The research reported in this paper involved the study of end-user computing in typical organizational settings. An extensive literature review was conducted and a number of executives consulted about the effects and position of the end user computing phenomenon within their organizations. The data served as a basis for a system dynamics model that focused on the forces that create growth in end-user computing. The “tiered infrastructure” of computing in the organization is demonstrated and discussed. One problem with the study of end-user computing has been the lack of testable theory about it. The majority of research has used case studies or relatively narrow field studies as a methodology. The key purpose in using the system dynamics approach has been to provide a vehicle to capture the ideas cataloged in the various case studies and cast them in the causal map format as a dynamic theory of systems organization and behavior.