We have a six-stations production line in which each station has different number of machines (in parallel): Workstation 1 has 5 identical machines with an average processing time of 15 minutes Workstation 2 has 2 identical machines with an average processing time of 10 minutes Workstation 3 has 3 identical machines with an average processing time of 7.5 minutes Workstation 4 has 6 identical machines with an average processing time of 30 minutes Workstation 5 has 2 identical machines with an average processing time of 7.5 minutes Workstation 6 has a single machine with an average processing time of 4 minutes. A. [10 points] Calculate the critical WIP for this line. Explain its meaning for this line B. [10 points] If we would like to achieve a throughput that is 80% of the bottleneck rate, what would be the average WIP that is necessary in the practical worst case? Explain. C. The workers at Workstation 5 will be replaced by inexperienced slower workers. However, we do not want this change to decrease the capacity of the line. What is the slowest average processing time that is acceptable for the machines in Workstation 5? D. [10 points] Now assume that we have only four workers working at the production line. These workers need to be with each part when they are being processed at each machine. What would be the throughput capacity of the production line in this scenario? Explain.