Hello,
I have a problem in the attached model; a token stuck in "Push to List" activity (may be because the push value is not correct) resulting on the stuck tokens in the "Acquire OPMP" activity (figure).
Would you please help me to fix this?
(FlexSim 19.0.0)
It appears that you're pushing the token itself to the list. The token doesn't have the "SC" label, so it won't be able to be pulled by another activity based on the "SC" query. What is it that you intended to push to the list?
Also, keep in mind that a token can't move on from the Push to List activity until it's been pulled from the list. So, if all your tokens are pushed to the list, there won't be any left to pull.
@tanner.p, I am trying to do the following:
Tokens in "Acquire OPMP" activity are pulled by "Pull from List OPMP 3" according to their SC values. When a token is pulled, we attribute to it a new labels values in "Assign Labels". Then we do a test by "Pull from List OPMP 2": if there is no token in the list "ListOPMP" we select the tote corresponding to the pulled token and load it on the combiner... if there is a token in the list "ListOPMP" we must get back the pulled token/item in the list "EmptyCUtotes" by "Push to List" because after the list " ListOPMP" becomes empty ("Wait for Event " activity) this token returns to "Acquire OPMP" and it will be re-pulled by "Pull from List OPMP 3" (the reason for this is to allow the evaluation of the SC values of all tokens, those present on the rack15 and the coming ones).
I think that the problem is that the list "EmptyCUtotes" contains the pushed items (CUtotes) (figure1) while in the processflow I am pushing a token. I tried to set the "push value" equal to token.CUtote but it is not working too.
I hope I make it clear what I want to do. I would be grateful for your help.
Hi @sara.s2,
In looking through our old cases I see that we missed answering your latest comment from Aug 18.
Are you still working on this problem? If so, please comment back to let us know your current status and how we can help.
If we don't hear back within 3 business days, we'll assume you were able to answer your question and we'll close this out of our tracking. You can always comment back to reopen the issue.
I understand your logic, but there are some events that we need to change. The biggest issue is that no matter what you push to the list in the Process Flow activity, that token still has the acquired resource. This means that the other tokens cannot acquire a resource.
If the tokens at the Acquire activity can't acquire a resource, they can't pull from the list. If they can't pull from the list, then the token at the Push to List activity can't progress. If the token at the Push to List activity can't progress, it can't release the resource. If the resource isn't released, the tokens at the Acquire resource can't progress.
Essentially, the model is in deadlock. We need to change three things:
1) The Release resource activity needs to happen before the Push to List.
2) The Push to List value should be token.EmptyCUTotes or token.CUTote (it shouldn't matter too much because it points to the same item).
3) The Partition ID needs to be the same for all tokens. Some have "None" and some have "0" in the model. You'll have to decide what you'd like to do for a Partition ID. If you can't sort this out, I recommend changing the logic to move the items out of Rack15 and then back in. This way, the items are re-evaluated properly according to their SC values. I've included a second version that you can try out.
I also just realized that the "CUtote arrives to rack" activity already has a reference to the CUTote, so pulling one of the CUtotes from the list with a token that already references one of the CUtotes seems really redundant to me. I'm not sure I would set up the Process Flow just like this, but rather use a single token that handles all the logic.
Hope this helps! Let me know if this model works.
First version: trying1 (6)_1.fsm
Second version: trying1 (6)_2.fsm
@tanner.p, what I am trying to do is to find a solution for a trouble that I had in the main project that I am working on:
Before I added the activities in red (figure1), there was no problem in the model (figure2). After I added them (to perform an effective selection of the priority totes that have the lowest SC value), tokens stuck in the “ProcessFlowCU” (figure3). I don't know the reason of this trouble. So I tried to put "Pull from List OPMP 2" activity after "Pull from List OPMP 3" and “Assign Labels” activities, this is why I added "Push to List" activity. But this is not working ! your instructions helped me and I thank you very much but the idea of pushing to list is not the right solution.
The model I usually load (“trying1”) is just a shallow example of the project that I am not allowed to load.
To be noted that I had the same trouble before you helped me in my question “Troubles in the triggering tokens and query order”.
I know it is difficult for you to determine the reason of the trouble without the model, but please could you just give me some instructions to check in the model and send you feedback using only figures? I would be grateful for your help.
@tanner.p, would you please reply. If you need the model to solve this problem, I will load it in private mode.
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