Trouble Coding a Constraint for Solver

[dmcmillon86]

Hi everybody,

This is my first post, so please let me know if I don't follow the forum conventions, but I think I've got it so here goes.

I have a macro that is running solver to optimize routes. I have a set of rows set up with indices linked to drivetimes and time windows. I need solver to manipulate the indices so that the route time is under a limit, delivery windows are met, and there are no duplicate stops. I need it to be a macro because we're going to be running it with different data sets, but I know there is a feasible solution because I've found one myself manually for one of our sets, and when I have the solution input already into the variable cells and run solver, solver confirms my solution and presents no problems. If I don't have the solution already entered in, however, solver says it can not find a feasible solution.

I suspect this is because the way I have set up my constraints won't allow solver any wiggle room without violating a constraint, but I don't know for sure.

Does anyone have any suggestions?

Thank you.

[shg]

Welcome to the forum.

No one is going to be able to help you in the abstract. Post a workbook and explain clearly what you're trying to do in context.

[dmcmillon86]

Here is my file. I'm sorry it is not well commented. I'm new to VBA and not very good at that. I removed some of the sheets with private company info, so the time window checks don't work on this version. I'm pretty sure that's not the problem, though. Basically I can't get solver to even try using the unique integer values in different orders.

[Alf]

One thing I noticed. In the

Public Function DISCSUM(MixRange As Range) As Double

you need to add the line

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Alf

[dmcmillon86]

Thank you, Alf
That solved some other problems I was having.
As for the solver problem, I switched to the Evolutionary solver and my problem was solved. Thank you everyone who checked out my issue and put thought into it.

[dmcmillon86]

Could you mark ny problem as solved?
Asking you is the correct thing to do, rgiht?

Thank you

[Alf]

Could you mark ny problem as solved?
Asking you is the correct thing to do, rgiht?

No, you mark your problem solved yourself because you is the only person that can decide if your problem is solved. As to how to do it see quote from forum rules.

If your problem is solved, please say so clearly, and mark your thread as Solved: Click the Edit button on your first post in the thread, Click Go Advanced, select [SOLVED] from the Prefix dropdown, then click Save Changes. If more than two days have elapsed, the Edit button will not appear -- ask a moderator to mark it.

Alf

[dmcmillon86]

Thank you, Alf