How to Configure and Determine a new Billing Plan Type

SAP Documentaton on Date Rules Billing Plan type

You first must decide if you want to create a milestone or Periodic Billing plan - if its milestone take a copy of plan type 40, if its periodic take a copy of plan type 02.Make the required adjustments to suit your business process.See below for screen shot of configuration:

Periodic Billing Plan Lines:

Milestone Billing Plan Lines:

The percentage field is only relevant for milestone billing as is the field Propose as Standard Line. In the Date proposal the period is not relevant for Milestone.

Customer Billing Plan Procedure:

The Billing plan procedure is relevant if you only want a billing plan determined for certain customers. The defined Billing Plan procedure can then be usedwhen assigning the Billing Plan Type to the Item Category or when assigning the Billint Plan type to the Transaction type (Periodic Billing Plan only). You define the procedureas below and then you assign this procedure to your Sold-to Party in transaction BP.

Assignment to Transaction Type (at Header level):

This is only applicable to Periodic Billing Plans - its primarily for ease of change of the Billing Request Items. Periodic billing plans can have many BRIs depending on the Horizon therefore it would be very time consuming to change for example the period length on all BRIs. This is where a header Billing plan can be used, all BRIs that are linked to the header will have the period changed if this is done at header. In the below screenshot you can see that a Billing Plan procedure is also assigned which means that only customer with Procedure 0002 in master data will have header billing plan type 02. Head billing plans are optional for Periodic Billing Plan.

Assignment to Item Category (at Item level):

If you want to use billing plans in a document then you must have a billing plan type determined at item level. You can choose to have the item billing plan linked to the header or not with the flag BiPl Itlevel only, of course this is only relevant if a header blling plan has been assigned to the transaction type.

Item Category Determination:

BRIs are a scaled down version of a normal line item. Therefore it is necessary to have an item category determined for the BRI. When the system generates billing request items, it uses the flow type, defined in the billing plan type, as the item category usage. The line item category in the document is used as the main item category.
In the configuration of the item category of the BRI the important data is in Pricing data the field Statist. Value and in Billng Data MilestoneBilling.

Date Profiles:

You need to assign date rules to you billing plan type so that dates can be determined automatically in the Billing Plan. For documentation on Date Rule
please see the following link
SAP Documentation on Date Rules