Computer-aided software engineering (CASE) tools have generated much interest as potential means for easing the software development and maintenance bottleneck. To date, the picture regarding their contribution is incomplete and confused, particularly concerning the realization of productivity and quality gains. An in-depth study of one company's experiences with the introduction of CASE is described. Quantitative data is available to allow objective comparison of changes in productivity and IS quality consequent upon the CASE introduction. Questionnaires were used to determine the perceptions of both developers and their customers to the new methodology and tools. The importance to the successful introduction of CASE of the human resource, technical, and managerial infrastructural factors are also investigated.