STO with 2 vendors for one plant

Question

Hello!
We are facing problems with stock transfer using transport order (STO). We want to use 2 different vendors for the same plant  (MK02 > Purchasing Data > Extras > Add.purchasing data). Some countries in our company should purchase from vendor X and others from vendor Y (X and Y is the same plant). The vendors have different settings.
Our problem is that SAP allows only one plant as vendor (table T001W-LIFNR). When we try to create a source list (ME01) for the vendor not in T001W-LIFNR we get the error message:
Vendor X and supplying plant PPPP incompatible
Message no. 06732
Diagnosis
You have entered vendor X and supplying plant PPPP in the source list. However, a different supplying plant has been assigned to vendor X in the master record.
Procedure
Enter either the vendor or the desired supplying plant.
Is works fine with the other vendor (the one defined for plant as vendor).
Has anybody an idea how we can solve this issue?
Thanks in advance and best regards
  Reinhard

Answer 1

Reinhard,
I think you may be confusing the purpose of a stock transport order.
The vendor assigned to the supplying plant is just another way to represent that plant.  Since there is only one plant, there can ONLY be one vendor.  In effect, plant = vendor.  One plant in your organization is 'buying' product from another plant in your organization.  One plant represents the 'customer', and one plant represents the 'vendor'. 
The vendor in the STO is totally unrelated to the vendor from which you originally bought the product.
Can you describe the business requirement which makes you think you need more than one vendor per supplying plant?
Rgds,
DB49