STANDAEDS 207
TABLE 8 (CONTINUED)
Time per Inch Cut
With grain 003
Across grain 005
Time per group of edges handled and machined together:
Handle and inspect pieces between cuts Oil
Inspect after final cut 006
Total time per group of edges 017
VAKIABLES
J . jy. . number of pieces
number machined together
Let L equal total number of inches cut with the grain
Let I equal total number of inches cut across the grain
- , „ , total number of edges to be machined
number of pieces machined together
Then time of main cycles for job in minutes equals •
.ISIN + .003L + .OOBl + .017E.
The average time in minutes for the elements was
determined by only three time-motion studies.
The number of pieces to be machined together was
set by the judgment of the foreman, taking care to
make the number large enough.
Standard times were calculated by the above formula
for a wide range of work and for oak, chestnut, poplar,
and birch, beside occasional other woods.
These times were put into effect as the basis of
standard time and bonus, and proved satisfactory with
the following exceptions:
As to one important article, it was necessary to
require only one to be machined at once instead of two,
as at first required;
Birch proved to be so much more difficult to work
than the other woods, that the elements based on
lengths of cuts had to be increased; and
On a few parts the operation of joining was found