Hi Usha,
PMW is an alternative to the standard payment media print programs. you can use PMW in addition to standard payment media programs ( 60 Standard payment media programs).
You can convert each payment method individually to the PMW payment media formats. This means that you can use the standard payment media programs (RFFO*) and the new PMW payment media formats in the same system and even in the same payment run. so it is advisable to use both based on users requirement.