Object-oriented technology has been around for over thirty years and offers some significant improvements over structured techniques and procedural languages. It has seen very slow growth in business applications, but is expected to grow at such a rate as to nearly replace those systems now being used at some point in the near future. It represents a paradigm shift that is difficult to master for both novice and experienced IS personnel. Radical changes, such as OO, force changes in the thought and work processes of workers and generally wreaks havoc in the workplace. Using the organizational psychology theory of Person-Environment fit, this study proposes a model to explain the behavioral performance and the amount of stress felt by a person in their workplace when undergoing a paradigm shift. The shift to OO is used as the test case for the model.