Notice Pay Based on Length of Service
Depending on their length of service, you can decide on the notice pay. If they seek separation from the company within six months—or during the probation period—you need not collect notice pay. If the length of service is more than six months—or after the probation period—you have to ask them to give one month's notice or salary in lieu of the notice period.
Earned Leave (EL) in Factories
I have not heard that, in the factory, 2 days of EL are granted to employees for every 30 days worked. Anyway, depending on their service in the factory, you can give EL pro-rated to the number of days worked by them.