Pull strategy not working when filtering by item age

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Joaquín MSV asked Jul 17, '24 Felix Möhlmann answered Jul 17, '24

Pull strategy not working when filtering by item age

Hello,

I have a doubt on how the pull strategy shoud be addressed when applied to a queue (or any other element) if I want to filter by multiple criteria and "age" of item must be included.

Attached is a very simple model with a sourcing queue tha pushes into a global item list and then 3 other queues that demand elements based on the "Type" and "age". If I leave the "Type" filter only in the query, it works perfectly fine, but if I filter by "age" value, no element is pulled.

So, basically why "WHERE Type == 1" works and not "WHERE Type == 1 AND age >= 10" doesn't? Or just "WHERE age >= 10" doesn't work either as query.

Which is the error and the proper way of dealing with filtering dynamic properties like age?

Thanks in advance.

test_pull_strategy.fsm

Software Version:

FlexSim 24.0.4

queue pull strategy list age

test-pull-strategy.fsm (32.8 KiB)

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Answer 1 · 2024-07-17T12:33:03Z

Felix Möhlmann answered Jul 17, '24

The query is evaluated against pushed items once when they are pushed. At that point the age condition is of course not fulfilled, so the item is not pulled and a back order is created. The back order by default only checks newly pushed values.

There are two options that can allow the queues to actually pull something (there are also more complicated solutions, but let's stick with these for now).

You can check the "Reevaluate All Values On Push" which will cause a back order to check all items on the list again when a new one is pushed.

You can also define one or multiple "Back Order Reevaluation Events".

1721219485026.png (19.2 KiB)

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