Hi Luis,
My issue is not yet resolved , as a temporary solution , I used some calculated columns and manually put in some conversion factors when I had one or two UoMs to be converted .
On other hand if had many UoMs I used a table with base UoM , expected UoM and conversion factor . In my case I was working on Material Master tables so I had MARM table which had UoM conversions in the form of numerator and denominator values, so I had written a SQL query on MARM to get the final data into format of conversion factor. Do let me know if that sql query can be of any help to you.
Reg: Client Number:
Even though you are not connected to ECC tables , the mandatory tables (T006 , T006D and T006 A ) for UoM conversion will have the MANDT as its fetched from the source system , if you inserted some dummy values instead of extracting them from ECC , please try inserting the dummy MANDT as well and maintain the same in the calculated column.