# Lock/Exclude in Binary Constraint

#### laxin

##### New Member
I am using the binary constraint for an optimization tool. Currently am trying to include a feature that can either lock in a certain row during the optimization or exclude it by either putting an L or an X in a column that will correspond to the set of data within its row. Essentially, if their is an L, the price corresponding to that row will be optimized around, and if their is an X, it will be excluded from the optimization.

Im still new to solver and I don't really know where to start here. If anyone can help me out or point me in the right direction, it would be greatly appreciated!

bump... help?

#### Juan Pablo González

##### MrExcel MVP
From here you can see that a binary constraint is one that can either take a 1 or a 0. So, you can keep your L / X, but use them in a separate cell. In other words, you need two cells: One, say A1, that holds the binary constraint (1 or 0), and in B1, a formula like

=IF(A1=1,"L","X")

#### laxin

##### New Member
From here you can see that a binary constraint is one that can either take a 1 or a 0. So, you can keep your L / X, but use them in a separate cell. In other words, you need two cells: One, say A1, that holds the binary constraint (1 or 0), and in B1, a formula like

=IF(A1=1,"L","X")
Will that be factored in by solver during the operation? Thats what I need ... Im not sure its that simple, but Im no expert

#### Juan Pablo González

##### MrExcel MVP
Will that be factored in by solver during the operation? Thats what I need ... Im not sure its that simple, but Im no expert
Yes, if you set A1 to be a binary constraint, it will be used by Solver, and if your model depends on B1, then the formulas will autocalculate and Solver will see that.

#### laxin

##### New Member
From here you can see that a binary constraint is one that can either take a 1 or a 0. So, you can keep your L / X, but use them in a separate cell. In other words, you need two cells: One, say A1, that holds the binary constraint (1 or 0), and in B1, a formula like

=IF(A1=1,"L","X")
The L or the X notation doesnt matter. I can use 1 and 0 too. I just need the solver/optimization to read the column with whatever on/off, 1/0, true/false, lock/exclude notation to either lock the row within the optimization or exclude it entirely.

My true problem is essentially this:

 Binary Name Output Lock/Exclude Price a L 200 b 250 c 300 d 400 e X 375 f 310 g 275

<tbody>
</tbody>

max price is, say, 800. I want to maximize the output within the max price. In column A, there will be a 0 if the person is not included in the optimized result, and 1 if they are.

The program runs to this point. I am trying to add a feature where I can lock/exclude a person from the optimization. I have not been able to figure this out yet

#### laxin

##### New Member
Bump, still need help if anyone can

#### Juan Pablo González

##### MrExcel MVP
If I understand you correctly, in the "Output" column, which starts in C2, I put the following formula:

Code:
=E2*IF(D2="L",1,IF(D2="X",0,A2))
Then in C9 I put the total of the column

Code:
=SUM(C2:C8)
I also put in C11 the "Max Price" allowed, 800.

Now, I defined the solver model as follows:

Set Objective: C9
To: MAX

Constraints:
A2:A8 = binary
C9 <= C11