Susan's Sub Shop makes customer submarine sandwiches to order. There are 4 workers. The general flow of the process is:

[Stage A] Alex takes orders. It takes her 2 minutes to take an order.
[Stage B] Brittany slides the bun and adds meat/cheese. It takes 4 minutes per order .
[Stage C] Chelan adds toppings and condiments. It takes 5 minutes per order .
[Stage D] Dale bags the order. It takes 1 minute .

Susan wants to figure out the following:

a) What is the current maximum output of Susan's Sub Shop in number of units per hour?
b) Which stage is the bottleneck?
c) If we add another person, to which stage would we assign her?
d) After we assign another per son to the stage you answered in part c, what is the capacity of Susan's Sub Shop? Which stage is the new bottleneck? Assume it takes the new person the same amount of time as the existing person.
e) Hiring a new person turns out to be very expensive, so Susan decided not to hire her. Instead, Susan decided to cross-train all the 4 current workers. After cross training, each worker can work on all the 4 stages. What is the capacity of Susan's Sub Shop?