This method differs from all others in the variation of reward earned.
It is extremely simple in calculation, as the worker gets 10 per cent. increase in wages for every 10 per cent. of time saved. He cannot save more than, say, 99 per cent. of the time on the job, because when 100 per cent. is saved it means that the job is done in no time at all.
Suppose the time allowed is 10 hours. If it be done in 5 hours, 50 per cent. of the time has been saved, and the worker gets 50 per cent. increase of wages for the 5 hours he has worked. If the job be done in over 10 hours, day wage, say 10d. per hour, is paid for all the time taken. If done in 9 hours, 11d. per hour is paid; if in 8 hours, 1s. per hour; if in 7 hours, 13d. per hour; and so on.
The efficiency is the standard time (time allowed) divided by the time taken. If a line be plotted of efficiencies and rates-paid, the line is not a straight one, as in other cases, but a curve as shown in the diagram.
Reward rises rapidly at first, but it gets less and less as efficiency increases, which is in direct opposition to reward principles.
The method has little to recommend it except the simplicity of reckoning the reward payment.
It will be seen that the employer cannot possibly overpay the worker, no matter what his efficiency.