Example: Serialization - Defining the Send Sequence

You have the option of defining the sequence in which a process sends received messages. In doing so, you can specify that the process must wait for an acknowledgement from the receiver each time that it sends a message.

If the messages are sent from different business systems, it is only possible to serialize them by using an integration process. However, if the messages all come from just one business system, check whether it would not be better if this business system executes the serialization.

You can define a serialization in different ways. The following table shows the various options. You can find the examples in the Enterprise Services Repository under SAP Basis → SAP Basis <release number>, namespace http://sap.com/xi/XI/System/Patterns.

Serialization	Description	Example
Start Message	The process is started when a particular message is received	BpmPatternSerializeOneTrigger
Multiple Start Messages	Different messages can start the process	BpmPatternSerializeMultipleTrigger

Start Message

Three receive steps are defined in this example process. The corresponding messages are received in the container elements FirstMessage, SecondMessage, or ThirdMessage.

The process starts once the first receive step receives the message. For this reason, the Start Process indicator has been set for the first receive step. When a message is received, the receive step activates the correlation

Correlation

. This correlation is used by both subsequent receive steps and correlates the messages by means of an ID.

Note that you must ensure that the message of the first receive step - FirstMessage - really is the first message to arrive. If, for example, SecondMessagearrives first, it cannot be assigned to the process.

Once all three messages have been received, the process sends the messages in reverse order. Once it has sent a message, the process waits for the acknowledgment from the receiver to arrive before sending the next message.

All three abstract interfaces are used as inbound and outbound interfaces (more information: Process Signature ).

The following graphic illustrates the process definition:

Different Start Messages

Three receive steps are defined in this example process. The corresponding messages are received in the container elements FirstMessage, SecondMessage, or ThirdMessage.

Any of the three messages can start the process. For this reason, the Start Process indicator has been set for each of the receive steps. At design time it is not known which of the messages will arrive first. Therefore, the receive steps are arranged in a fork. If one of the receive step receives its message, it starts the process and activates the correlation

Correlation

. This correlation is used by both other receive steps. The fork should be complete once all three messages have been received. Therefore, the number of required branches is set to three.

Finally, the process sends the received messages in the specified sequence. Each send step waits for the corresponding acknowledgment once it has sent its message.

All three abstract interfaces are used as inbound and outbound interfaces (more information: Process Signature ).

The following graphic illustrates the process definition:

More Information:

Receive Step

Fork

Correlation: Defining Assignment of Messages to Process Instances