Qumquad: a UML-based approach for remodeling of legacy systems in health care

Objective: Health care information systems still comprise legacy systems to a certain extent. For reengineering legacy systems a thorough remodeling is inalienable. Current modeling techniques like the Unified Modeling Language (UML) do not offer a systematic and comprehensive process-oriented method for remodeling activities. Method: We developed a systematic method for remodeling legacy systems in health care called Qumquad. Qumquad consists of three major steps: (i) modeling the actual state of the application system, (ii) systematic identification of weak points in this model and (iii) development of a target concept for the reimplementation considering the identified weak points. Results: We applied Qumquad for remodeling a documentation and therapy planning system for pediatric oncology (DOSPO). As a result of our remodeling activities we regained an abstract model of the system, an analysis of the current weak points of DOSPO and possible (partly alternative) solutions to overcome the weak points. Discussion and conclusion: Qumquad proved to be very helpful in the reengineering process of DOSPO since we now have at our disposal a comprehensive model for the reimplementation of DOSPO that current users of the system agree on. Qumquad can easily be applied to other reengineering projects in health care.