Question

Process Diagram for a Toasted Sandwich At a local business school, a toasted sandwich process uses a conveyor-fed oven. Zeynep is the sole operator of the sandwich-making process. In the first step of the process, she spends 2 minutes putting various ingredients in the sandwich. Then she puts the sandwich on a conveyor belt and, over a period of 12 minutes, the conveyor moves the sandwich from the beginning of the oven to the end of the oven, fully toasting it. After the sandwich comes out of the oven, Zeynep spends 1 minute slicing the sandwich and putting it in a box. At most, five sandwiches can fit in the oven at once. The toasting time in the oven does not depend on the number of sandwiches in the oven.

Refer to the Process Diagram for a Toasted Sandwich. Suppose another employee is hired to do the slicing and boxing, and Zeynep now only loads the sandwiches with the right ingredients. What is the hourly capacity of this process with the additional employee?

A. 2.4 sandwiches/hour

B. 12 sandwiches/hour

C. 23 sandwiches/hour

D. 25 sandwiches/hour

E. None of the answers are correct.

Answer 1

Capacity per hour resource = (60 mins/hr) / (processing time per unit in minutes)

For oven the Capacity per hour resource = batch size x [(60 mins/hr) / (processing time per unit in minutes)]

Process Step	Resource	Processing time (minutes) per unit	Capacity Per hour
Load Ingredients	New Employee	2 minutes/unit	(60 min/hour) / (2 min/unit) = 30 units/hr
Oven Baking	Oven	12 minutes/unit	[(60 min/hour) / (12 min/unit)] x 5 units/batch = 5 x 5 = 25 units/hr
Slicing and boxing	Zeynep	1 minute/unit	(60 min/hour) / (1 min/unit) = 60 units/hr

The lowest capacity of the resource is 25 units per hour for the resource Oven.

Thus, the oven limits the capacity of the process.

Capacity of the process = 25 sandwiches per hour