A man told his supplier that he didn't want customers to wait longer than 20 seconds, on average, on the phone.

After the first week, 39 people were working a single eight-hour shift. During this time, calls came in about every 20 seconds with a standard deviation of 20 seconds. Each call took about 12 minutes to process with a standard deviation of 3 minutes.

Is this supply or demand constrained? Why?

What is the utilization of the current staff level?

What is the CVa and how do you solve for it?

How long does a customer have to wait after calling in?

What number of workers would be the best to optimize the process?