Decision Space Modeling and Implementation for Product Design

The granularity is used to describe product design knowledge based on the concept of rough degree in rough the ory.The knowledge dependent relation diagram is put forward,both the n-dimensional knowledge granularity decision space and the same construction mapping decision space based on mult-i decision sorts are established,and the decision algorithm is furthe r presented.Finally,by combining with the choice decision of ball bearing the practicability is proved.