One workman under the old system could attend the leaf through all these phases, or even make a complete spring, but his production would be limited. Where large quantities of the same article are to be made, the simplest operation may involve the whole time of one man. A one-minute operation will require one man a full day of eight hours to accomplish it on 48o pieces. Now this simple part, a spring leaf, must be identical in strength, finish and curve with millions of others designed to fulfil the same pur pose, and this becomes a complicated and delicate procedure re quiring automatic machinery, the most accurate of measuring de vices, pyrometer controls, "go" and "no go" gauges—in fact, the best facilities that can be provided by modern management. The leaf described, which is a minor matter when compared with the whole great process, becomes a major matter when considered by itself ; it must have its own supply of material delivered in suffi cient quantities at indicated places—for example, steel at I ; heat at 2 ; power and oil at 3; heat at 5; water at 6; bolts at 7; lubri cants at 8; bolts at 9; nuts at 1 o; clips at 1 1. In this process the secrets of many arts and trades are employed.
The story of this minor part illustrates what is meant by orderly progression of the article through the shop. It goes to meet other parts of the motor-car which have come from other parts of the plant by similar processes. The story illustrates also what is meant
by delivering the work to the workman: every workman's task is prepared for him by some other workman, and delivered to his hand. The third principle also is illustrated—the analysis of a single job into its constituent operations. The simplicity of the part here described should not be permitted to exclude from view the multitude of other operations, ranging from the heaviest forg ings to the lightest manipulations in bench assembly of delicate electrical instruments. Some gauge inspections involve measure ments to the ten-millionth part of an inch.
The economies arising from this method are obvious. The ma chinery is constantly in use. It would be economically impossible to maintain all this equipment for the service of men occupied in the entire operation of making springs. Presses, furnaces, bending machines, oil baths would be idle while the workman progressed from operation to operation. Under mass production it is the work, not the man, that progresses from operation to operation. Otherwise use-convenience in the commodity would be lessened, while price-convenience would be destroyed. There is also the economy of reduced inventories, in lapse of time between raw ma terial and finished product. Mass production justifies itself by an economy whose benefits may quickly be transmitted to the pur chaser.