Kristens Cookie Company

Question 1

Rush order takes the least possible time for preparing the dozen of cookies. The following is a detailed summary of time used to prepare the rush order:

Activity Time

Wash the bowl, add and mix ingredients 6 minutes

Dish up the tray (1 dozen) 2 minutes

Put the cookies in the oven, start timer 1 minute

Bake the cookies 9 minutes

Remove the tray from the oven* 0 minute

Let the cookies cool 5 minutes

Pack the cookies 2 minutes

Accept payment 1 minute

Total time: 26 minutes

*- further the removing step will be ignored because it does not take any additional time

It will take 26 minutes to fill the rush order.

Question 2

Activity Output

Wash the bowl, add and mix ingredients 4 hours*60 minutes/6 minutes=40 dozens

Dish up the tray (1 dozen) 4*60/2=120 dozens

Put the cookies in the oven, start timer 4*60/1=240 dozens

Bake the cookies 4*60/9=26.6 dozens~26 dozens

Let the cookies cool 4*60/5= 48 dozens

Pack the cookies 4*60/2= 120 dozens

Accept payment 4*60/1= 240 dozens

The maximum output if determined by the output of a slowest activity. Baking the cookies is the slowest activity performed by Kristen and her roommate. Therefore, the maximum orders they can fill in a night is 26 dozens, based on production capabilities.

This graph shows that for preparing 1 dozen of cookies Kristen needs 26 minutes. However, in order to prepare 2 dozens of cookies she does not need 52 minutes because no matter how many dozens she need to cook (1, 2 or 3) she will spend 6 minutes or mixing the ingredients.

The following diagram depicts the process:

To sell 3 dozens of cookies girls will need 46 minutes.

The sequence of finishing time for every dozen is 26, 36, 46, 56, 66, 76, 86.....236.

The maximum number of orders they can fill a night is 22 orders.

Question 3

For one dozen of cookies

Activity Kristen per dozen Roommate per dozen

Wash the bowl, add and mix ingredients 6 minutes X

Dish up the tray (1 dozen) 2 minutes X

Put the cookies in the oven, start timer X 1 minute

Bake the cookies X X

Let the cookies cool X X

Pack the cookies X 2 minutes

Accept payment X 1 minute

Total: 8 minutes 4 minutes

For two dozen of cookies

Activity Kristen per dozen Roommate per dozen

Wash the bowl, add and mix ingredients 6 minutes X

Dish up the tray (1 dozen) 4 minutes X

Put the cookies in the oven, start timer X 2 minutes

Bake the cookies X X

Let the cookies cool X X

Pack the cookies X 4 minutes

Accept payment X 2 minutes (1 minute)*

Total: 10 minutes 8 minutes (7 minutes)*

*-assuming that one customer orders 2 dozens

For two dozen of cookies

Activity Kristen per dozen Roommate per dozen

Wash the bowl, add and mix ingredients 6 minutes X

Dish up the tray (1 dozen) 6 minutes X

Put the cookies in the oven, start timer X 3 minutes

Bake the cookies X X

Let the cookies cool X X

Pack the cookies X 6 minutes

Accept payment X 3 minutes (1 minute)*

Total: 12

...