In: Operations Management
You are the distribution manager for PROP CHICKENZ, a company that produces and distributes rubber
chickens. The transportation costs between warehouses and customers are shown in the matrix below:
Customer 1 |
Customer 2 |
Customer 3 |
Customer 4 |
|
Warehouse A |
8 |
8 |
11 |
5 |
Warehouse B |
10 |
7 |
15 |
7 |
Set up the transportation problem for each situation independently.
A- Each warehouse has a supply of 26 and each customer has a demand of 13. Demand must be satisfied. The objective is to minimize total shipping cost.
B- All demands are 23 and all supplies are 56. All demands must be met, but not all supplies must be shipped. The objective is to minimize total shipping cost.B-
C- All demands are 23 and all supplies are 36. All demands need not be met but ship as much as possible. The objective is to minimize total shipping cost.
D- All demands are 28 and all supplies are 46. All demands need not be met but each customer must receive at least 5 units. Ship as much as possible. The objective is to minimize total shipping cost.
First we set up the LP for the problem:
The boxes in green, are decision variables
The boxes in blue are constrains
The boxes in orange is the objective function
The formulae used:
Customer 1 | Customer 2 | Customer 3 | Customer 4 | |||||
Warehouse A | 8 | 8 | 11 | 5 | ||||
Warehouse B | 10 | 7 | 15 | 7 | ||||
Dec Var | How much to send from each WH to each customer | Customer 1 | Customer 2 | Customer 3 | Customer 4 | |||
Warehouse A | 7 | 0 | 13 | 6 | =SUM(C7:F7) | <= | 26 | |
Warehouse B | 6 | 13 | 0 | 7 | =SUM(C8:F8) | <= | 26 | |
=SUM(C7:C8) | =SUM(D7:D8) | =SUM(E7:E8) | =SUM(F7:F8) | |||||
>= | >= | >= | >= | |||||
13 | 13 | 13 | 13 | |||||
Objective function | ||||||||
Total shipping cost | =SUMPRODUCT(C3:F4,C7:F8) | |||||||
Minimization |
The solution:
Customer 1 | Customer 2 | Customer 3 | Customer 4 | |||||
Warehouse A | 8 | 8 | 11 | 5 | ||||
Warehouse B | 10 | 7 | 15 | 7 | ||||
Dec Var | How much to send from each WH to each customer | Customer 1 | Customer 2 | Customer 3 | Customer 4 | |||
Warehouse A | 7 | 0 | 13 | 6 | 26 | <= | 26 | |
Warehouse B | 6 | 13 | 0 | 7 | 26 | <= | 26 | |
13 | 13 | 13 | 13 | |||||
>= | >= | >= | >= | |||||
13 | 13 | 13 | 13 | |||||
Objective function | ||||||||
Total shipping cost | 429 | |||||||
Minimization |
A.
So for A:
Customer 1 | Customer 2 | Customer 3 | Customer 4 | |||||
Warehouse A | 8 | 8 | 11 | 5 | ||||
Warehouse B | 10 | 7 | 15 | 7 | ||||
Dec Var | How much to send from each WH to each customer | Customer 1 | Customer 2 | Customer 3 | Customer 4 | |||
Warehouse A | 7 | 0 | 13 | 6 | 26 | <= | 26 | |
Warehouse B | 6 | 13 | 0 | 7 | 26 | <= | 26 | |
13 | 13 | 13 | 13 | |||||
>= | >= | >= | >= | |||||
13 | 13 | 13 | 13 | |||||
Objective function | ||||||||
Total shipping cost | 429 | |||||||
Minimization |