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8. 0-1 Integer programming problem example ( Enter your problem )
  1. Algorithm
  2. Capital Budgeting Problem - 1 example
  3. Capital Budgeting Problem - 2 example
Other related methods
  1. Formulate linear programming model
  2. Graphical method
  3. Simplex method (BigM method)
  4. Two-Phase method
  5. Primal to dual conversion
  6. Dual simplex method
  7. Integer simplex method
  8. Branch and Bound method
  9. 0-1 Integer programming problem
  10. Revised Simplex method

2. Capital Budgeting Problem - 1 example
(Previous example)
10. Revised Simplex method
(Next method)

3. Capital Budgeting Problem - 2 example





Find solution using 0-1 Integer programming problem method
MAX Z = 6500x1 + 7000x2 + 2250x3 + 2500x4
subject to
700x1 + 850x2 + 300x3 + 350x4 <= 1200
550x1 + 550x2 + 150x3 + 200x4 <= 700
400x1 + 350x2 + 100x3 <= 400
x1 + x2 >= 1
-x3 + x4 <= 1
and x1,x2,x3,x4 >= 0


Solution:
To apply branch and bound method, the following 4 constraints have to be added to the LP model.
`x_1<=1`

`x_2<=1`

`x_3<=1`

`x_4<=1`

Solution steps by BigM method

Max `Z``=````6500``x_1`` + ``7000``x_2`` + ``2250``x_3`` + ``2500``x_4`
subject to
```700``x_1`` + ``850``x_2`` + ``300``x_3`` + ``350``x_4``1200`
```550``x_1`` + ``550``x_2`` + ``150``x_3`` + ``200``x_4``700`
```400``x_1`` + ``350``x_2`` + ``100``x_3``400`
`````x_1`` + ````x_2``1`
` - ````x_3`` + ````x_4``1`
`````x_1``1`
`````x_2``1`
`````x_3``1`
`````x_4``1`
and `x_1,x_2,x_3,x_4 >= 0; `


Solution is
Max `Z_(A)=9062.5` `(x_1=0,x_2=1,x_3=0.5,x_4=0.375)`

and `Z_L=7000` `(x_1=0,x_2=1,x_3=0,x_4=0)` obtainted by the rounded off solution values.

The branch and bound diagram
A
`x_1=0,x_2=1,x_3=0.5,x_4=0.375`
`Z_A=9062.5`
`Z_L=7000`
Solution steps by
BigM method


In Sub-problem A, `x_3(=0.5)` must be an integer value, so two new constraints are created, `x_3=0` and `x_3=1`

Sub-problem B : Solution is found by adding `x_3=0`.
Solution steps by BigM method
Max `Z``=````6500``x_1`` + ``7000``x_2`` + ``2250``x_3`` + ``2500``x_4`
subject to
```700``x_1`` + ``850``x_2`` + ``300``x_3`` + ``350``x_4``1200`
```550``x_1`` + ``550``x_2`` + ``150``x_3`` + ``200``x_4``700`
```400``x_1`` + ``350``x_2`` + ``100``x_3``400`
`````x_1`` + ````x_2``1`
` - ````x_3`` + ````x_4``1`
`````x_1``1`
`````x_2``1`
`````x_3``1`
`````x_4``1`
`````x_3`=`0`
and `x_1,x_2,x_3,x_4 >= 0; `

Solution is
Max `Z_(B)=8875` `(x_1=0,x_2=1,x_3=0,x_4=0.75)`
and `Z_L=7000` `(x_1=0,x_2=1,x_3=0,x_4=0)` obtainted by the rounded off solution values.
Sub-problem C : Solution is found by adding `x_3=1`.
Solution steps by BigM method
Max `Z``=````6500``x_1`` + ``7000``x_2`` + ``2250``x_3`` + ``2500``x_4`
subject to
```700``x_1`` + ``850``x_2`` + ``300``x_3`` + ``350``x_4``1200`
```550``x_1`` + ``550``x_2`` + ``150``x_3`` + ``200``x_4``700`
```400``x_1`` + ``350``x_2`` + ``100``x_3``400`
`````x_1`` + ````x_2``1`
` - ````x_3`` + ````x_4``1`
`````x_1``1`
`````x_2``1`
`````x_3``1`
`````x_4``1`
`````x_3`=`1`
and `x_1,x_2,x_3,x_4 >= 0; `

Solution is
This Problem has an infeasible solution, so this branch is terminated.




The branch and bound diagram
A
`x_1=0,x_2=1,x_3=0.5,x_4=0.375`
`Z_A=9062.5`
`Z_L=7000`
Solution steps by
BigM method
`x_3=0``x_3=1`
B
`x_1=0,x_2=1,x_3=0,x_4=0.75`
`Z_B=8875`
`Z_L=7000`
Solution steps by
BigM method
C

Infeasible Solution

Solution steps by
BigM method




In Sub-problem B, `x_4(=0.75)` must be an integer value, so two new constraints are created, `x_4=0` and `x_4=1`

Sub-problem D : Solution is found by adding `x_4=0`.
Solution steps by BigM method
Max `Z``=````6500``x_1`` + ``7000``x_2`` + ``2250``x_3`` + ``2500``x_4`
subject to
```700``x_1`` + ``850``x_2`` + ``300``x_3`` + ``350``x_4``1200`
```550``x_1`` + ``550``x_2`` + ``150``x_3`` + ``200``x_4``700`
```400``x_1`` + ``350``x_2`` + ``100``x_3``400`
`````x_1`` + ````x_2``1`
` - ````x_3`` + ````x_4``1`
`````x_1``1`
`````x_2``1`
`````x_3``1`
`````x_4``1`
`````x_3`=`0`
`````x_4`=`0`
and `x_1,x_2,x_3,x_4 >= 0; `

Solution is
Max `Z_(D)=7812.5` `(x_1=0.125,x_2=1,x_3=0,x_4=0)`
and `Z_L=7000` `(x_1=0,x_2=1,x_3=0,x_4=0)` obtainted by the rounded off solution values.
Sub-problem E : Solution is found by adding `x_4=1`.
Solution steps by BigM method
Max `Z``=````6500``x_1`` + ``7000``x_2`` + ``2250``x_3`` + ``2500``x_4`
subject to
```700``x_1`` + ``850``x_2`` + ``300``x_3`` + ``350``x_4``1200`
```550``x_1`` + ``550``x_2`` + ``150``x_3`` + ``200``x_4``700`
```400``x_1`` + ``350``x_2`` + ``100``x_3``400`
`````x_1`` + ````x_2``1`
` - ````x_3`` + ````x_4``1`
`````x_1``1`
`````x_2``1`
`````x_3``1`
`````x_4``1`
`````x_3`=`0`
`````x_4`=`1`
and `x_1,x_2,x_3,x_4 >= 0; `

Solution is
This Problem has an infeasible solution, so this branch is terminated.




The branch and bound diagram
A
`x_1=0,x_2=1,x_3=0.5,x_4=0.375`
`Z_A=9062.5`
`Z_L=7000`
Solution steps by
BigM method
`x_3=0``x_3=1`
B
`x_1=0,x_2=1,x_3=0,x_4=0.75`
`Z_B=8875`
`Z_L=7000`
Solution steps by
BigM method
C

Infeasible Solution

Solution steps by
BigM method
`x_4=0``x_4=1`
D
`x_1=0.125,x_2=1,x_3=0,x_4=0`
`Z_D=7812.5`
`Z_L=7000`
Solution steps by
BigM method
E

Infeasible Solution

Solution steps by
BigM method




In Sub-problem D, `x_1(=0.125)` must be an integer value, so two new constraints are created, `x_1=0` and `x_1=1`

Sub-problem F : Solution is found by adding `x_1=0`.
Solution steps by BigM method
Max `Z``=````6500``x_1`` + ``7000``x_2`` + ``2250``x_3`` + ``2500``x_4`
subject to
```700``x_1`` + ``850``x_2`` + ``300``x_3`` + ``350``x_4``1200`
```550``x_1`` + ``550``x_2`` + ``150``x_3`` + ``200``x_4``700`
```400``x_1`` + ``350``x_2`` + ``100``x_3``400`
`````x_1`` + ````x_2``1`
` - ````x_3`` + ````x_4``1`
`````x_1``1`
`````x_2``1`
`````x_3``1`
`````x_4``1`
`````x_3`=`0`
`````x_4`=`0`
`````x_1`=`0`
and `x_1,x_2,x_3,x_4 >= 0; `

Solution is
Max `Z_(F)=7000` `(x_1=0,x_2=1,x_3=0,x_4=0)`
and `Z_L=7000` `(x_1=0,x_2=1,x_3=0,x_4=0)` obtainted by the rounded off solution values.
This Problem has integer solution, so no further branching is required.
Sub-problem G : Solution is found by adding `x_1=1`.
Solution steps by BigM method
Max `Z``=````6500``x_1`` + ``7000``x_2`` + ``2250``x_3`` + ``2500``x_4`
subject to
```700``x_1`` + ``850``x_2`` + ``300``x_3`` + ``350``x_4``1200`
```550``x_1`` + ``550``x_2`` + ``150``x_3`` + ``200``x_4``700`
```400``x_1`` + ``350``x_2`` + ``100``x_3``400`
`````x_1`` + ````x_2``1`
` - ````x_3`` + ````x_4``1`
`````x_1``1`
`````x_2``1`
`````x_3``1`
`````x_4``1`
`````x_3`=`0`
`````x_4`=`0`
`````x_1`=`1`
and `x_1,x_2,x_3,x_4 >= 0; `

Solution is
Max `Z_(G)=6500` `(x_1=1,x_2=0,x_3=0,x_4=0)`
and `Z_L=6500` `(x_1=1,x_2=0,x_3=0,x_4=0)` obtainted by the rounded off solution values.
This Problem has integer solution, so no further branching is required.




The branch and bound diagram
A
`x_1=0,x_2=1,x_3=0.5,x_4=0.375`
`Z_A=9062.5`
`Z_L=7000`
Solution steps by
BigM method
`x_3=0``x_3=1`
B
`x_1=0,x_2=1,x_3=0,x_4=0.75`
`Z_B=8875`
`Z_L=7000`
Solution steps by
BigM method
C

Infeasible Solution

Solution steps by
BigM method
`x_4=0``x_4=1`
D
`x_1=0.125,x_2=1,x_3=0,x_4=0`
`Z_D=7812.5`
`Z_L=7000`
Solution steps by
BigM method
E

Infeasible Solution

Solution steps by
BigM method
`x_1=0``x_1=1`
F
`x_1=0,x_2=1,x_3=0,x_4=0`
`Z_F=7000`
`Z_L=7000`
Solution steps by
BigM method
G
`x_1=1,x_2=0,x_3=0,x_4=0`
`Z_G=6500`
`Z_L=6500`
Solution steps by
BigM method




The 0-1 Integer programming problem algorithm thus terminated and the optimal integer solution is :
`Z_(F)=7000` and `x_1=0,x_2=1,x_3=0,x_4=0`




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2. Capital Budgeting Problem - 1 example
(Previous example)
10. Revised Simplex method
(Next method)





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