In this manner the best method is found, and one that puts all workers on exactly the same basis, which is the essence of the system. It is not claimed that the time study is perfect and that the records obtained are absolutely exact. Even with the greatest care errors will creep in and the times will be incorrect. This especially is the case with hand work. Again, the skill of the worker increases very considerably, and he himself finds quicker methods of doing the work. All that is claimed for the time study method is that the dividing up of the operation into elements, and timing them as carefully as possible and eliminating all unnecessary movements, gives the nearest approach to perfection of rate setting yet discovered; there is a bed-rock character about it that is not found in any other system. The time thus obtained is considered to be the fastest time in which the operation can be done. Actually, it is not the fastest time for two reasons, one being that any time so obtained may be improved on when the worker becomes thoroughly used to the job, and the other being that a good _average_ worker is chosen for the time study, and therefore a first-class man can improve on the time obtained. But it is _considered_ to be the fastest time, and we will call it the "base time." It is quite evident that this cannot be reached regularly by every worker, and this is taken into consideration when determining the standard time. To obtain the standard time--namely, the time in which the work is _expected_ to be done--an allowance is made on the base time. This allowance depends on the nature of the work, greater allowances being made for jobs that necessitate a good deal of handling than for jobs that are nearly all cutting, because cutting is independent of the worker. (_b_) THE BASIS OF REWARD PAYMENT. This standard time is the basis of the Reward System, and is therefore the most important time. It is so fixed in relation to base time that every worker put on that work should be able to reach it. If he does so, he is said to have reached an efficiency of 100 per cent. A worker who reaches continuously 100 per cent. is a high efficiency man. This efficiency should always be reached by a worker who follows the instructions and works diligently. Reward begins, however, considerably before this point is reached, because it may be necessary for a worker to be on a job some time before he reaches a high efficiency. Again, sometimes one worker is naturally slower than another, and although his work is good he can reach 100 per cent. efficiency only by special effort. There would be little encouragement if reward did not begin until the worker had reached the 100 per cent. point. For these reasons, and as an incentive to every man to become as highly efficient as possible, reward begins when the worker reaches 75 per cent. efficiency.