This section is from the "Modern Machine Shop Construction, Equipment, And Management" book, by Oscar E. Perrigo. Also see Amazon: Modern Machine Shop Construction, Equipment, And Management.
The desire of the employer to make the rate as low as possible, or at least so that the workman should be able to earn little more than day pay, yet to turn out considerably more work.
The desire of the workman so to manipulate conditions as to get as high a rate as possible notwithstanding his past experience that "a cut" would follow. All this is wrong in theory and worse in practice. The ethics of good business teaches us that no plan of adjusting the differences between the employer and the workman will long endure and give satisfaction that does not equitably provide for the mutual financial benefit of both parties without encroaching upon the rights of either. This is no visionary theory, but rather a condition that may be realized if proper methods are pursued and modern systems made use of. The importance of the question demands the greatest care and consideration in its solution. Like the development of all valuable methods and systems, it will cost something, although it should not be expensive as compared with the benefits that will accrue from it.
There are three methods for accurately determining equitably the piece work rate for the workman. The first method is that described of using the output of a workman on a day rate basis.
The second plan is to have the work done, not by the men who are afterward to do the work at the piece work rate determined, but by two different reliable and skilled mechanics, and then to average the results. This makes a much fairer, but usually a rather close rate when the work is done by the average operator.
The third plan is to carefully calculate the time of every movement in the various operations and to simplify them until every unnecessary waste of time is carefully eliminated. This is called a "Time Study," and its final determinations are then incorporated in a "Shop Operation Sheet," which is used as a guide by the mechanic who does the work. This is really an equitable plan and perfectly fair for both sides, and both the employer and the workman must admit it to be the only scientific plan yet devised for such work.
By the use of the second plan the tendency is to attract to each class of work the men best fitted for the job. A good man will increase his output from 30 to 50 per cent, when working with the same machine and tools that he would use in day work. He will also perfect his methods and probably improve his tools somewhat, if he is assured against a cut in the rate, if by his ingenuity, ability, and energy he exceeds the expectations of the official who fixes the rate. He should be permitted to increase his output 50 per cent if he can do so and still produce good work.
It may seem easy to avoid the dissatisfaction over cutting rates by first setting a rate low and then raising it gradually until the proper point is reached, since workmen never object to the rate being raised. There are, however, valid objections to this method. Days and sometimes weeks will be spent in acquiring the data for these adjustments on a single piece, and the larger the number of different pieces handled the greater will be the time required and expense incurred. Other considerations will also enter into the matter. For instance, the overhead or general expenses, and the hourly rates upon machines, both of which will be seriously affected by the fluctua-tions of the output of the machines. The fact should not be lost sight of that any plan which tends to increase the output of machines, even while increasing the pay roll considerably, is usually more than counterbalanced by the lowering of the overhead expenses as considered pro rata with the value of the product.
The matter of accurately and intelligently fixing the price or a fair rate of machine operations is entirely practicable. Let us assume that we have a lot of cast iron chuck plates to finish in an ordinary engine lathe. This is taken as an example of an easy and simple job for illustration. In Fig. 212 is shown the sixteen different operations, and for purposes of analysis the chucking and mounting; in fact, each step up to the final removing of the piece from the lathe. To obtain a proper rate for this work it will be put in the hands of a fairly good workman and the time occupied in performing each operation will be noted by a time-study man, who observes the work, watch in hand, and notes the elapsed time. Being expert at this duty he will know if there is any unnecessary loss of time, and if he is not satisfied with the progress of the work, he will require the set of operations to be performed a second time. This will give a fair and accurate account of the elapsed time, which may be safely used in calculating the piece work rate. These conclusions may be checked by having the operations performed by a second man and the time averaged as between the two.
1. Chucking by the Hub.
2. Facing, Front of Flange.
3. Turning Flange.
4. Chucking by the Flange.
5. Turning Hub.
6. Facing Back of Flange.
7. Facing Hub.
8. Roughing out Hole.
9. Reaming Hole.
10. Counterboring Hole.
11. Reaming Counterbore.
12. Cutting Thread.
13. Size Tapping Hole.
14. Mounting on Spindle.
15. Facing Flange.
16. Turning Flange.
Fig. 212. Consecutive Operations in Machining a Chuck Plate.
Many of, these operations can be calculated without the work being actually performed. For instance: turning cast iron, using tools of highspeed or self-hardening steel, may be done at a speed of 50 to 60 feet per minute, and a feed, on a roughing cut of 8 or 10 revolutions per inch, and on a finishing cut 15 to 25 per inch. In Fig. 212 roughing and finishing cuts are not shown separately, but it is to be understood that both are included, and that sometimes three cuts may be necessary, namely, roughing, sizing, and finishing.