Modeling Message Flow in BPMN: A Step-by-Step Guide to Visualizing Interactions

Business Process Model and Notation (BPMN) is a powerful graphical representation for specifying business processes in a workflow. One of its key features is the ability to model messages exchanged between participants, which is crucial for understanding interactions in a process. This tutorial will explain how to define and visualize message flows using BPMN.

Key Concepts

1. Message Flow: Represents the flow of messages between two participants (e.g., between a customer and a sales clerk). It is depicted as a dashed arrow with an envelope icon.
2. Participants: Entities that interact in a process. In BPMN, participants are represented as pools, which can further be divided into lanes for more detailed roles.
3. Message Events: These are events that represent the sending or receiving of messages. They can be start events, intermediate events, or end events.

Example Scenario

Let’s consider a simple scenario where a Customer makes a request to a Sales Clerk, and the Sales Clerk provides feedback.

Step-by-Step Tutorial

1. Define Participants

• Customer Pool: Represents the customer who initiates the request.
• Sales Clerk Pool: Represents the sales clerk who receives the request and provides feedback.

2. Create the BPMN Diagram

• Create Pools and Lanes:
  • Draw two pools labeled “Customer” and “Sales Clerk.”
• Add Activities:
  • Customer Pool:
    • Make Request: An activity where the customer initiates a request.
    • Receive Feedback: An activity where the customer receives feedback from the sales clerk.
  • Sales Clerk Pool:
    • Receive Request: An activity where the sales clerk receives the customer’s request.
    • Give Feedback: An activity where the sales clerk provides feedback to the customer.

3. Define Message Flows

• From Customer to Sales Clerk:
  • Draw a dashed arrow (message flow) from Make Request in the Customer pool to Receive Request in the Sales Clerk pool.
  • Label this message flow as Request.
• From Sales Clerk to Customer:
  • Draw another dashed arrow from Give Feedback in the Sales Clerk pool to Receive Feedback in the Customer pool.
  • Label this message flow as Feedback.

4. Visual Representation

Here is a simple representation of the BPMN diagram:

Explanation of the Diagram

• Make Request: The customer initiates the process by making a request, which is sent as a message to the sales clerk.
• Receive Request: The sales clerk receives the request and processes it.
• Give Feedback: After processing, the sales clerk provides feedback.
• Receive Feedback: The customer receives the feedback.

Conclusion

Modeling message flows in BPMN helps to clarify the interactions between different participants in a process. By visualizing these flows, organizations can better understand their workflows, identify potential bottlenecks, and improve communication among stakeholders. This example illustrates a straightforward message exchange, but BPMN can handle much more complex interactions in larger processes.