Using  the   process   flow   map of the current process at Receiving Plant 1 (henceforth, RP1) in Figure 1 below, mark the capacity and implied utilization of each resource.1 Mark the maximum contents of the bin. Detail your calculations below.

Homework: National Cranberry Cooperative

 

 

 

 

General Assuptions:

 

• On a typical busy day there are 17,280 bbl arrive evenly over the 12-hr period (7am to 7pm). This is based on a typical busy day in
• The process is approximately a “continuous flow”
• Wet berries are 75% of all
• Holding bins 17-24 are dedicated to wet
• Assume that the capacity of each Kiwanee dumper is 600 bbl/hour (Why? It takes on average 8 minutes to dump a truck, and a truck holds on average 75 So, from Little’s Law, each dumper will take 600 bbl/hr).
• Cranberry processors (shown as boxes in the flow map) hold negligible amount of in- ventory compared to what bins and trucks (shown as triangles in the flow map) can
• Each separator line operates at its effective capacity (of 400 bbl/hour).
• Assume that 1 dechaffer is dedicated to dry berries and 2 dechaffers are dedicated to wet
• Assume each dryer’s capacity is 200 bbl/hour.
• Drivers are paid $100/hr. Rates for other employees are given in the
• The peak-period in the season lasts for 20
• Overtime is well-specified in the case as anytime beyond 11pm (until end of operations).

 

• Worker wages are $8/hour/worker. OT premium is 50%. During OT, NCC operates with nine OT
• The cost of an additional dryer is $60,000 (per dryer).

 

Question  1  (Process  Schematic  of  Receiving  Plant  1).  Using  the   process   flow   map of the current process at Receiving Plant 1 (henceforth, RP1) in Figure 1 below, mark the capacity and implied utilization of each resource.¹ Mark the maximum contents of the bin. Detail your calculations below.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

¹Recall: Implied Utilization is a KPI that compares the capacity with the demand rate.

 

 

Figure 1: Process Schematic

 

Question 2 (Maximum Throughput). On a busy day, what is RP1’s current maximum hourly throughput rate?

 

 

Figure 2: Inventory Buildup at NCC

 

Question 3 (Inventory Buildup at NCC).  Assuming  all  operations  at  RP1  start  at 7am (on a busy day), present the situation during such a day by constructing the inven- tory buildup diagram for bins and trucks. Mark the bin and truck inventory clearly.²

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

²You can use Excel instead of the figure below, but please make sure to attach the final plot from Excel.

 

Question 4 (Process Improvement  Measures).  What recommendations would you make to Mr. Schaeffer regarding the investment (cost vs. benefit) of

 

1.    an additional Kiwanee dumper?

 

 

 

 

2. an additional dryer?

 

 

 

 

 

Question 5 (Waiting Cost Analysis). Consider your inventory buildup diagram from Figure 2. What is the cost (in thousands of dollars) of total truck waiting time?³

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

³If T is the total number of hours of truck waiting time and R is the (wage) rate of a truck driver, then

T × R is the cost of truck waiting time.

 

Question 6 (Overtime Costs). What is the total overtime (henceforth, OT) in  hours? What is the total cost of OT over the peak period?⁴

 

Optional (Cost-Benefit  Analysis  of  the  Dryer).  What would happen if you add a 4^th dryer? What is the overtime savings? What is the truck waiting time savings? Is it still a good idea to add a 4^th dryer (given its cost)? Why or why not? How about a 5^th dryer?⁵

 

Optional (Cost-Benefit Analysis of Converting a Bin). How many “dry berry” bins would you recommend converting to store dry or wet berries?⁶