Output Determination for Billing Documents
The following figure outlines output determination for billing documents:

In SAP S/4HANA, SAP S/4HANA Output Management is used for billing documents as default. However, it is possible to enable the NAST approach again by setting a specific Customizing parameter (for more information, see SAP Note 2267376).
The SAP S/4HANA Output Management framework is the strategic output management framework in SAP S/4HANA and future developments will only be made in this framework. Adobe XFA is the default technology for form templates delivered within this framework, but legacy forms (SAPscript, SmartForms, Adobe Forms) are still supported. The main benefits of the new approach are the following:
Extensibility: Broad usage of CDS views
BRFplus: Flexible and powerful output parameter determination
Unified solution across the applications: SD, MM, FIN, and so on
SAP Fiori: Full integration with SAP Fiori apps
State-of-the-art e-mail support: Flexible configuration, multiple recipients, and e-mail templates
In contrast to the output management based on NAST, the new output management supports only the print, e-mail, XML, and IDoc (for on premise) channels. Other channels are not available by default.
Decision Tables
The following figure outlines a decision table:

Decision tables consist primarily of rows and columns. The columns are further divided into condition columns and result columns.
Decision tables are used to determine the different output parameters (output type, receiver, form template, and so on).
When a decision table expression is called, every row is processed in sequence. In each row, every condition column cell is processed from left to right. If the condition in each input column cell of a row is met, the field values defined in the result columns are returned. It is possible to enter expressions or direct values in these cells. It is possible to evaluate the values in each cell by using comparison operators, value ranges, and patterns.
Decision Tables for Output Determination
The following figure shows an example of decision tables for output determination:

Using decision tables, you can control the determination of the output type, receiver, channel, printer settings, and form template for billing documents. The table rows can be rearranged so that the most specific conditions are tested first. Tables can also be exported and imported to and from Microsoft Excel.