Ioa S. Gavrila, Bert Bredeweg, and Piet Iedema
In this paper we illustrate the use of qualitative knowledge and reasoning to conceptual process design. For a certain class of chemical processes, we propose a design method in which qualitative and numerical decision making phases are alternated. Qualitative reasoning is performed when a rough scan of many design alternatives is desired; numerical decision making follows only for the promising looking qualitative alternatives. In all design phases Propose-Critique-Modify tasks are performed, to quickly evaluate design decisions and to prevent thus the entrance in unfeasible or sub-optimal parts of the design search space. A modular knowledge-based system has been implemented in which the modules follow the task decomposition of the design method.