Managing Business Process Flows
Principles of Operations Management
Kristen's Cookie Case
Start with a Process Flow Diagram:
1.) How long will it take to fill a Rush Order?
To find this out I took the entire Process Throughput Time as:
a. Mix and Spoon = 6 + 2 = 8 minutes
b. Load and Bake = 1 + 9 = 10 minutes
c. Remove and Cool = 5 minutes
d. Pack and Collect Payment = 1 + 2 = 3 minutes
If the rush order is for only 1 dozen it will take 26 minutes minimum to fill the order.
2.) How many orders can you fill in a night, assuming you are open for 4 hours each night?
After the 1st batch which takes 26 minutes Kristen and her associate can bake a dozen every 10 minutes. If open for 4 hours they can back 6 dozen every 4 hours for a total of 24 dozen.
3.) How many of your own and your roommate's valuable time will it take to fill each order?
For Kristen we have:
Process Activity Cycle Time
Wash Bowl & Mix 6 minutes
Fill Tray 2 minutes
Total 8 minutes
For Roommate we have:
Process Activity Cycle Time
Prepare Oven 1 minute
Remove 0 minutes
Pack, Collect Money 3 minutes
Total 4 minutes
4.) Because your baking trays can hold exactly one dozen cookies, you will produce and sell cookies by the dozen. Should you give any discount for people who order two dozen cookies, three dozen cookies, or more? If so, how much? Will it take any longer to fill a two-dozen cookie order than a one-dozen cookie order?
Kristen's cost for her ingredients are in effect fixed. The only variable cost is labor which can vary with the size of the batch of cookies made. We can use a range of batches to come up with an estimate.
This table breaks down the activities and overall cycle times
1 Dozen
Process Activity Labor Resource Cycle Time Starting Time Finish Time
Order Entry Internet 0 mins 00:00 00:00
Wash Bowl, Mix Kristen 6 mins 00:00 06:00
Fill Tray Kristen 2 mins 06:00 08:00
Prepare Oven Roommate 1 mins 08:00 09:00...