The operations manager of a soon-to-open branch of a large bank is in the process of configuring…
The operations manager of a soon-to-open branch of a large bank is in the process of configuring teller operations and wants to minimize complaints during the busy noon hour.
The manager has obtained anticipated arrival times for the new branch. An average of 80 customers are expected to arrive during the noon hour (arrival is Poisson). The average service time to process a single transaction is 90 seconds while the average service time for customers with multiple requests is four minutes. 60% of all customers are expected to have multiple requests. All service times are assumed negative exponential.
The plan is to have 5 tellers available. Under consideration are the following options
- One queue serving all customers first-in, first out. Next person in the front of the line goes to the next available teller.
- Have two waiting lines: one teller for customers with a single transaction and four tellers to service customers with multiple transactions.
If you were the manager, which option would you choose and why? Support your conclusion using the characteristics and customer experiences in each system (calculate the length of the queues, average time waiting in queues, and the maximum length of the queues for a 97% probability) and any other measure you deem appropriate. Note the assumptions you used in your analysis.