AbstractThis paper sets out to show how accountants and OR model builders can constructively combine their different points of view to produce real benefit through the use of relatively simple computer models. The situation of Coal Products (the process subsidiary of the NCB) is described, together with the rationale for experimenting with models in the first place. Then the approach and construction of several models is outlined, in particular models for projecting a coking plant profit and loss and a corporate model which considers both profit and loss and cash flow. Final sections discuss the use and value of the models and suggest some lessons from the continuing experience.