Subject: Operation Management 

Utilization Rate : Flow Rate(Capacity Used) / Capacity

2. Trojan Café is a small on-campus coffee shop that operates from 7am until 10am during the morning rush, with no customers arriving after 10am. The store is thinking of streamlining its operation, and it is interested in understanding how this will impact the customer waiting time. Below are the basic facts about Trojan Café.
There are 4 employees:
? There is a single cashier who takes all orders, grinds coffee, and pours coffee.
? There is a single food preparer who prepares non-beverage food items,
? There is a single frozen drink maker who prepares blended and ice drinks.
? There is a single espresso drink maker who prepares espressos, lattes, and steamed drinks.
There are 4 types of customers:
? Drip Coffee customers order only drip coffee. This requires 20 seconds of the cashier's time to pour the coffee.
? Blended and Ice Drink customers order a drink that requires the use of the blender. These drinks take on average 2 minutes of work of the frozen drink maker.
? Espresso Drink customers order a beverage that uses espresso and/or steamed milk. On average, these drinks require 1 minute of work of the espresso drink maker.
? Ground Coffee customers buy one of Trojan Café's many varieties of whole bean coffee and have it ground to their specification at the store. This requires a total of 1 minute of the cashier's time: 20 seconds to pour the coffee (bean), and another 40 seconds to grind the whole bean coffee.During 7am to 10am, the customers arrive uniformly at the following rates:

? Drip Coffee customers: 28 customers per hour
? Blended and Ice Drink customers: 20 customers per hour
? Espresso Drink customers: 56 customers per hour
? Ground Coffee customers: 6 customers per hour
Each customer spends, on average, 20 seconds with the cashier to order and pay. Approximately 25 percent of all customers order food, which require 20 seconds of the food preparer's time per transaction.
Answer the following questions:
a. What is the utilization of the Cashier?
b. What is the utilization of the Food Preparer?
c. What is the utilization of the Frozen Drink Maker?
d. What is the utilization of the Espresso Drink Maker?
e. Who is the bottleneck?
To streamline the operations and reduce costs, a financial consultant proposes that Trojan Café eliminates the Food Preparer position, and have the Cashier takes over the food preparation activity.
f. Under this proposal, who will be the bottleneck?
g. How will this proposal affect the customer's waiting time?