Case Study:
Sima Donuts supplies its retail outlets with the ingredients for making fresh donuts. A central warehouse from which trucks are dispatched is located in Atlanta. Trucks leave Atlanta warehouse early morning to make pallet-load deliveries to the Florida market and may return at any time. The trucks may also pick up empty containers and supplies from vendors in the general area. The Atlanta warehouse is located at X= 2084, Y= 7260. The total time on a route may be 40 hours including breaking times and total route distance may be up to 1,400 miles. Team drivers are used so that no overnight breaks are required, but two-hour rest breaks are allowed each day. Average driving speed is taken to be 45 miles per hour. Additional data about the stops are as follows
|
No.
|
Stop location
|
Stop Type
|
Volume, pallets
|
X-coordinate
|
Y-coordinate
|
Loading/Unloading Time (Mins.)
|
|
|
|
1
|
Tampa, FL
|
Delivery
|
20
|
1147
|
8197
|
15
|
|
|
2
|
Clearwater, FL
|
Pickup
|
14
|
1206
|
8203
|
45
|
|
|
3
|
Daytona Beach, FL
|
Delivery
|
18
|
1052
|
7791
|
45
|
|
|
4
|
Fort Lauderdale, FL
|
Delivery
|
3
|
557
|
8282
|
45
|
|
|
5
|
North Miami, FL
|
Delivery
|
5
|
527
|
8341
|
45
|
|
|
6
|
Oakland Park, FL
|
Pickup
|
4
|
565
|
8273
|
45
|
|
|
7
|
Orlando, FL
|
Delivery
|
3
|
1031
|
7954
|
45
|
|
|
8
|
St Petersburg, FL
|
Pickup
|
3
|
1159
|
8224
|
45
|
|
|
9
|
Tallahassee, FL
|
Delivery
|
3
|
1716
|
7877
|
45
|
|
|
10
|
West Palm Beach, FL
|
Delivery
|
3
|
607
|
8166
|
45
|
|
|
11
|
Miami-Puerto Rice
|
Delivery
|
4
|
527
|
8351
|
45
|
|
There are three trucks: 20-pallet capacity truck, 25-pallet capacity truck, and 30-pallet capacity truck. Design the routes for this set of deliveries and pickups. Which trucks are to be assigned to which routes? What is the dispatch plan? Since delivery and pickup stops are allowed on the same route, make sure that pickups at any point don't exceed the leftover capacity in the vehicle. For instance, the following route is feasible using a 20-pallet capacity truck. However, you still need to check for total time on route and total route distance.
|
Route
|
Quantity
|
|
Depot
|
|
|
Tampa
|
Deliver 20 pallets
|
|
Clearwater
|
Pickup 14 pallets
|
|
Depot
|
|
Use savings methods to be obtain an initial routing plan based on distance. The plan will most likely be infeasible when you consider timings, hence be creative by adjusting your solution from savings method to obtain a very good feasible solution.
What do you need to submit?
a. Distance, time and savings matrices. Also, descending ordering of saving matrix.
b. Routing Plan using Savings Method and show where solution is infeasible.
c. Improved routing plan which satisfies distance and time constraints.