about port selecct

Hi, In the attachment, I want the blue items to go out only after the red items all go out.

how to do it?

thanks

Maybe I should make my question more clear.

It seems that the queue in flexsim is not an absolute FIFO queue. In the above model, two types of item go into a queue, then in the sendto trigger, I make Item1 to port 1, Item2 to port 2.

I find that item2 will go out to port 2 even if there is item1 before it. In most cases, this is what we want. But in some cases, it's not.

So, if I want an absolute FIFO queue, how to get it?

Qin Tian,

The easiest way in my eyes is, and that’s what I teach in my training classes, is to add an additional queue with max content (capacity) of 1 and decrease the max content of the original queue by 1 that you do not change the total capacity. That’s an easy solution, right?

By the way, I like that in Flexsim the queue is not an absolute FIFO queue, because it is really hard (or let’s say some effort) in other simulation packages (at least in the ones I know) to make a queue like we have in Flexsim that items which are able to leave to their target destination just leave.

Qin,

If you want absolute FIFO in your queue then the best way is to have the down stream objects pull and set the pull requirement to the code below:

if(getrank(item) == 1) return 1;
else return 0;

This will make it so only the first item will leave. You will also want to check the reevalute pull requirement box.

Brandon