2. Example-2
Find Solution using Russell's Approximation method
| D1 | D2 | D3 | D4 | Supply | S1 | 11 | 13 | 17 | 14 | 250 | S2 | 16 | 18 | 14 | 10 | 300 | S3 | 21 | 24 | 13 | 10 | 400 | Demand | 200 | 225 | 275 | 250 | |
Solution: TOTAL number of supply constraints : 3 TOTAL number of demand constraints : 4 Problem Table is
| `D_1` | `D_2` | `D_3` | `D_4` | | Supply | `S_1` | 11 | 13 | 17 | 14 | | 250 | `S_2` | 16 | 18 | 14 | 10 | | 300 | `S_3` | 21 | 24 | 13 | 10 | | 400 | | Demand | 200 | 225 | 275 | 250 | | |
Table-1: Calculate `bar U_i` and `bar V_j` (where `bar U_i` is the largest cost in row and `bar V_j` is the largest cost in column)
| `D_1` | `D_2` | `D_3` | `D_4` | | Supply | `bar U_i` | `S_1` | 11 | 13 | 17 | 14 | | 250 | `17` | `S_2` | 16 | 18 | 14 | 10 | | 300 | `18` | `S_3` | 21 | 24 | 13 | 10 | | 400 | `24` | | Demand | 200 | 225 | 275 | 250 | | | | `bar V_j` | `21` | `24` | `17` | `14` | | | |
2. Compute reduced cost of each cell `Delta_(ij)`, where `Delta_(ij) = c_(ij) - (bar U_i + bar V_j)`
`1. Delta_11 = c_11 - (bar U_1 + bar V_1) = 11 - (17 +21) = color{blue}{-27} `
`2. Delta_12 = c_12 - (bar U_1 + bar V_2) = 13 - (17 +24) = color{blue}{-28} `
`3. Delta_13 = c_13 - (bar U_1 + bar V_3) = 17 - (17 +17) = color{blue}{-17} `
`4. Delta_14 = c_14 - (bar U_1 + bar V_4) = 14 - (17 +14) = color{blue}{-17} `
`5. Delta_21 = c_21 - (bar U_2 + bar V_1) = 16 - (18 +21) = color{blue}{-23} `
`6. Delta_22 = c_22 - (bar U_2 + bar V_2) = 18 - (18 +24) = color{blue}{-24} `
`7. Delta_23 = c_23 - (bar U_2 + bar V_3) = 14 - (18 +17) = color{blue}{-21} `
`8. Delta_24 = c_24 - (bar U_2 + bar V_4) = 10 - (18 +14) = color{blue}{-22} `
`9. Delta_31 = c_31 - (bar U_3 + bar V_1) = 21 - (24 +21) = color{blue}{-24} `
`10. Delta_32 = c_32 - (bar U_3 + bar V_2) = 24 - (24 +24) = color{blue}{-24} `
`11. Delta_33 = c_33 - (bar U_3 + bar V_3) = 13 - (24 +17) = color{blue}{-28} `
`12. Delta_34 = c_34 - (bar U_3 + bar V_4) = 10 - (24 +14) = color{blue}{-28} `
| `D_1` | `D_2` | `D_3` | `D_4` | | Supply | `bar U_i` | `S_1` | 11 [-27] | 13 [-28] | 17 [-17] | 14 [-17] | | 250 | `17` | `S_2` | 16 [-23] | 18 [-24] | 14 [-21] | 10 [-22] | | 300 | `18` | `S_3` | 21 [-24] | 24 [-24] | 13 [-28] | 10 [-28] | | 400 | `24` | | Demand | 200 | 225 | 275 | 250 | | | | `bar V_j` | `21` | `24` | `17` | `14` | | | |
The most negative `Delta_(ij)` is -28 in cell `S_3 D_4`
The allocation to this cell is min(400,250) = 250. This satisfies the entire demand of `D_4` and leaves 400 - 250 = 150 units with `S_3`
Table-1: This leads to the following table
| `D_1` | `D_2` | `D_3` | `D_4` | | Supply | `S_1` | 11 | 13 | 17 | 14 | | 250 | `S_2` | 16 | 18 | 14 | 10 | | 300 | `S_3` | 21 | 24 | 13 | 10 (250) | | 150 | | Demand | 200 | 225 | 275 | 0 | | |
Table-2: Calculate `bar U_i` and `bar V_j` (where `bar U_i` is the largest cost in row and `bar V_j` is the largest cost in column)
| `D_1` | `D_2` | `D_3` | `D_4` | | Supply | `bar U_i` | `S_1` | 11 | 13 | 17 | 14 | | 250 | `17` | `S_2` | 16 | 18 | 14 | 10 | | 300 | `18` | `S_3` | 21 | 24 | 13 | 10(250) | | 150 | `24` | | Demand | 200 | 225 | 275 | 0 | | | | `bar V_j` | `21` | `24` | `17` | -- | | | |
2. Compute reduced cost of each cell `Delta_(ij)`, where `Delta_(ij) = c_(ij) - (bar U_i + bar V_j)`
`1. Delta_11 = c_11 - (bar U_1 + bar V_1) = 11 - (17 +21) = color{blue}{-27} `
`2. Delta_12 = c_12 - (bar U_1 + bar V_2) = 13 - (17 +24) = color{blue}{-28} `
`3. Delta_13 = c_13 - (bar U_1 + bar V_3) = 17 - (17 +17) = color{blue}{-17} `
`4. Delta_21 = c_21 - (bar U_2 + bar V_1) = 16 - (18 +21) = color{blue}{-23} `
`5. Delta_22 = c_22 - (bar U_2 + bar V_2) = 18 - (18 +24) = color{blue}{-24} `
`6. Delta_23 = c_23 - (bar U_2 + bar V_3) = 14 - (18 +17) = color{blue}{-21} `
`7. Delta_31 = c_31 - (bar U_3 + bar V_1) = 21 - (24 +21) = color{blue}{-24} `
`8. Delta_32 = c_32 - (bar U_3 + bar V_2) = 24 - (24 +24) = color{blue}{-24} `
`9. Delta_33 = c_33 - (bar U_3 + bar V_3) = 13 - (24 +17) = color{blue}{-28} `
| `D_1` | `D_2` | `D_3` | `D_4` | | Supply | `bar U_i` | `S_1` | 11 [-27] | 13 [-28] | 17 [-17] | 14 | | 250 | `17` | `S_2` | 16 [-23] | 18 [-24] | 14 [-21] | 10 | | 300 | `18` | `S_3` | 21 [-24] | 24 [-24] | 13 [-28] | 10(250) | | 150 | `24` | | Demand | 200 | 225 | 275 | 0 | | | | `bar V_j` | `21` | `24` | `17` | -- | | | |
The most negative `Delta_(ij)` is -28 in cell `S_1 D_2`
The allocation to this cell is min(250,225) = 225. This satisfies the entire demand of `D_2` and leaves 250 - 225 = 25 units with `S_1`
Table-2: This leads to the following table
| `D_1` | `D_2` | `D_3` | `D_4` | | Supply | `S_1` | 11 | 13 (225) | 17 | 14 | | 25 | `S_2` | 16 | 18 | 14 | 10 | | 300 | `S_3` | 21 | 24 | 13 | 10 (250) | | 150 | | Demand | 200 | 0 | 275 | 0 | | |
Table-3: Calculate `bar U_i` and `bar V_j` (where `bar U_i` is the largest cost in row and `bar V_j` is the largest cost in column)
| `D_1` | `D_2` | `D_3` | `D_4` | | Supply | `bar U_i` | `S_1` | 11 | 13(225) | 17 | 14 | | 25 | `17` | `S_2` | 16 | 18 | 14 | 10 | | 300 | `16` | `S_3` | 21 | 24 | 13 | 10(250) | | 150 | `21` | | Demand | 200 | 0 | 275 | 0 | | | | `bar V_j` | `21` | -- | `17` | -- | | | |
2. Compute reduced cost of each cell `Delta_(ij)`, where `Delta_(ij) = c_(ij) - (bar U_i + bar V_j)`
`1. Delta_11 = c_11 - (bar U_1 + bar V_1) = 11 - (17 +21) = color{blue}{-27} `
`2. Delta_13 = c_13 - (bar U_1 + bar V_3) = 17 - (17 +17) = color{blue}{-17} `
`3. Delta_21 = c_21 - (bar U_2 + bar V_1) = 16 - (16 +21) = color{blue}{-21} `
`4. Delta_23 = c_23 - (bar U_2 + bar V_3) = 14 - (16 +17) = color{blue}{-19} `
`5. Delta_31 = c_31 - (bar U_3 + bar V_1) = 21 - (21 +21) = color{blue}{-21} `
`6. Delta_33 = c_33 - (bar U_3 + bar V_3) = 13 - (21 +17) = color{blue}{-25} `
| `D_1` | `D_2` | `D_3` | `D_4` | | Supply | `bar U_i` | `S_1` | 11 [-27] | 13(225) | 17 [-17] | 14 | | 25 | `17` | `S_2` | 16 [-21] | 18 | 14 [-19] | 10 | | 300 | `16` | `S_3` | 21 [-21] | 24 | 13 [-25] | 10(250) | | 150 | `21` | | Demand | 200 | 0 | 275 | 0 | | | | `bar V_j` | `21` | -- | `17` | -- | | | |
The most negative `Delta_(ij)` is -27 in cell `S_1 D_1`
The allocation to this cell is min(25,200) = 25. This exhausts the capacity of `S_1` and leaves 200 - 25 = 175 units with `D_1`
Table-3: This leads to the following table
| `D_1` | `D_2` | `D_3` | `D_4` | | Supply | `S_1` | 11 (25) | 13 (225) | 17 | 14 | | 0 | `S_2` | 16 | 18 | 14 | 10 | | 300 | `S_3` | 21 | 24 | 13 | 10 (250) | | 150 | | Demand | 175 | 0 | 275 | 0 | | |
Table-4: Calculate `bar U_i` and `bar V_j` (where `bar U_i` is the largest cost in row and `bar V_j` is the largest cost in column)
| `D_1` | `D_2` | `D_3` | `D_4` | | Supply | `bar U_i` | `S_1` | 11(25) | 13(225) | 17 | 14 | | 0 | -- | `S_2` | 16 | 18 | 14 | 10 | | 300 | `16` | `S_3` | 21 | 24 | 13 | 10(250) | | 150 | `21` | | Demand | 175 | 0 | 275 | 0 | | | | `bar V_j` | `21` | -- | `14` | -- | | | |
2. Compute reduced cost of each cell `Delta_(ij)`, where `Delta_(ij) = c_(ij) - (bar U_i + bar V_j)`
`1. Delta_21 = c_21 - (bar U_2 + bar V_1) = 16 - (16 +21) = color{blue}{-21} `
`2. Delta_23 = c_23 - (bar U_2 + bar V_3) = 14 - (16 +14) = color{blue}{-16} `
`3. Delta_31 = c_31 - (bar U_3 + bar V_1) = 21 - (21 +21) = color{blue}{-21} `
`4. Delta_33 = c_33 - (bar U_3 + bar V_3) = 13 - (21 +14) = color{blue}{-22} `
| `D_1` | `D_2` | `D_3` | `D_4` | | Supply | `bar U_i` | `S_1` | 11(25) | 13(225) | 17 | 14 | | 0 | -- | `S_2` | 16 [-21] | 18 | 14 [-16] | 10 | | 300 | `16` | `S_3` | 21 [-21] | 24 | 13 [-22] | 10(250) | | 150 | `21` | | Demand | 175 | 0 | 275 | 0 | | | | `bar V_j` | `21` | -- | `14` | -- | | | |
The most negative `Delta_(ij)` is -22 in cell `S_3 D_3`
The allocation to this cell is min(150,275) = 150. This exhausts the capacity of `S_3` and leaves 275 - 150 = 125 units with `D_3`
Table-4: This leads to the following table
| `D_1` | `D_2` | `D_3` | `D_4` | | Supply | `S_1` | 11 (25) | 13 (225) | 17 | 14 | | 0 | `S_2` | 16 | 18 | 14 | 10 | | 300 | `S_3` | 21 | 24 | 13 (150) | 10 (250) | | 0 | | Demand | 175 | 0 | 125 | 0 | | |
Table-5: Calculate `bar U_i` and `bar V_j` (where `bar U_i` is the largest cost in row and `bar V_j` is the largest cost in column)
| `D_1` | `D_2` | `D_3` | `D_4` | | Supply | `bar U_i` | `S_1` | 11(25) | 13(225) | 17 | 14 | | 0 | -- | `S_2` | 16 | 18 | 14 | 10 | | 300 | `16` | `S_3` | 21 | 24 | 13(150) | 10(250) | | 0 | -- | | Demand | 175 | 0 | 125 | 0 | | | | `bar V_j` | `16` | -- | `14` | -- | | | |
2. Compute reduced cost of each cell `Delta_(ij)`, where `Delta_(ij) = c_(ij) - (bar U_i + bar V_j)`
`1. Delta_21 = c_21 - (bar U_2 + bar V_1) = 16 - (16 +16) = color{blue}{-16} `
`2. Delta_23 = c_23 - (bar U_2 + bar V_3) = 14 - (16 +14) = color{blue}{-16} `
| `D_1` | `D_2` | `D_3` | `D_4` | | Supply | `bar U_i` | `S_1` | 11(25) | 13(225) | 17 | 14 | | 0 | -- | `S_2` | 16 [-16] | 18 | 14 [-16] | 10 | | 300 | `16` | `S_3` | 21 | 24 | 13(150) | 10(250) | | 0 | -- | | Demand | 175 | 0 | 125 | 0 | | | | `bar V_j` | `16` | -- | `14` | -- | | | |
The most negative `Delta_(ij)` is -16 in cell `S_2 D_3`
The allocation to this cell is min(300,125) = 125. This satisfies the entire demand of `D_3` and leaves 300 - 125 = 175 units with `S_2`
Table-5: This leads to the following table
| `D_1` | `D_2` | `D_3` | `D_4` | | Supply | `S_1` | 11 (25) | 13 (225) | 17 | 14 | | 0 | `S_2` | 16 | 18 | 14 (125) | 10 | | 175 | `S_3` | 21 | 24 | 13 (150) | 10 (250) | | 0 | | Demand | 175 | 0 | 0 | 0 | | |
Table-6: Calculate `bar U_i` and `bar V_j` (where `bar U_i` is the largest cost in row and `bar V_j` is the largest cost in column)
| `D_1` | `D_2` | `D_3` | `D_4` | | Supply | `bar U_i` | `S_1` | 11(25) | 13(225) | 17 | 14 | | 0 | -- | `S_2` | 16 | 18 | 14(125) | 10 | | 175 | `16` | `S_3` | 21 | 24 | 13(150) | 10(250) | | 0 | -- | | Demand | 175 | 0 | 0 | 0 | | | | `bar V_j` | `16` | -- | -- | -- | | | |
2. Compute reduced cost of each cell `Delta_(ij)`, where `Delta_(ij) = c_(ij) - (bar U_i + bar V_j)`
`1. Delta_21 = c_21 - (bar U_2 + bar V_1) = 16 - (16 +16) = color{blue}{-16} `
| `D_1` | `D_2` | `D_3` | `D_4` | | Supply | `bar U_i` | `S_1` | 11(25) | 13(225) | 17 | 14 | | 0 | -- | `S_2` | 16 [-16] | 18 | 14(125) | 10 | | 175 | `16` | `S_3` | 21 | 24 | 13(150) | 10(250) | | 0 | -- | | Demand | 175 | 0 | 0 | 0 | | | | `bar V_j` | `16` | -- | -- | -- | | | |
The most negative `Delta_(ij)` is -16 in cell `S_2 D_1`
The allocation to this cell is min(175,175) = 175. Table-6: This leads to the following table
| `D_1` | `D_2` | `D_3` | `D_4` | | Supply | `S_1` | 11 (25) | 13 (225) | 17 | 14 | | 0 | `S_2` | 16 (175) | 18 | 14 (125) | 10 | | 0 | `S_3` | 21 | 24 | 13 (150) | 10 (250) | | 0 | | Demand | 0 | 0 | 0 | 0 | | |
Initial feasible solution is
| `D_1` | `D_2` | `D_3` | `D_4` | | Supply | `S_1` | 11 (25) | 13 (225) | 17 | 14 | | 250 | `S_2` | 16 (175) | 18 | 14 (125) | 10 | | 300 | `S_3` | 21 | 24 | 13 (150) | 10 (250) | | 400 | | Demand | 200 | 225 | 275 | 250 | | |
The minimum total transportation cost `= 11 xx 25 + 13 xx 225 + 16 xx 175 + 14 xx 125 + 13 xx 150 + 10 xx 250 = 12200`
Here, the number of allocated cells = 6 is equal to m + n - 1 = 3 + 4 - 1 = 6 `:.` This solution is non-degenerate
This material is intended as a summary. Use your textbook for detail explanation. Any bug, improvement, feedback then
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