Setting the source using a Weibull distribution in a job shop model

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AmyTsai asked May 6, '24 AmyTsai commented 6 days ago

Setting the source using a Weibull distribution in a job shop model

I'm encountering an issue with my FlexSim jobshop. I'm trying to add two item parts from my source and apply a statistical Weibull distribution to them. Although I've configured the inter-arrival time in the source using the Weibull distribution, it's not functioning correctly. My objective is to route these two items from the source (based on a Weibull distribution) to the processor, following the routing table. Afterward, they should pass through a combiner for merging before returning to the processor and eventually reaching the sink. Can you assist me in resolving the setup problem with the source using the Weibull distribution? jobshop 11 combiner problem 5.fsm 螢幕擷取畫面-2024-05-06-103800.png 螢幕擷取畫面-2024-05-06-104015.png 螢幕擷取畫面-2024-05-06-103727.png

Software Version:

FlexSim 22.2.4

setting the source using a weibull distribution in a job shop model

螢幕擷取畫面-2024-05-06-103800.png (370.2 KiB)

螢幕擷取畫面-2024-05-06-104015.png (358.3 KiB)

螢幕擷取畫面-2024-05-06-103727.png (368.5 KiB)

jobshop-11-combiner-problem-5.fsm (49.4 KiB)

Answer 1 · 2024-05-06T06:20:14Z

Felix Möhlmann answered May 6, '24 AmyTsai commented 6 days ago

In the creation trigger of the source you are trying to set an item color based on the "Type" label which does not exist on the item. This causes the entire creation trigger to stop with an error message and the "process" and "Station" labels are also not assigned. This then leads to additional errors when the processors try to pull the item based on the "Station" label.

In short: You need to add the "Type" label first in the On Creation trigger.

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AmyTsai commented · May 07 at 01:57 AM

Thank you for providing the information. I already add the "Type" new label to the source of the on-creation trigger, but it didn't work. So I tried set color by case on trigger creation source, which functioned well when I used the arrival schedule with a table. However, it failed when I used the inter-arrival time with a Weibull statistical distribution. My goal is to apply different statistical distributions to two items from the source. How should I configure the settings to allow two items from the source to run with distinct statistical distributions? jobshop 11 combiner problem 6.fsm

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jobshop-11-combiner-problem-6.fsm (61.4 KiB)

Felix Möhlmann AmyTsai commented · May 07 at 07:31 AM

I'm not really sure what exacly you mean with "two items [...] run with distince statistical distributions". Which value is the distribution used for: The type, the inter-arrival time (as a whole or per type)?

Adding a type label in the trigger should work. Maybe you ran into the issue that can sometimes occur when changing the order of functions in a trigger. Parentheses in the code can end up in a comment line and thus break the code. You can usually fix this by manually adding a new line between the distince trigger options in the code.

I also noticed that station2's preempt option currently aborts other tasks, which eventually breaks the correct flow of items.

jobshop-11-combiner-problem-7.fsm

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jobshop-11-combiner-problem-7.fsm (49.4 KiB)

AmyTsai commented · May 08 at 03:01 AM

Thank you for providing guidance and detailed feedback. We successfully implemented the statistical distribution from the source, and it worked. We apologize for any previous lack of clarity in our question. our question before about “two[…]run with distinct statistical distributions” is we want each item to have a different statistical distribution from the source."

I have already uploaded the updated FlexSim model. In this model, we have 4 items from the source, and we want each of these 4 items to have a different statistical distribution. Additionally, we want to create different batches for each item and process. For example : Let say Product 1's batch consists of 10 items. When Product 1 enter Station 1, Station 1 must wait until all 10 items of Product 1 are present before Station 1 can begin processing. During the processing of Product 1, Station 1 cannot process any other product.

Could you please assist us in addressing the issues of implementing different statistical distributions and managing batch for the different product and processing? Your help is greatly appreciated. jobshop Batch Problem 2.fsm

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jobshop-batch-problem-2.fsm (50.7 KiB)

Joerg Vogel AmyTsai commented · May 08 at 04:56 AM

@AmyTsai, collect 10 items and release them when process has finished is a mode of a combiner:

In batch mode, the combiner simply releases all the flow items once the batch is collected and the setup and process times have finished.

from: https://docs.flexsim.com/en/22.2/Reference/3DObjects/FixedResources/Combiner/Combiner.html#overview

how you can collect 10 items ( 1 container and 9 items of a component list) is a feature of a picklist option in On Entry).

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AmyTsai commented · May 08 at 06:21 AM

I apologize for any confusion. Allow me to clarify. We have four items from a source: Product 1, Product 2, Product 3, and Product 4. Each of these items has a different statistical distribution from source.

Additionally, Each item has a different batch quantity. For example, the batch of Product 1 is 10 pieces. When product 1 enters Station 1, the station must wait until it has received all 10 pieces of Product 1 before processing them individually. During the process time, Station 1 cannot process any other items. This same principle applies to the other items.

I think using a combiner may not be the optimal solution for this problem. Could you please provide an example or explain how to configure each item's have different statistical distribution and batch quantity? This will help us better understand and address the issue. Thank you. jobshop-batch-problem-2 (1).fsm

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jobshop-batch-problem-2-1.fsm (50.7 KiB)

Felix Möhlmann AmyTsai commented · May 08 at 11:00 AM

You are going to have a much easier time building the batching logic in Process Flow. I have attached an example of how this could look.

For different arrival distributions for the types you will have to use one source per type.

jobshop-batch-problem-2-fm.fsm

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jobshop-batch-problem-2-fm.fsm (62.4 KiB)

AmyTsai commented · 6 days ago

Thank you so much for providing the guidance and example feedback! We've implemented the batching logic in Process Flow and different arrival distributions for the types as you suggested, and we are happy to report that the model runs successfully. Your insights were incredibly helpful in streamlining the process. Thanks again!

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Setting the source using a Weibull distribution in a job shop model

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