Controlling the Processing of Derivation Steps (SAP Library

Controlling the Processing of Derivation Steps

Use

Normally, derivation steps are processed in the following way:

If you have defined a condition for performing a derivation step (see below), this is checked first. If the condition is not met, the step is not performed.
The system checks whether the source fields have values. If any of the source fields do not have a value, derivation is not performed.
If any of the target fields for this derivation step do not have values, the system executes the derivation step. If the system can calculate values, values are derived for all the target fields that are empty. The fields that already have values remain unchanged.
If the system cannot find suitable target values in this derivation step because of predefined source field values, none of the target fields are changed. No error message is issued.

This means that with the standard settings the account assignment derivation does not overwrite fields that already have values.

Features

You can use conditions and step and field attributes to control this standard method of processing derivation steps:

Conditions

For each derivation step, you can define a condition that must be met for the step to be executed on the Condition tab page. A condition consists of a number of subconditions that compare the account assignment values with constants.

Example

Example: You could stipulate that a step can only be executed if the company code is "1000". In this case, you would enter the following on the Condition tab page:

Name	Description	Operand	Value
COMPANY_CODE	Company code	=	1000

Step attributes

On the Attributes tab page, you can use the step attributes for each derivation step to control whether:

An error message is issued, if no target values are found
Processing of strategy is ended, if no values are found

For derivation types "Initialization" and "Move", this function is not available.

You can also make settings for "derivation rules" to allow expiration dates to be maintained for rule entries. If you activate this attribute, you can define a "valid from" date for your entries for a derivation rule.

Field attributes

You can determine field attributes by choosing for the source and target fields.

You can make settings to allow blank values for a source field. This means that derivation will still be performed, even if the given source field does not contain a value.
You can stipulate for a target field that:

The new value is not accepted if a value has already been taken from a previous derivation step
The new value is copied even if it is blank
The new value is copied, if it has a concrete value

This allows you to ensure that whatever the value determined by the derivation step, it is copied to the target field irrespective of whether the field already contains a value. After this derivation, you will not be able to overwrite this value manually.

Note

In previous releases, by making the relevant settings in Customizing (FM-CO assignment binding and FM-CO assignment binding), you were able to prevent the overwriting of FM account assignments derived by the system. From release 462, this Customizing setting is no longer available.

Apart from the "Derivation rule" derivation step, for source and target fields you can define that the complete field content or only part of the field content is included.