You must understand whether there are any significant changes in legislation already in place for your product, and whether you will implement these changes using multiple product periods.
Typically, for new products there is (to date) only a single version of the legislation, and so usually a new product will initially have only a single product period set up. Subsequent changes in legislation may occur once your product matures, of course.
See Handling Legislation Change for how to decide whether your product should have multiple product periods for legislation changes, or rules that branch based on legislation change. This will help you analyze how many periods your product is split up into.
Each product period will typically have its own special rule class for eligibility and entitlement calculations.
For a new benefit product created via the dynamic product wizard a default product period is automatically inserted and has a default eligibility and entitlement rule set associated with it. Although the default product period is published upon creation of the benefit product, the default eligibility and entitlement rule set is left in an in-edit state following completion of the dynamic product wizard. The rule set appears in the list of rule sets available for publication on the Cúram Express Rule Sets page of the Administration Workspace and is a generic rule set which is not suitable for product use prior to update. The rule set should be edited within the Cúram Express Rules editor to meet product requirements prior to use of the newly created product. See the section "Configuring the Product in the Administration Workspace" in the How to Build a Product Guide for additional information about new products created using the dynamic product wizard.