In the unlikely event that your initial version of product requires multiple product periods (i.e. already has changes of legislation and/or policy to deal with), first work with a single product period only, starting at the start of your overall product, and with no end date. Further product periods can be implemented when this initial product period is up-and-running. A default product period and associated eligibility and entitlement rule set is automatically created and published for a benefit product that is created via the dynamic product wizard. This eligibility and entitlement rule set is intended to be edited in line with your product requirements prior to product use.
When you have implementations for your single product period up-and-running, then you can split your product into multiple product periods, cloning your rule sets from the first period you implemented, as a starting point.