Answer:
The BHFC
The BHFC should add the second window as it will half customer's waiting time and increase revenue for the branch.
Explanation:
a) Data and Calculations:
Customers arrival rate at the window = 12/hour
equivalent to 12/60 minutes or 1/5 minutes
Time the teller takes to serve a customer = 4 minutes
Total time to serve 12 customers in an hour = 48 minutes
Cost of adding a second window to the branch = $20,000
Savings in reducing customer waiting time = $2,000
Average customer waiting time = 4 minutes
Total time to serve 12 customers in an hour using the second window = 24 minutes (48/2)
Therefore, customers waiting time will half to 2 minutes (4/2)
Increase in revenue by the reduction in customer waiting time = $2,000 * 24 = $48,000
Net saving = $28,000 ($48,000 - $20,000)