Abstract This paper outlines new development in the design of Decision Support Systems and Mill Wide control. These developments have been implemented .in a system for a board mill at Thames Purfleet whose management worked closely with the university based Systems Group at Imperial College. The system design to control a multiproduct plant producing a range of reels, sheet and board in various dimensions, consistency, colour and surface finish. It uses advanced procedures for scheduling, deckling, sales forecasting and stock control and employs an advanced “what-if” evolutionary simulation for prediction, management decision support and production control via a terminal network. The system has rapid “conversational” response.