I have a DMN task inside of a parallel multi instance task that put his output in a result variable. The problem appears after that DMN task on the gateway, when I evaluate the result variable.
When there are two processes within the multi instance task, with different attributes, then the DMN output should be A for process 1 and B for process 2. But it seems like its always the same value after the first decision of the DMN, but random every time I tried it.
So one of the two processes inside the multi instance take the wrong way after the gateway, because the result variable isnt unique for every multi instance execution.
I hope it is only a problem in my configuration and not by design, that the result variable isnt unique for multi instances?
A multi-instance activity ends when all instances are finished.
That means, that all tasks are executed before the process gets to your gateway. And the problem you are having is, that every DMN-task of your multi-instance writes the output to the same result variable. So this variable gets constantly overwritten and only contains the result of the last DMN-task.
So you should consider creating an object that holds all the results of the DMN-tasks.
Here is a good forum post that helped me to improve the usage of my multi-instance tasks: