AbstractThe paper describes how a number of proposed deep-water port developments for importing ore for the British Steel Corporation were assessed. The study was divided into two stages: the first stage was used to identify the best available options against a background of uncertainty by considering one year in a changing future; the second stage was used to evaluate the best proposals in detail and plan a course of action.The investigating team was heavily involved throughout in the managerial aspects of planning and decision-making. Where appropriate the effects of this participation are described and from them corresponding lessons drawn.