The writer has found that when some jobs are divided into their proper
elements, certain of these elementary operations are so very small in
time that it is difficult, if not impossible, to obtain accurate
readings on the watch. In such cases, where the work consists of
recurring cycles of elementary operations, that is, where a series of
elementary operations is repeated over and over again, it is possible to
take sets of observations on two or more of the successive elementary
operations which occur in regular order, and from the times thus
obtained to calculate the time of each element. An example of this is
the work of loading pig iron on to bogies. The elementary operations or
elements consist of:
(a) Picking up a pig.
(b) Walking with it to the bogie.
(c) Throwing or placing it on the bogie.
(d) Returning to the pile of pigs.
Here the length of time occupied in picking up the pig and throwing or
placing it on the bogie is so small as to be difficult to time, but
observations may be taken successively on the elements in sets of three.
We may, in other words, take one set of observations upon the combined
time of the three elements numbered 1, 2, 3; another set upon elements
2, 3, 4; another set upon elements, 3, 4, 1, and still another upon the
set 4,1, 2. By algebraic equations we may solve the values of each of
the separate elements.
If we take a cycle consisting of five (5) elementary operations, a, b,
c, d, e, and let observations be taken on three of them at a time, we
have the equations:
[Transcriber's Note: omitted]
The writer was surprised to find, however, that while in some cases
these equations were readily solved, in others they were impossible of
solution. My friend, Mr. Carl G. Barth, when the matter was referred to
him, soon developed the fact that the number of elements of a cycle
which may be observed together is subject to a mathematical law, which
is expressed by him as follows:
The number of successive elements observed together must be prime to the
total number of elements in the cycle.
Namely, the number of elements in any set must contain no factors; that
is, must be divisible by no numbers which are contained in the total
number of elements. The following table is, therefore, calculated by Mr.
Barth showing how many operations may be observed together in various
cases. The last column gives the number of observations in a set which
will lead to the determination of the results with the minimum of labor.
[Transcriber's note -- Table omitted]
When time study is undertaken in a systematic way, it becomes possible
to do greater justice in many ways both to employers and workmen than
has been done in the past. For example, we all know that the first time
that even a skilled workman does a job it takes him a longer time than
is required after he is familiar with his work, and used to a particular
sequence of operations. The practiced time student can not only figure
out the time in which a piece of work should be done by a good man,
after he has become familiar with this particular job through practice,
but he should also be able to state how much more time would be required
to do the same job when a good man goes at it for the first time; and
this knowledge would make it possible to assign one time limit and price
for new work, and a smaller time and price for the same job after being
repeated, which is much more fair and just to both parties than the
usual fixed price.
As the writer has said several times, the difference between the best
speed of a first-class man and the actual speed of the average man is
very great. One of the most difficult pieces of work which must be faced
by the man who is to set the daily tasks is to decide just how hard it
is wise for him to make the task. Shall it be fixed for a first-class
man, and if not, then at what point between the first-class and the
average? One fact is clear, it should always be well above the
performance of the average man, since men will invariably do better if a
bonus is offered them than they have done without this incentive. The
writer has, in almost all cases, solved this part of the problem by
fixing a task which required a first-class man to do his best, and then
offering a good round premium. When this high standard is set it takes
longer to raise the men up to it. But it is surprising after all how
rapidly they develop.
The precise point between the average and the first-class, which is
selected for the task, should depend largely upon the labor market in
which the works is situated. If the works were in a fine labor market,
such, for instance, as that of Philadelphia, there is no question that
the highest standard should be aimed at. If, on the other hand, the shop
required a good deal of skilled labor, and was situated in a small
country town, it might be wise to aim rather lower. There is a great
difference in the labor markets of even some of the adjoining states in
this country, and in one instance, in which the writer was aiming at a
high standard in organizing a works, he found it necessary to import
almost all of his men from a neighboring state before meeting with
success.
Whether the bonus is given only when the work is done in the quickest
time or at some point between this and the average time, in all cases
the instruction card should state the best time in which the work can be
done by a first-class man. There will then be no suspicion on the part
of the men when a longer "bonus time" is allowed that the time student
does not really know the possibilities of the case. For example, the
instruction card might read: