Validation and Substitution

Validation(OB28)


A validation rule is basically a check on a certain field's data. When a user is entering a transaction and enters data in that certain field which violates the validation rule, a error message appears for the user and generally will not allow the transaction to continue. The functional analyst designs the validation rule in one of several transactions. You can set them up to be called at the Document Header level, at the Line Item level.
These checks are created in transaction GGB0 and activated for FI in transaction OB28

Substitution(OBBH)

The substitution rule also checks a certain field's data (that you design in configuration). If the field's data matches what has been configured in the substitution rule, the data will be removed. Then specific other data will be substituted into that field. Substitutions can also be set up at the header, line item, or complete document level, and if a certain set of user-defined criteria are met, then a new value is put into a specific field. For instance, if Company = X and Cost Center = Y, then change Profit Center to be Z. It doesn't work on all fields, but can come in handy for Profit Centers or Allocations, and sometimes Texts such as SGTXT.

Substitutions are set up using GGB1 transaction and are activated in FI using transaction OBBH.