FINDINGS OF THE COMMITTEE 29
a matter of fact, it may be conjectured that in any industrial group
both conditions would be present at one time or another during the
period. } }
The distinction between industrial productivity and industrial
efficiency should be kept in mind, since the terms are not synonymous.
Productivity relates to the output of the machine or plant in a given
time without respect to the input of material, labor, power or man-
agerial effort; efficiency seeks to express the relation of output to
input. In the case of a simple mechanism, efficiency may readily be
measured and expressed, but in the case of an industrial plant, where
the factors of input are expressed in wholly different units which
cannot precisely be evaluated or reduced to a common denominator
for purposes of summation, efficiency cannot be computed mathe-
matically; in fact, we know of no established formula which could
be applied to express accurately industrial plant efficiency. Even if
such a formula existed, it is highly improbable that, in an extensive
assay such as this, information could be obtained from the field which
would reasonably permit its use,
The thesis which is under consideration, it is true, has to do with
to a third factor—executive control. Since information on efficiency
per se could not be obtained, the best substitute appeared to be that
factor which most accurately reflected the effect of changes in effici-
ency. Production rate on the basis of man-hours worked was selected,
not only for the latter reason, but because it was directly comparable
with the accident frequency and severity rates.
Although increased productivity in a given plant might be secured
at the expense of over-all efficiency and also of safety (just as a steam
boiler may be forced above its rated capacity at the expense of efficiency
and, ultimately, of safety) —and, inversely, decreased productivity
might not be indicative of decreased efficiency—it was felt that in-
creasing productivity in a large industrial group would almost cer-
tainly indicate the existence of an increasing industrial efficiency.
Then if it could be shown that a preponderant proportion of cases
showed either increased production rates accompanied by decreased
accident rates, or decreased production rates accompanied by increased
accident rates, the existence of a high degree of correlation would be
indicated.
Table 1-A to 1-H show the general behavior of the rates of the vari-
ous industrial groups from which satisfactory data were collected.
The totals of these eight tables may be combined according to the
nature of the implied correlation as follows:
