Rockwell Automation Arena Packaging Users Guide - Manual (Page 62)

A RENA P ACKAGING T EMPLATE U SER ’ S G UIDE
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The value of this statistic is the time-weighted average of the conveyor variable Conveyor
Name_GoodOutputRate over the time the conveyor had a speed factor greater than zero.
Average Supply Time—This statistic reports the average time the conveyor could supply
units to the downstream process if the upstream process stopped. Only time that the
conveyor was running (i.e., had a speed factor greater than zero) is considered. This
statistic is calculated as follows:
Average Supply Time = (Average Units Traveling + Average Units Accumulated)/Average
Good Output Rate
Average Buffer Time—This statistic reports the average time the conveyor could accept
units from the upstream process if the downstream process stopped. Only time that the
conveyor was running (i.e., had a speed factor greater than zero) is considered. This
statistic is calculated as follows:
Average Buffer Time = (Capacity - Average Units Traveling - Average Units Accumulated)
/Average Input Rate
where
Capacity is the capacity of the conveyor in units.
Average Speed Factor Greater Than 0—This statistic reports the average speed factor of
the conveyor when the conveyor was running (i.e., had a speed factor greater than zero).
The average speed factor is equivalent to the average run speed of the conveyor divided
by its nominal run speed.
The value of this statistic is the time-weighted average of the conveyor variable Conveyor
Name_SpeedFactor over the time the conveyor had a speed factor greater than zero.
Yield—This statistic reports the efficiency of the conveyor for transferring good product.
This statistic is calculated as follows:
Yield = ((Total Good Units Conveyed)/(Total Units Conveyed)) * 100
Performance Index (PI)—This statistic reports an overall rating for the conveyor. Under
ideal conditions, the PI value is greater than or equal to 100. This statistic is calculated as
follows:
PI = ((Yield) * (Utilization) * (Average Speed Factor))/100
Therefore, a PI of “100” means that the accumulating conveyor had no loss and was
always running at its nominal run speed during its scheduled time. Normally, the PI for a
conveyor will be less than 100. Locating and eliminating the source of low PI can improve
productivity.