Transit Time - FSM Upload

Summary:
I'm using FSM Import and Export Option to upload the Transit time between Supplier Address (IE-SA) to other Internal Location (IL). and i have succussed for load some of the records. then I'm facing some issues.
For Import and export option we must load 2 CSV files.
Parent file we are populating Supplier Name & Supplier Address and Location Code.
But our Child file we are populating only Supplier Address and Location code.
As per our business Scenario 1 Supplier site is associated with lot of suppliers. so, while we load the data, I'm getting error as Duplicate key data was found in file WSH_TRANSIT_TIME.csv and skipped this supplier.