What is the procedure in DFM Concurrent Costing's Injection Molding process to model co-molding?

For co-molding, the modeling process involves generating a DFM Concurrent Costing analysis for each of the two shots. First, complete an analysis of the base part as it is initially molded. When conducting this analysis, the part volume and projected area inputs should correspond to the volume and projected area of the base part prior to the second shot. The number of surface patches input should also include the number of surface patches on the runner system molded into the base part to accept the second material. After completing this analysis, the base part will be used as an insert in a second injection molding analysis. Start a new analysis, for instance on a second tab in the same file as the base part analysis. In the new analysis, enter the envelope dimensions of the finished part including the base part. When defining the volume and projected area, include only the volume and projected area of material added during the second shot. When defining the surface patches, include the surface patches added by the second material as well as enough surface patches to hold and support the base part in the mold during the second shot. When entering the maximum thickness value for the added material, enter two times the actual thickness of added material. This will account for the fact that the added material will be cooled by the steel mold from one side while it is insulated by polymer on the other. When entering the cost of mold inserts per part for the second analysis, enter the total cost per part generated by the analysis of the base part.