Part 17

Take a simple job like the assembly of a license bracket in an automobile factory. An analysis of this operation (see "Micromotion Technique," by F. J. Van Poppelen, Factory and Industrial Management, Nov., 1930) showed that the right hand was busy all the time, while the left did nothing most of the time except hold the piece.

At the risk of getting too technical--for after all we are interested, not so much in the details, as in certain broad principles of organizing the work--let us see how the operation was performed.

First the operator assembled a number of screws and leather washers by picking up a screw with the left hand, a washer with the right, putting them together and laying the assembly aside. Then he picked up a bracket with the left hand and a screw and washer assembly with the right, placing the screw through a slot in the bracket--continuing to hold assembled pieces in his left hand while the right was picking up a flat washer and assembling it to the screw; picking up lock washer, assembling it to the screw; picking up acorn nut and starting it on the screw; and finally picking up an open-end wrench and tightening the nut. Then he assembled screw, washers and nut to the other side of the bracket, whereupon wrench and bracket were laid aside, completing the cycle.

An analysis of these motions, by right and left hands, is given in the table on page 120. It illustrates the important point that the right hand was busy all the time, but for a considerable part of the time the left was doing nothing but holding the piece.

On pages 118 and 119 are shown drawings of the old and the new assembly methods. Likewise, the lower table on page 120 analyzes, by right and left hands, the motions required by the new method. Note first that fewer elements--17 as against 26--are required. And note that both hands are productively employed with shorter distances to travel for stock and with decreased effort.

Analysis of this assembly job shows ...

... that the right hand was busy all the time....]

Comparison with the old method

... shows both hands productively employed....]

TABLE 1

LEFT HAND RIGHT HAND

1. Pick up screw Pick up leather washer 2. Assemble Assemble 3. Idle Lay aside 4. Pick up bracket Pick up screw and washer assembled 5. Hold bracket Assemble 6. " " Pick up flat washer 7. " " Assemble 8. " " Pick up lock washer 9. " " Assemble 10. " " Pick up nut 11. " " Start on thread 12. " " Pick up wrench 13. " " Tighten nut 14. " " Lay wrench aside 15. " " Pick up screw and washer assembled 16. " " Assemble to other side of bracket 17. " " Pick up flat washer 18. " " Assemble 19. " " Pick up lock washer 20. " " Assemble 21. " " Pick up nut 22. " " Start on thread 23. " " Pick up wrench 24. " " Tighten nut 25. " " Lay wrench aside 26. Idle Lay bracket aside

TABLE 2

LEFT HAND RIGHT HAND

1. Pick up screw and transport Same 2. Position on block Same 3. Pick up leather washer and transport Same 4. Position on screw Same 5. Pick up new bracket and transport Pick up assembled bracket; lay aside 6. Position bracket on block Same 7. Pick up flat washer and transport Same 8. Position on screw Same 9. Pick up lock washer and transport Same 10. Position on screw Same 11. Pick up nut and transport Same 12. Start nut on screw Same 13. Position driver Same 14. Tighten nut Same 15. Position driver to 2nd nut Same 16. Tighten nut Same 17. Release driver and move assembled bracket 2 in. forward on block Same

The new set-up consists of a hardwood block, shaped to fit one side of the bracket when assembled, and nailed to the bench. The open-end wrench was replaced by a screw-driver with a socket wrench to fit the acorn nut, suspended on a spring in front of the operator. The miscellaneous containers for holding the small parts were replaced by a supply of sheet-metal duplicate trays, so that the various parts could be located in the most convenient position. (This arrangement was not used in the accompanying illustrations because it obscured the view.)

In a word, then, the number of elements was decreased by one-third--and practically all of the elements in the new method require less time than the similar or corresponding element in the old method. The distance of travel for stock has been shortened, parts are grasped more easily, better and faster tools are provided, effort is decreased, and both hands are productively employed.

Need the imagination be stretched to the breaking point to see how a job involving the work not of one man, but of several, may be similarly organized and similarly improved?

A second illustration will serve to show the application to group work (see "Motion Study Applied to Group Work," by J. A. Piacitelli, Factory and Industrial Management, April, 1931, page 626).

The operation studied here involved cycles of approximately eleven seconds' duration, performed by a group of seven men. The material handled consisted of rolls of roofing weighing about 50 lbs. each. Many of the elements in the cycle were obviously fatiguing. The rolls had to be lifted, during transfers from one worker to another, and rolled along a horizontal runway. The trucker lifted the completed roll and placed it on his truck. While the rate of production was limited by process and speed of equipment, the chance to cut cost and fatigue prompted the study.

Examine the equipment layout before the study was made (it is shown on page 124), and follow the operation. A roll of roofing paper approximately 8 in. in diameter and 36 in. long was wound about the mandrel of a winding machine by one of the workers. The roll was taken off and passed to another worker who wrapped a sheet of paper about it and pasted it in place. When the roll was wrapped, he had to lift the roll, turn and deposit it on the runway. The next man inserted a bag of nails, a can of cement and an instruction sheet into the core of the roll. To do this, he was forced to turn and bend almost to floor level to get his supplies.

Next the roll was passed along to two men who, from opposite sides of the runway, placed protectors and muslin caps on the ends of the roll. It was then rolled along to another man who placed gummed paper bands about the ends and pushed the roll to the end of the runway where the trucker placed it on a truck and wheeled it into storage.

The movie camera, which is gradually finding wider industrial use in the search for the "one best" method, was used to record the work of this group. It supplied not only a photographic record of the working place and surrounding conditions, but also a simultaneous record of time and method employed by each worker regardless of speed. It was then possible to study overlapping cycles and to analyze the methods to the desired degree of accuracy--and thus to transfer parts of the cycle of one operator to that of another, thus effecting a better distribution of work and shortening the cycle of the person on whom the production of the group depends--thereby increasing the productivity of the entire group.

These analyses showed immediately an unequal distribution of work. Again, from the equipment layout made after the study, let us follow through and see what changes were effected.

First the wrapper was freed from turning and lifting the roll from his table by the introduction of an elevator which lifted the roll to an inclined runway. The roll then moved from place to place by gravity when released by foot-operated trips. The pasting problem was solved by using a trough the length of the paper, open on the bottom and equipped with squeegee lips like the mucilage bottle on your desk. A pile of wrapping paper with the far edges of the sheets inserted under the trough supplied a pasted sheet every time one was drawn toward the operator. The trough was covered with a hinged plate which permitted the roll to pass over it to the elevator. It was found, by eliminating the fatiguing elements in this man's work and simplifying his cycle of motions, that the time would be so reduced that he could easily take over the work of the man who placed the cement and nails in the core of the roll. The instruction sheet was placed in the roll by the winder, who had ample time for this additional task. The pile of sheets was placed at his right under a date stamp so that he could date each sheet and slip it into the roll just before it stopped.

Simplifying the cycle of the men who placed the caps on the ends of the roll enabled them to take over with ease the work of the man who had placed the gummed-paper bands around the ends. Thus each man capped and banded his own end, whereas formerly the bander had had to assume an awkward and fatiguing position to reach the far end. And last, by placing a redesigned truck at the end of the incline, the completed rolls landed in the truck, and the trucker was able to care for two machines.

The method finally established was recorded on instruction sheets, and the existing premium was modified to provide additional incentive. Although, as stated at the outset, the rate of production was limited by the machine, substantial savings resulted from the study. Production has been maintained with 4-1/2 men instead of 7; fatigue has been greatly lessened; cost has been reduced about 26 per cent; average earnings of the group have increased about 19 per cent.

Thus the search for the "one best" method becomes an important factor in organizing the work.