Analyses of Shift Pattern Effect on Productivity at the Kaingaroa Central Processing Plant.
A mechanized central processing yard for merchandizing tree length material into logs provides the opportunity for higher levels of mechanization as well as the potential to increase value recovery. Located in the middle of a large contiguous plantation forest area in the central North Island of New Zealand, the Kaingaroa Processing Plant (KPP) processes over 1 million tonnes of Radiata Pine per year into 70 to 80 different log sorts. The plant is run 24 hours per day, 6 days per week. The stems enter the plant and are scanned for size and shape. Four crews work in 12 hours shifts to control grading and value recovery from the stems. To manage and optimize the process, a comprehensive data collection procedure captures all important data. This database was analyzed to determine the effect of time of day, as well as day of shift on both productivity and value recovery. This paper provides an overview of the KPP operation, discusses shift work implications and presents results from the shift analyses. Example results include a slight but significant increase in productivity in the night time shift compared to daytime, as well a slight but significant decline in value recovery with time into shift.