In the current scenario, the major bottlenecks in the system are the drying units for wet berries and the berry separation lines. While the drying units’ capacity can be increased by purchasing additional units, the throughput of the system will still be limited by the limitation of the separation lines. If the average rate of inflow of berries is 1500bbl/hr, then with the effective separation capacity of 1200bbl/hr, the plant will incur a backlog of 300bbl/hr.
If the shift start times stay as it is, and the processing divisions start four hours after the receiving division, the truckers toward the end of the day will have to wait, since the cumulative backlog caused by processing will exhaust the bin storage capacity. The wait times for the truckers can be reduced by converting some of the dry bins to wet bins. However, this measure will not completely eliminate the trucker wait times.
The best solution is to acquire one additional drying unit and advancing the processing shift from 11AM to 8AM. The backlog per hour of 300bbl/hr (due to the separation unit), will be manageable by the available storage capacity in the bins, even without converting the bins. The truckers will not have to wait to offload the berries. The accumulated backlog of berries can be processed in approximately 3.75 hours after the end of scheduled 12 working hours. With the new expected ratio of wet to dry berries (7:3), not adding an additional drying unit will require the plant to work 9 extra hours to eliminate the backlog. The cost benefit of adding the additional drying unit and advancing the shift start time are higher than the cost benefit of other options considered.
THE COMPANY
The Receiving Plant I (RPI) of National Cranberry Cooperative (NCC) processes both wet and dry cranberries in a highly mechanized process involving 400 workers during peak season. The processed berries are sold in bulk and bags.
PROBLEM STATEMENT
NCC is currently wrestling with both