RevenueStory, being a subscription analytics platform, offers multiple reports that require working with the subscriptions' historical data. When you sign up with Chargebee with no subscription data, then the history of each subscription entry is captured right from the beginning. However, when you sign up and import your past subscriptions into Chargebee, RevenueStory will only be able to capture the history of subscriptions that happens from the initial sync time. To fix this gap, MRR History Builder is created in Chargebee. 

The goal of MRR History Builder is to generate historical data for each subscription from its first activation date to the initial sync date. Historical data is captured by scanning the subscriptions' associated invoice line items imported into Chargebee.