traceability for WM
After MIGO, system generate a GR number(goods reciept number) which is same to material document number. The GR number can be display in quant with LS23. But material staging from warehouse to PSA, the quant and GR number in WH storage bin will be change to PSA's quant. The GR number is also changed. If production line return the material from PSA to WH, the GR number from system is not original one. So it will have some problem if we want to return it to vendor. Because with GR number, we will know the relevant PO number.
Please advise how to solve the problem.