Planual rules regarding production lists.

Don't set all lists to Production Data initially. Setting a list back to Structural (after a synchronize) will remove data from the existing Production list even if the members are the same.

You can't hard-code a reference to an item in a production data list because that member may be deleted by an end user.

Only lists that need to be amended as part of the business process, or where imports populate the lists, should be set to Production Data lists.

Review the Referenced by column of potential lists and check for hard-coded formula references before checking them as Production data so you don't create rollbacks.