Empowering CAPP Systems with Human-Computer Interaction Study

Initially designed to fill the gap between CAD and CAM systems, computer aided process planning (CAPP) systems have reached very limited success and acceptance in industry. To explain this assessment, some researchers point out the fact that most existing approaches aim at complete automation, and suggest that CAPP systems should integrate the human planner into the decision-loop to improve its flexibility and efficiency. For instance, such systems should provide some relevant information about alternative plans rather than automatically computing one unique plan. The objective of the present paper is to provide some results about the efficiency of such alternative proposal from a human-computer interaction point of view. Our work is based on an existing set-up planning method. Human decision-making is necessary because no accurate optimality metric has emerged to automatically select the set-up positions among the computed alternatives. This paper deals with the design and early evaluation of the future user-interface of a set-up planning module. A mock-up of the human-computer interface has been designed to drive the evaluation. This evaluation points out that the number of alternatives solutions should be limited. This paper suggests this limitation is due to either of two factors: human limitation in information processing and industrial constraints in the process planning activity. To conclude, the relevancy of this proposal in an industrial context is discussed