| | | | | | | | +-------------+ 12.70 +-------+ 13.55 +-------+ 13.30 +-------+ | | | | | | | | | +-------+ +-------+ +-------+ +------ |Total (mins.)| 12.70 | | 13.55 | | 13.30 | | 13.18 ---+-------------+-------+-------+-------+-------+-------+-------+------ It will be seen that the watch is not stopped until the end of the complete operation, and therefore the last reading indicates how long the operation has taken; it is the sum of all the elements. If anything happens which is not a part of the operation--for instance, if a tool needs replacing owing to accident or becoming dull too quickly, or if a belt breaks--the watch is stopped, and when the operation begins again it is started and goes on from the point where it stopped. During the timing, observations are made to determine whether any part of the operation may be done in a quicker or easier way, or whether any element is taking longer than it ought to do. It must be particularly noted that there is a distinct difference between time study and time recording. Any job, the slowest or fastest in the whole factory, may be time-recorded by merely observing the time with a stop-watch, but this is not a time _study_. When several sets of figures have been obtained, the number of sets depending on the circumstances, the timing part of the study is over. The figures are now examined. The time of each element is obtained as described in the example. In noticing the times of any one element, times which are much less or much greater than the others are eliminated, and the average of the remaining times is taken. Then all these averages are added together, and the average time of the complete operation is thus obtained. This time is considered to be the fastest time in which the operation can be done. It is not actually the fastest for two reasons. One is that any time so obtained may be improved on when the worker becomes thoroughly used to the job, and the other is that a good _average_ worker is chosen for the time study; 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. Now, this time has been obtained under exceptional circumstances. When a man is working on a time study job--that is, with the knowledge that he is on trial, so to speak, and with the time study engineer timing and observing every detail and motion--he works faster than usual. There is no opportunity for little breaks, or rests, or breathing spaces; it is hard slogging all the time. The time study engineer does not intend it to be so, but by the nature of the circumstances that is what happens, and no man can keep this up for long.