If the standard quantity per hour be 20, and the worker is on the job 8-1/2 hours, then the standard quantity for that time is 20 x 8-1/2 = 170. If the worker produces 170, his efficiency is (170 x 100)/170 = 100 per cent. Suppose he produces 200 in the time, then his efficiency is more than 100 per cent., because he has produced more than the standard quantity. His efficiency is (200 x 100)/170 = 117.5 per cent. If, on the other hand, he produces less than 170, say 150, his efficiency is (150 x 100)/170 = 88.25 per cent. RULE II.--In calculating efficiency by this method, it is evident that the quantity produced in a certain time must be multiplied by 100 and divided by the standard quantity for that time. If a definite number of articles are to be machined, the whole quantity may be looked upon as a single job. For instance, suppose there are 3,000 pieces to be produced, and standard quantity is 150 per hour. Then the _standard time_ for the whole quantity is 3000/150 = 20 hours. _Reward time_ will be 20 + 33-1/3 per cent. of 20 = 20 + 6-2/3 = 26-2/3 hours. Efficiency may now be worked out by the first method. Efficiencies are, of course, calculated on the _net time_--that is, on the total time of the job after day time and other allowances have been deducted. PART III EXPLANATION OF DIAGRAMS SHOWING DIFFERENT METHODS OF REWARD PAYMENT CHAPTER V REWARD AND EFFICIENCY In order to illustrate the general principles of the Reward System, an individual case was taken and one particular relation between reward and standard times was selected--namely, 75 per cent. The sewing on of buttons, the laying of bricks, ploughing, shipbuilding, etc., would have served just as well, and the same general results would have been obtained. The relation between reward and standard times has given rise to much discussion and experiment, and the relation selected in Part II. is one that appeals most strongly to the worker as he gets paid for all the time he saves. If reward begins earlier and the worker gets a proportion of the time he saves instead of the whole, reward at standard time should be just the same, or nearly so. It only means that the worker has a better chance of getting a higher reward when he is below the 100 per cent. line, and a smaller one when he is above it. The following diagrams show the relation between reward and efficiency according to the principal methods in use at the present time, some of them being used in the same factory for different classes of work. A complete diagram is illustrated on p. 88, but, for convenience, only a portion of this is used in most of the other diagrams. It must be noted that reward at standard time must be never less than 25 per cent. of the job rate, while 30 per cent. to 35 per cent. is fairer.