Moving same itemtype to the next similar queue when current queue is full

Hi all,

I have a problem moving the same itemtype of item to the next queue when the first queue is fully filled.

Please kindly refer to the attached powerpoint slides for clearer information. Any suggestion?

thank you so much!

Hendry

To simplify the model, only 1 item is released from the source until the finished product is being moved into the downstream queue, then the next one will continue.

Thank you

Hendry

Hello Hendry,

please look into the Source Codes of items from the picklist Send To wherein you find the phrase if available. Try to adapt these methods into your source code or build your code starting with such source code.
The source code build a balance of items already in transit and free storing capacity. When the capacity is depleted then the code should switch to the next available queue. If you look into the source codes there will be a value from the node numberoftransportin. That describe the items in transit. The tasksequence has been written, but maybe the taskexecuter has only stored this tasksequence into thetasksequence queue.
Generally your model should work without any Taskexecuters. They just support your model. A well build model doesn't depend on the structure of the Taskexecuters. You should always switch the use of transport on or off. If you shape a special distribution logic of the tasksequences then it should be fully independent from the material flow of your model.

Jörg

Hi Jorg

I got your interesting points!

"You should always switch the use of transport on or off. If you shape a special distribution logic of the tasksequences then it should be fully independent from the material flow of your model."

As a beginner of FlexSim user, this is my main problem. Most of the time, I do not really understand how to shape the special distribution logic of the tasksequences you mentioned.

Do you have any idea where I can read more about the distribution logic of tasksequences so that the material flow would not rely or get intercepted by TE? (other than the "User Manual" in flexsim?)

Hendry

Hi Hendry,

as I know there isn't any documentation about tasksequences than the manual or the threads here in the forum mostly by the developers or distributors.
Every Taskexecuter is by default a dispatcher. But if you place a dispatcher previous to a taskexecuter the flexsim engine transfers only one tasksequence to a taskexecuter. The order of the transfer depends on the rank of the tasksequencequeue. If you sort the queue you can change the order in the function Queue Strategy. The function Pass To let you decide which taskexecuter does the job.
The picklist options to manipulate a tasksequence are expecting the standard tasksequences: transporting items or utilize tasksequence. They are described in the manual.
If you build an own Tasksequence you have to adjust those picklist options to fit to your sequence.
Jörg

Hi Jorg

Thanks again for your information. I will try to sort tasksequencequeue so that it fits the sequence I want it to work.

Hendry

Henry

Looking at your issue from the PPT, you want to send the flowitem to Q2 and Q2.1. Q2.1 will be used after Q2 is filled. My suggestion is instead of using PUSH flowitem from Q1, you should be using PULL from Q2 and Q2.1 where you can specify the flowitem that you want to pull in. Your connection from Q1 to Q2 should be lower than Q2.1. That is if Q1 to Q2 is output port of 2, then your Q1 to Q2.1 should be 3 or lower.

Let me know if this work

Hi David,

The PULL method you have mentioned does improve my model. However, what I did was a little bit different from yours:
1. ONLY Q2.1 would PULL the item from its upstream queue whereas Q2 dont. (this step alone is not enough for the model to work)
2. So when I accidentally tick "re-evaluate Sendto Downstream Availability" in the upstream queue, the model works ideally (which I do not really know why.......................)

Thanks so much for your reply. Really appreciate it!