Understanding legacy information systems and abandonment decision making: Towards methodological support

Like other systems, information systems (IS) age and at some point in time, they are referred to as legacy IS. A legacy IS is defined as “any IS that significantly resists meeting organizations’ requirements”. This dissertation describes the complex process of aging IS, including the identification of 149 legacy IS aging characteristics, categorized into internal or external aging factors. Internal aging factors were within the control of the organizations and could be influenced and external aging factors remained outside the control of the organization and could not be influenced. Furthermore, 38 abandonment triggers have been identified that make organizations decide to actually abandon legacy IS. It is concluded that both legacy IS aging factors and the legacy IS aging triggers accumulate and deteriorate IS. In legacy IS abandonment decision making, three eclectic decision making perspectives were predominant: the functional, the technical and the economical perspective. Further, this research identified many abandonment decision making good practices and good practices concerning the practical abandoning of legacy IS. Finally, a decision support method how to abandon legacy IS is proposed