Freeoperators function

Hi everybody,
I have a question about the freeoperators function.


The logic I want to model is the following: an operator takes boxes from a queue to a processor. However I don’t want the operator to start transporting the box after the processor is available, but to wait with the box beside the processor until it is available.
I tried modeling it as in the first model: with an additional queue before the processor. The origin queue creates a task sequence in the request transport from picklist, which is the basic transport task sequence with an additional task at the end: utilize. My idea was to free the operator once the box would leave the queue (OnExit trigger) with the freeoperator function. But this didn’t work, the operator never got freed.
So I tried the second model, which is the same logic as the first model, except that I replaced the second queue by a processor with a process time of 0, and the freeoperator is in the OnFinishProcess trigger. And this time I was able to obtain that logic.

I would like to know if the freeoperator only works for the process triggers (OnFinishSetUp and OnFinishProcess) or if I need to change something in the first model for it to work.


Thank you very much for your help!


Lucie

The comparison would be to put freeoperators on the exit of the queue, but there is a timing issue with that since when you unload the item to the queue, it is immediately released to the processor before the operator enters the UTILIZE task. The difference in the second example is that you have a zero time delay before the item is processed and that's enough for the operator to enter the UTILIZE task. So there's nothing special about freeoperators and those other triggers other than the difference in timing.

One solution, if you wanted, would be to call a subtask to conditionally add a UTILIZE TASK if the queue is not empty.