The cart refresh process is designed to:

Reset the pricing of all items on the cart to the current prices in the PDM. For example, if a package sku was added and it had a price override along with an upgrade, the price would reset, the upgrade sku will be maintained. PDM price changes will also be recognized so the updated price is reflected in the cart. A la carte skus will simply be reset to the current PDM sale price.

This program just displays what would change and can be used for QA/Testing. The final production process will be run nightly on carts older than 14 days up to 90 days*.