serial number

hi.

i make confirmation mfbf with serial number.

now the problem is. when i make backflush of 1st assembly with serial number 'x'.after i make backflush of 2nd assembly with same serial number 'x'.system allowing to confirm. is there any option to put lock????

1st and 2nd assembly are different material number

becaz we produce material with mixed production in a single line. system should not allow the serial number, if that serial number is already exit, even for any other assembly.

thx in advance