A SYSTEM FOR DESIGN AND CONCURRENT ENGINEERING UNDER IMPRECISION

This paper proposes an approach to handling imprecision in design and concurrent engineering systems by using interval analysis and constrai nt networks. By allowing design parameters to be specified with interv als rather than exact points, this approach permits designers to itera tively transform vague conceptual designs into detailed final designs. When a designer changes a variable's interval or assigns a value, the results are propagated through constraints and the resulting feasible interval for all other dependent variables is pruned. The interval co nstraint network approach described in this paper extends previous wor k by allowing the representation of and reasoning about complex constr aints involving conditions, conjunctions and disjunctions, as well as both symbolic and numeric variables. Many concurrent engineering const raints cannot be modeled without this sort of representational flexibi ity. A prototype of this approach has been implemented in a system cal led SPARK-IP. The operation of SPARK-IP is demonstrated through a conc urrent engineering design problem involving printed wiring boards.