Picking base UOM among hierarchy of UOMs

Hi Gurus:

My client does not have to do anything with 'Base UOM.' However, to create a material in SAP, I believe Base UOM is mandatory.

My client product source system has four levels of measurement hierarchy. All the four levels are need to be maintained in SAP. We took the lowest level as Base UOM. To maintain the other 3 levels in alaternate UOMs, the conversion factor is going beyond 5 digits.

Materials in SAP are created/updated with Interface (standard MATMAS IDoc) through SAP PI.

Let's say for Eg: SH, BX, PK, CA are four levels from source system with following conversion -

1 CA = 10 PK = 10 BX = 1000 SH;

which means as 1 BX = 1000 SH; 1 PK = 10 BX; 1 CA = 10 BX.

since we have chosen lowest level as Base UOM, this conversion from source system is converted to Base UOM (conversion is done by SAP PI) as follows -

1 BX = 1000 SH; 1 PK = 10000 SH; 1 CA = 100000 SH.

I am not able to maintain "CA" as alternate UOM because, the numerator (UMREZ) is more than 5 digits.

I have looked at SAP NOTE - 362932. One of their recommendations is to solve the above issue is 'pick higher level as base UOM.'

In the above scenario, interface has to check number of digits of conversion factor and see if it is greater than 5 digits. If yes, then pick the next level as Base UOM. (If SH is chosen as Base UOM, then 1 CA = 100000 SH, then interface has to come to next lower level and check number of digits. Now, it is 1 PK = 10000 SH. Then system should pick BX as base UOM).

As creation/updation process is happening through interface, can you please suggest an enhancement place to put this logic or any other way to get it done through the interface?

Your suggestions are highly appreciated.

Thanks & Regards,

KC.