legacy system reengineering by determining their importance to engineering practitioners and managers when conducting a legacy system reengineering project. Key findings are that the two processes are different, as measured by Eisner's 30 elements of systems engineering, and that the engineering elements considered important for reengineering are different than those considered important for engineering.;This research identified 21 elements of systems reengineering. They consist of 16 elements from Eisner's list of the 30 elements of systems engineering, and five new elements, identified as a result of the review of the literature, that were rated important for reengineering: two new elements deal with the tasks to recover information residing in the operational legacy system, three describe activities to recover the legacy system's requirements, architecture, or design via abstraction. |
