Discovering the Business Process Engine Architecture

In the business process engine extension, SAP Commerce Cloud supports the modeling, execution, management, and monitoring of business processes. But what exactly is a business process?

To illustrate this concept, consider this typical example. A customer places an order on an online shop, and this activates a series of subsequent steps, as illustrated.

This process consists of five essential steps:​

1. The customer's credit card is validated for expiration date, credit limit, and potential fraudulent activity.​
2. After the credit card is verified, the payment is processed.​
3. If the payment is approved, the warehouse receives a notification to prepare and dispatch the ordered item to the customer.​
4. The next step involves awaiting confirmation from the warehouse that the item has been dispatched.​
5. Finally, the customer is informed about their credit card validation status or the dispatch status of their ordered item.

To support this process, a lightweight XML file, also known as Process Definition XML file in SAP Commerce Cloud, is implemented. This XML describes the process using nodes and transitions, where:​

• nodes signify the steps involved such as "Credit Card Check" or "Capture Payment"
• transitions, on the other hand, define the outgoing link to the next node that is to be invoked in the process.​

Be aware that a typical Business Process Management (BPM) tool is not suitable for defining a Process Definition XML file. How to go about defining such a file will be comprehensively discussed in the upcoming lesson. As of now, we'll operate under the assumption that the process has already been implemented in the XML file, and we'll explore what comes next.

The Business Process Management module in the Platform supports the ability to implement and interpret a Process Definition XML file, which is used to describe a business process. The module is supported by a Process Engine that can load these XML files and initiate business processes accordingly. To understand its operative principles, refer to the following diagram. Let's examine the area each number represents.

Let's examine the meaning of each number.

1. A Process Definition XML file consists of nodes and transitions that connect these nodes. Within each node, there may be a reference to an action that contains the business logic to be carried out. This logic may also utilize any Services defined in the service layer of SAP Commerce Cloud. For example, in the earlier process, the "Credit Card Check" node might engage the cardService to validate a given credit card.
2. Upon startup of SAP Commerce Cloud, Process Definition XML files are read into the Process Engine and later used to create business processes.
3. A related business process is initiated when a trigger, such as the placing of an order, is detected. As per the process definition, the corresponding actions are converted into tasks in the task queue. These tasks are then processed sequentially according to the predefined order of the business process.

We'll delve into the complex features of the business process support structure in the upcoming lessons. You'll learn how to create a Process Definition XML file, initiate a business process using the XML, and monitor the processes.