Consider a CONWIP flow line with 3 stations in series (1 ? 2 ? 3); each station consists of a set of identical machines. The unit processing times at stations 4.7 hours, 1.4 hours, and 3.1 hours, respectively.
There are 24 working hours in a day, and 5 working days per week. Currently there is a single machine at each station and the current demand is 3 units per day. Demand is expected to grow in the future and then stabilize; peak demand will be 13 units per day.
Answer the following questions using the data specified.
a.Calculate the bottleneck rate, the raw process time, and the critical WIP for this line. [Round the critical WIP up to the closest integer.]
b. If WIP is managed so that it averages w = 4 units (this is the CONWIP level), compute the best case, worst case, and practical worst case throughput and the corresponding cycle times for the line. You should be able to fill six values into the following table:
Best Worst PWC
TH
CT
c. How much work-in-process inventory, w, is needed to make the practical worst case throughput for this line equal to 90% of the maximum possible throughput?
d.Based purely on utilization calculations (and maintaining utilization < 100%), how many machines will be needed at each station to meet the peak demand? If WIP is managed so that it averages w = 15 units (this is the CONWIP level), compute the practical worst case cycle time for the line under peak demand, with your chosen of number of machines at each station.