The parameter TestRun is used in write BAPIs, for example, Create() or CreateFromData(), to check the entries for the object instance in the database before actually creating the object instance. The generation of the instance, for example, creating master data, is only simulated and the data is not written to the database.

To simulate the creation of the object instance and to supply the relevant return messages, the BAPI should carry out all the necessary checks (excluding technical checks, such as, establishing the connection to the R/3 System), without actually updating the database.

Updating can be switched on or off using the TestRun parameter. The parameter is based on the data element TESTRUN. This can have the following values:

• ' ' (no value)

• 'X'

Keep in mind the following as you are programming:

• Do not assign any internal numbers either for the object itself, or for any dependent objects (for example, EAN numbers or Mat.Ledger No. in the material master).
• Be careful when calling function modules in other applications as these could assign numbers or update the database.
• Do not inadvertently write change documents.
• Create a message in the return parameter of the BAPI that informs users whether the BAPI has been implemented in simulation mode.