In mould structure predesign, there are several issues to be considered, which include identifying all undercut features in a moulded part, determining the optimal parting direction and generating the parting lines and parting surfaces. Besides these, it is also necessary to determine the following options.(1) Mould types: moulds can be two-plate or three-plate. It can also be hot, cold or conventional sprue mould type based on the diŒerent runners used.(2) Number of cavities and cavities layout: the cavity’s layout can be star, symmetrical, in-line arrangement or others.