Requirement 3: Production quantity of 100,000 graters.
1. One green sand casting can be used to produce up to 10 parts per mold, as the mold will have defects after several parts has been casted. So, for a production of 100,000 parts, a minimum of 10,000 molds have to be manufactured. Also, only one part can be casted at one time, which highly slow the process of making all the parts.
2. Using the investment casting method, the mold too will have to use multiple molds to cover the quantity of 100,000 graters. By looking at the size of the grater, we assumed that each mold can produce up to from 20-30 parts for each mold. So, a minimum of 5,000 molds needed. The 20-30 parts can also be made at the same time, which will save time.
3. For die casting, it is usually being done by using a permanent mold. This will results in having a high production rate, plus all 100,000 parts needed can be manufactured from one single mold. The high rate will also turned out to save a lot of production time.
Requirement 4: Lowest total cost.
Cost played a big role in which casting method is to use as manufacturer would try to minimize the production cost in order to maximize their profit.
1. Green sand casting: The cost for each mold is low because green sand is a cheap material. It also uses low cost material for its equipment. The labour cost too costs low as no professional worker is needed. But, as stated in requirement 3, this method will use 10,000 molds. This will highly affect the cost. Then, we’ll need 10,000 as many materials for molds and equipment, and also the workers. So, all cost including mold cost, equipment cost and labour cost will be high for each to making each part.
2. Investment casting: Individual mold will have a high cost due to the small details in the mold that have to be produced. Each equipment will cost high as plastic pattern which is needed for is very expensive. The labour needed is low, with the same reason that only