MRP-Planned Orders and Make vs. Buy

Hi,

We have items that are set up as purchased but on occasion, we can manufacture internally.  We have an issue that although it appears that supply/demand is correctly capturing the supply generated from a work order, we are still getting a planned message to buy and therefore creating the potential for excess inventory.  Is there a way to get the system to recognize the supply from work orders when it's set up as a procured item?

Promise   Date	Demand	Supply	Quantity Available	Order No	Type	Branch/ Plant
12/1/2015	171	171		222	On Hand Balance
12/2/2015	238	409	928362	WD	222	FIRM MAKE ORDER
12/2/2015	209.44	618.44	OP	222	EXTERNAL VENDOR PLANNED ORDER