This paper describes informally a comprehensive systems model that could aid school program decision makers. The model, a multistage input-output scheme, permits descriptions of social, political, economic, and educational interactions in an urban school system for the purpose of defining the school system performance and its amenability to change and reform. The model also makes it possible to define levels of financial support given to different schools, and to correlate these findings with student and family characteristics. The model would permit exploration of the interrelationship between various outcomes and inputs, such as student achievement and per pupil expenditures. Description of the demands and supports deriving from a variety of community and political groups is also possible. The model is being applied in Wilmington, Delaware. (Author/DE)