After an all-night study session the day before their last final exam, four first-year MBA students decide to stop for some much-needed coffee at the campus Starbucks. They arrive at 8:30am and are dismayed to find a rather long line. Fortunately for the students, a Starbucks executive happens to be in line directly in front of them. From her, they learn the following facts about this Starbucks location:
There are 3 employee types:
There is a single cashier who takes all orders, prepares non-beverage food items, grinds coffee, and purs drop coffee.
There is a single frozen drink maker who prepares blended and iced drinks.
There is a single espresso drink maker who prepares espressos, lattes, and steamed drinks.
There are typically four 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 iced drink customers order a drink that requires the use of a 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 Starbucks' many varieties of whole bean coffee and have it ground to their specifications at the store. This requires a total of 1 minute of the cashier's time (20 seconds to pour the coffee and 40 seconds to grind the whole bean coffee).
Customers arrive uniformly at the following rates from 7am when the store opens until 10am when the morning rush is over, with no customers arriving after 10am: Drip coffee = 25/hr, blended and iced drink = 20/hr, espresso = 70/hr, and ground coffee = 5/hr.
Each customer spends on average 30 seconds with the cashier to order and pay. About 25% of customers order food, which requires an additional 20 seconds of the cashier's time. While waiting in line, the students reflect on these facts and ask themselves:
a. What is the implied utilization of the frozen drink maker? (round to 2 decimal places)
b. Which resource has the highest implied utilization? (Enter either: Cashier, Frozen, or Espresso)
c. From their conversations with the executive, they learn that Starbucks is considering a promotion on scones, which will likely increase the percentage of customer ordering food to 30%. How will this affect the implied utilization of the cashier? (Answer this as the new utilization only, in percent, rounded to one decimal place, do not include % sign)