I'm currently doing a project that requires me to make an assembly line with different palatized parts going through it. So far I've managed to get 2 different item types through the processor with different operation times however I'm struggling to set a limit of 1 of each item on the processor at once. Currently the processor will take 1 of each item at the start, then it will take one part at random meaning I've now got 2 of the same item type on the processor which isn't what I'm looking to achieve. Part 'x' takes 16800 seconds to complete and part 'y' takes 3200. I've tried using zones in the process flow with subset constraints but i cant seem to get it working correctly. Any help would be appreciated. i want to make sure the processor doesn't pull a new item from the queue unless its finished with that set item type already.
For added context here is my attempt at this so far.
https://drive.google.com/file/d/1aQcX3nRDq2E1g0ixVnuwea9QDyeWj1w9/view?usp=sharing