Version Storage Control Strategy in Collaborative Design Based on STEP

Version management of Computer Support Collaborative Design(CSCD) must store all version of design during the course for inquire and search.With full storage,versions access fast,but they take up huge storage space and have a mass of storing redundancy information of version.Difference storage can save storage space,however,with a slow versions access speed and depressed security.This paper proposes two models of difference storage based on STEP,and combines difference storage and full storage by constructing storage threshold function,so space efficiency and time efficiency are balanced effectively.