UCP-FCEE Exercícios aulas práticas 2 (filas de espera)
Gestão de Operações, 2 semestre
1. The Bijou Theater in Hermosa Beach, California, shows vintage movies. Customers arrive at the theater line at the rate of 100 per hour. The ticket seller averages 30 seconds per customer. This includes placing validation stamps on customers’ parking lot receipts and punching their frequent watcher cards.
a. What is the average time a customer waits before he sits?
b. What would be the effect on the “sitting” time of having a second ticket taker doing nothing but the validations and card punching, thereby cutting the average service time to 20 seconds?
c. Would “sitting” time be less than in b) if a second window was opened with each server doing all the tasks?
2. After graduation from your MBA you were hired by the AiTiCuerni. Your first project is the sizing of a call center to business customers of Pessimus Company. Each call takes on average 4m and the call center receives a call every 30 seconds. The cost of each place, including the salary and equipment is €15 per hour.
a) If you wish that each customer don’t wait loner than 3 minutes, how many employees should you have at each moment (consider the usual distributions)? On average, how many customers are waiting to be served?
b) Now imagine that the VIP customers are only willing to wait one-minute (before they start penalizing the service quality). Given the importance of these customers the company is considering the following options:
a. Increase the number of employees in order to serve all customers in less than one minute, independently of its type.
b. Create a new phone number with exclusive employees and resources to VIP customers, around 20% of demand.
What is the best option? Justify with calculus and qualitatively your option.
c) Market research suggests that the exclusive service to VIP customers can arise additionally revenues, with the training of these employees as sellers. How much revenues would this additionally service have to raise on average on each call in order to pay all the implementation of this VIP service (against the base solution of 3 minutes waiting time per customer from 1.)?
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