Constraint Reasoning and Planning in Concurrent Design

Abstract

By concurrent design we mean. in pan, concurrent consideration of a broad range of life-cycle constraints concerning, for example manufacturing and maintenance. The multitude of constraints arising from these considerations make it difficult to identify satisfactory designs. An alternative to explicitly considering all constraints is to determine which of the constraints are relevant, redundant or inconsistent and to consider only those which impact design decisions. The proposed approach is based on two simple ideas: (1) Constraints provide a uniform representation for a variety of life-cycle concern. and (2) Internal methods applied to constraints can be used to identify critical constraints. eliminate redundant constraints and to narrow the space of design alternatives. The application of the necessary and sdcient intervals of constraints and constraint propagation techniques are used to classify constraints in this way and to focus design activity. Regional monotinicity properties are used to identify critical constraints. A related aspect of concurrent design problems is the large number of complex constraints which have to be satisfied to complete a design task As it is impossible to guarantee the simultaneous solution of a large set of design constraints, we have investigated algorithms for planning and simplifying such constraint problems.