routing

Hi Gurus,

My client business process is like this,

after production last operation ,colouring will happen for steel pipe.

in routing ,i have mainted activity types , right now all the things ok.

some times when operator doing coating (colouring ),due to some problem again he have to do colouring may be two times or three times.

but we cannot change always base quantity ,because when we have to do colouring two times or three times we dont know,bcz if color is not done properly again we have to do.

how can i do this scnario.