Allow a token to pass contingent on the contents of a list.

[Gavin_DouglasH8UFN]

I have a push to list activity that is tied to a local list.  As tokens arrive I pass the token and a label named "type" to that list.  I want to keep a token in another location of the model from advancing in the process flow if, say, the number of entries of type "A" in the list is less than 30.  I want to avoid using a decide if possible.  The contents of the list will be updated by other tokens in the model and not the ones looking to 'pass.'  I hope this makes sense.

[FelixMoehlmann · Accepted solution]

The attached model presents a possible solution for a local list in an Object Process Flow. I track the list content by type by creating a separate token for each value that gets pushed to the list. These copy the Type label and enter a Zone that is partitioned by Type. It is then possible to wait for the content of a particular partition to reach a given value.

This is sort of the "worst case" scenario. The solution can be simplified if certain assumptions can be made:

- The tokens that are pushed to the list can enter the Zone themselves (possible if they stay in the Push to List activity until they are pulled)

- The Type label is used as partition ID on the list itself.

- The list is not part of an Object Process Flow.

- A global list partitioned by Type can be used instead.

[Gavin_DouglasH8UFN · Accepted solution]

Thanks for the help.