the process for investment casting of complex shapes has historically had 6 basic steps in it . depending upon the path taken , these discrete steps have been reduced to either 5 steps , or to 2 steps , discarding the unwanted steps . instead of having to generate the shape of each sacrificial pattern , the process generates either a male tree containing a plurality of sacrificial patterns , already on their runners , onto which a mold shell can be formed , or , a female shell , made of a refractory material , and forming internally the outside surfaces of the plurality of patterns and runners . this process removes both capital expenditure for tooling and process time by up to 90 %. by removing several lengthy , time - dependant steps from the process the part cost and lead time are reduced .