The table System_Variables can be used to store environment-specific information as this table cannot be promoted. As this is a special system table, values can be read very easy as a value for a JobDefinition's parameter.
{
# Default expression for parameter
=Variable.getString('SAP_SYSTEM')
}
In the above example, the value for 'SAP_SYSTEM' is read from the System_Variables table and is assigned as the default expression to the parameter.