Why does Balance command not reach its threshold

I used balance command before I run the simulation(after minimize command) and I found this in log document:

I don’t understand why it stoped at 6th iteration when the imbalanced factor didn’t reach 1.1(still larger than 1.1)
Thanks for your help in advance.

Do you have any indication that it should get a lower imbalance?
Is your structure that homogeneously distributed?
Since you are just shifting subdomain boundaries, it is not always possible to achieve perfect balance. For illustration see the images in the balance command documentation; those show how this can happen in 2d, in 3d this kind of situation is even easier to come by. Sometimes this can be resolved by changing how the subdomains are divided across the processors with the “processors” command, but without seeing what your system looks like, it is very difficult to make a specific assessment of why load balancing behaves the way it does.

Please also note, that the “balance” command is only the second option the improve load balance. Using “processors” in a smart way can often eliminate the need for it.

I know it is not always possible to achieve perfect balance for this command, but I don’t know why it stopped before its maximum iteration times.

Because it was not improving anymore.