setup time in scheduling

hi all ,

i have a query , regarding setup time in Routing .

here base qty is 10 EA

setup : 10 MIN

machine : 60 MIN

when scheduling 20 EA then system is calculating :

setup : 10 MIN

machine : 120 min . But i want for 20 min setup time, that i can do it in scheduling formula .

BUt if i want to schedule for 5 EA qty then what to do ?

i know setup time is independent of lot size.

Regards