Solver Iterations-how to change number
 

Hi,

When I try to change the number of solver iterations I can't seem to
actually get it to do more than about 5. I walked through the iterations
step-by-step and after about 5 iterations it quits. If I start from that
solution a couple more times it gets to the solution, so I seem to have a
simple problem that only requires about 15 iterations but changing the number
of iterations allowed doesn't seem to have an effect. I have tried
everything that seems obvious.

Thanks.

Solver Iterations-how to change number
 

In Help, under "Troubleshoot Solver," there are a number of reasons
why Solver might stop prematurely. For instance, "For problems with
integer constraints, you need to decrease the Tolerance setting in the
Solver Options dialog box so that Solver can find a better integer
solution."

If that example isn't the problem, you might want to peruse the
others.

Mark Lincoln

On Sep 27, 3:04 pm, Rick Hicks <Rick
wrote:
Hi,

When I try to change the number of solver iterations I can't seem to
actually get it to do more than about 5. I walked through the iterations
step-by-step and after about 5 iterations it quits. If I start from that
solution a couple more times it gets to the solution, so I seem to have a
simple problem that only requires about 15 iterations but changing the number
of iterations allowed doesn't seem to have an effect. I have tried
everything that seems obvious.

Thanks.

Solver Iterations-how to change number
 

If it quits, then Solver cannot improve the solution or it converges on a
value. Have you played with all the options in Solver? Have you decreased
the convergence?

Otherwise, perhaps you really are at the optimal value. I've found that
when setup correctly, Solver is pretty darn accurate. With all due respect
to PivotTables, I believe Solver is the most powerful and useful tool (at
least to us engineers).

Matthew Pfluger

"Rick Hicks" wrote:

Hi,

When I try to change the number of solver iterations I can't seem to
actually get it to do more than about 5. I walked through the iterations
step-by-step and after about 5 iterations it quits. If I start from that
solution a couple more times it gets to the solution, so I seem to have a
simple problem that only requires about 15 iterations but changing the number
of iterations allowed doesn't seem to have an effect. I have tried
everything that seems obvious.

Thanks.

Solver Iterations-how to change number
 

Thanks,

I found the problem in the troubleshooting. I didn't know if it was
something I would find there or if it was a trick that one of you experts
would know (the first time I trolled this site the result to my problem was a
clever little wrinkle). It turns out I got tired of looking right before I
got to it.

For anyone else stumbling onto this thread in the future, the problem I was
seeing was a "...could not find a feasible solution" message after a few
iterations. The solver would eventually work if I redid it a few times,
restarting with the previous run's results for my variables.

The solution was to check the "Use automatic scaling" box. I have a problem
where my variables range from 1 mil to 10 mil and when I start with all of
them at zero the range is too wide for the solver to deal with.

Thanks again for the help. Know there wasn't a special "trick" helped a lot.

Rick