The paper presents a speculative model of the growth and development of an occupational education program as it responds to changes in student interests and job market conditions. Informal discussions with the directors of several occupational schools in Massachusetts provided the base for the model. Intended as a tool for educational managers, to stimulate new thinking about policies and practices, the model can be described in precise mathematical terms, so that computer simulation can be used to test various policies and hypotheses. Not a detailed description of any single program, the discussion emphasizes aspects of all such programs important for an understanding of any single program. The model is experimented with, using different potential employment curves, and the response is shown for each of three possibilities. The study is framed in the system dynamics methodology of Jay W. Forrester, explained in the appendix, where a precise mathematical formalization of the assumptions discussed is given. (Author/AJ)