The current competitive business environment has forced organizations to consider business process reengineering (BPR) in the quest to achieve dramatic improvement in their organizational effectiveness. The purpose of this study was to develop an evolutionary and dynamic BPR model referred to as Process Reengineering Integrated Spiral Model (PRISM). Through an extensive review of existing BPR models and a critical analysis of their limitations, PRISM was formulated to overcome problems associated with conventional BPR models. PRISM was based on theory related to evolutionary approaches which were deemed suitable for BPR. It is a natural way of working for BPR modelling because the process redesigner is involved in, and takes account of, the real world context. PRISM is also adaptable to a rapidly changing business environment in a situated and open-ended manner. This thesis motivates and illustrates the PRISM approach to new principles of evolutionary BPR. The aim of this concept is to address the well-known high failure rate of BPR. The famous Boehm's software engineering spiral model was extended to develop PRISM in the context of evolutionary BPR.