SECTION 3
ACCIDENTS IN TERMS OF PRODUCTION
THE basis upon which the accident frequency and severity rates have
been calculated elsewhere in this report is the man-hours worked.
Such rates are usually accepted as the most satisfactory measures of
general hazards and furnish the best guide for accident-prevention
efforts. Another basis upon which accident rates may be calculated
is the quantity of production. There are some instances where acci-
dent rates in terms of production may be used to advantage as an
adjunct to rates in terms of man-hours.
The accident frequency and severity rates have been determined in
terms of production for 24 industrial groups. The trends for each
group are shown in the accompanying Charts 40 to 63, inclusive.
By the least-square method the increases or decreases for each rate
have been calculated. These percentages appear in Table III. The
accident frequency and severity rates when expressed in terms of
production have, with a few exceptions, decreased during the period
considered. In considering accident rates in terms of production, it is
essential to bear in mind that those of different industrial groups can-
not be combined. Furthermore, the rates are influenced by any one
of the following conditions: reduced number of accidents during a
period when the quantity of production remained stationary; the
aumber of accidents stationary during a period when the quantity
of production increased; the number of accidents reduced during a
period when the quantity of production increased; and the number of
accidents reduced at a more rapid rate than the quantity of produc-
tion decreased.
All other things being equal, greatest reduction in accident rates,
expressed in terms of production, will take place when the number
of accidents is decreased simultaneously with an increase in the quan-
tity of production. Accident frequency and severity rates in terms
of production were derived for 25 industrial groups; the per cent
of increase or decrease of each rate was determined by the least-square
method for the period involved in each instance. The basic data
and the’ results of the computations are shown in Table III. In the
majority of the groups of Table III an increase in the quantity of
production occurred simultaneously with a decrease in the number of
accidents, therefore two favorable conditions obtained which resulted
in large reductions in accident frequency and severity rates when ex-
pressed in terms of production. Such favorable conditions prevailed
in the industries listed on page 84.
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