As part engineering department of an automobile radiator manufacturer, an engineer in conceptual design phase is required to select material that will be used for its commercial off-the-shelf product.
This material selection shall consider the total life cycle of the car.
The design engineer has alternatives of using either a brass-copper alloy casting or a plastic molding. Either material provides the same service. However, the brass-copper alloy casting weighs 25 pounds, compared with 20 pounds for plastic molding. Every pound of extra weight in the automobile has been assigned a penalty of $6 to account for increased fuel consumption during the life cycle of the car. The brass-copper alloy casting costs $3.35 per pound, whereas the plastic molding costs $7.40 per pound. Machining costs per casting are $6.00 for the brass-copper alloy.