Transportation Problem

North West Corner Rule

Example 2

Luminous lamps has three factories - F1, F2, and F3 with production capacity 30, 50, and 20 units per week respectively. These units are to be shipped to four warehouses W1, W2, W3, and W4 with requirement of 20, 40, 30, and 10 units per week respectively. The transportation costs (in Rs.) per unit between factories and warehouses are given below.

Factory
Warehouse Supply
W1 W2 W3 W4
F1 1 2 1 4 30
F2 3 3 2 1 50
F3 4 2 5 9 20
Demand 20 40 30 10  

Find an initial basic feasible solution of the given transportation problem

Solution.

Starting from the North west corner, we allocate 20 units to F1W1. The demand for the first column is completely satisfied.

Table 1

Factory
Warehouse Supply
W1 W2 W3 W4
F1 2 1 4  30 10
F2 3 3 2 1 50
F3 4 2 5 9 20
Demand 20 40 30 10  

Proceeding in this way, we observe that F1W2 = 10, F2W2 = 30, F2W3 = 20, F3W3 = 10, F3W4 = 10. An initial basic feasible solution is exhibited below.

Final Table

Factory
Warehouse Supply
W1 W2 W3 W4
F1 1 4 30
F2 3 1 50
F3 4 2 20
Demand 20 40 30 10  

Number of basic variables = m + n – 1 = 3 + 4 – 1 = 6.

Initial basic feasible solution

20 X 1 + 10 X 2 + 30 X 3 + 20 X 2 + 10 X 5 + 10 X 9 = 310.

 


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