Time Phase Inquiry

Can anyone tell me what calculation is used to determine when a receipt should occur in time phase?
We have a part that Time phase is saying has a receipt that is past due. Our Min OH is 1800 and we have 4950 on hand with upcoming requirements totaling 3362 parts the last requirement date of 10-22-2018 (1139 parts). We have a 1 day lead time and have a lot multiple of 1800. With all this in place, we feel we should not have to run the parts until 10-21-2018. What are we missing in our calculation?
Does the Costing Lot size impact the calculation?

Any input / suggestions are welcome.
Thanks all.

See screenshot

Costing Lot size does not impact Time Phase.

However if you take the MRP job out, you go below min on 10/22. To demonstrate, delete the late MRP job and rerun the Time Phase and you will see what happens. As to the timing of the MRP job, I can’t answer that. The must be something like receive time or something like that to cause the receipt so far ahead.


Thank you Charlie…. I will have the schedulers look into that.