4
Definitions and assumptions
Actual turnaround periods Will vary in the field. As the number of systems
served increases, the percentage of replaceable items required for stock is
reduced. (See Figure
3.)
Figure 3
Effect of turnaround on spares stock
“”
I
II
50
-
50
-
-
lo-Day turnaround
-
lo-Day turnaround
-----2-Day
turnaround
-----2-Day
turnaround
EE
$
40-
$
40-
N
O
.
In Field (Thousands)
N
O
.
In Field (Thousands)
Population range-Population range
is the quantity of each type of SL-1
switch in the area served by the depot.
Spare stock size-The
quantity of spares for a given stock item depends on
the sparing interval, stock confidence level, failure rate, turnaround time for
repair, and population range.
Spares planning 553-3001-l 53