The Simulation Option Model (SOM) was developed as part of the Centre for Educational Research and Innovation work on educational planning. Its two main purposes are to be an analytical tool for the project on Educational Growth and Educational Opportunity and to be a direct contribution to member countries' own work in these areas. The model includes predictions about future numbers of students in various parts of the system and outflow from the educational system; future resource requirements, both physical and monetary; future supplies of teachers in various categories; and future relationships between teacher supply and teacher requirements. The paper provides a brief overview of the model's submodels--flow, resource, teacher supply, and teacher comparison--and of an application study. Appendixes provide more detailed information, including flow charts. (Author/IRT)