Comprehensive Guide to Activity Notation in BPMN: Key Concepts and Examples

Introduction to Activity Notation in BPMN

Business Process Model and Notation (BPMN) is a standardized graphical representation used to model business processes. Within BPMN, activities are central to defining the work performed within a process. This guide provides a comprehensive overview of activity notation in BPMN, including key concepts, types of activities, and examples to illustrate their use.

Key Concepts of Activity Notation

What is an Activity?

An activity in BPMN represents work that is performed within a business process. It is depicted as a rounded-corner rectangle and can be further categorized into tasks and sub-processes. Activities are essential for defining the sequence of work, assigning responsibilities, and specifying the flow of control within a process.

Types of Activities

BPMN distinguishes between two main types of activities:

1. Tasks: Represent atomic units of work that cannot be further broken down within the context of the process model.
2. Sub-Processes: Represent complex activities that can be broken down into smaller tasks or sub-processes.

Tasks

Tasks are the basic units of work in BPMN. They are depicted as rounded-corner rectangles and can be further classified based on their nature:

1. Task: A generic task that represents a single unit of work.
2. Send Task: Represents the action of sending a message to another participant.
3. Receive Task: Represents the action of receiving a message from another participant.
4. User Task: Represents a task that requires human interaction.
5. Manual Task: Represents a task that is performed manually, often outside the control of the process engine.
6. Business Rule Task: Represents a task that involves the application of business rules.
7. Script Task: Represents a task that involves the execution of a script.
8. Service Task: Represents a task that involves the invocation of a service.

Sub-Processes

Sub-processes are used to represent complex activities that can be broken down into smaller tasks or sub-processes. They are depicted as rounded-corner rectangles with a plus sign (+) inside. Sub-processes can be further classified based on their behavior:

1. Loop Sub-Process: Represents a sub-process that repeats multiple times.
2. Multi-Instance Sub-Process: Represents a sub-process that is executed multiple times in parallel.
3. Compensation Sub-Process: Represents a sub-process that is executed to compensate for a previous activity.
4. Ad-Hoc Sub-Process: Represents a sub-process where the tasks can be executed in any order.
5. Compensation and Ad-Hoc Sub-Process: Combines the characteristics of compensation and ad-hoc sub-processes.

Call Activity

A call activity is a special type of activity that represents the invocation of a reusable sub-process. It is depicted as a rounded-corner rectangle with a bold outline. Call activities are used to modularize and reuse sub-processes within a process model.

Examples of Activity Notation

The provided BPMN (Business Process Model and Notation) diagram illustrates a process for handling orders, specifically focusing on the availability of articles, procurement, and customer communication. Below is a detailed explanation and interpretation of the diagram:

Overview

The diagram outlines the steps involved in processing an order, from receiving the order to either shipping the article or handling cases where the article is not available. It includes decision points, tasks, events, and gateways to manage the flow of the process.

Detailed Explanation

1. Order Received

• Event: The process begins with the event “Order Received,” represented by a circle with an envelope icon. This indicates that an order has been received, triggering the process.

2. Check Availability

• Task: The first task is “Check Availability,” represented by a rounded-corner rectangle. This task involves verifying whether the ordered article is available in stock.

3. Decision Point: Article Available?

• Gateway: The process then reaches a decision point, represented by a diamond shape. This gateway evaluates whether the article is available.

If Article is Available:

• Sequence Flow: If the article is available, the process follows the “Yes” path.
• Task: The next task is “Ship Article,” represented by a rounded-corner rectangle. This task involves shipping the article to the customer.
• Task: Following the shipment, the task “Financial Settlement” is performed, represented by a rounded-corner rectangle with a dollar sign icon. This task involves processing the payment for the order.
• Event: The process concludes with the event “Payment Received,” represented by a circle with a red border. This indicates that the payment has been successfully received, marking the end of the process.

If Article is Not Available:

• Sequence Flow: If the article is not available, the process follows the “No” path.
• Sub-Process: The sub-process “Procurement” is initiated, represented by a rounded-corner rectangle with a plus sign (+) inside. This sub-process involves procuring the article from a supplier.

4. Procurement Sub-Process

• Tasks and Events within Procurement:
  • Task: The procurement sub-process includes tasks such as placing an order with the supplier and managing the delivery.
  • Events: The sub-process handles events like “Undeliverable” and “Late Delivery,” represented by circles with icons.

If Undeliverable or Late Delivery:

• Sequence Flow: If the article is undeliverable or there is a late delivery, the process follows the respective paths.
• Task: The task “Inform Customer” is performed, represented by a rounded-corner rectangle. This task involves notifying the customer about the issue.
• Event: The process concludes with the event “Customer Informed,” represented by a circle with a red border. This indicates that the customer has been informed, marking the end of the process.

If Article is Successfully Procured:

• Sequence Flow: If the article is successfully procured, the process continues.
• Task: The task “Inform Customer” is performed, represented by a rounded-corner rectangle. This task involves notifying the customer that the article is now available.
• Task: The task “Remove Article from Catalogue” is performed, represented by a rounded-corner rectangle. This task involves removing the article from the catalogue if it is no longer available for order.
• Event: The process concludes with the event “Article Removed,” represented by a circle with a red border. This indicates that the article has been removed from the catalogue, marking the end of the process.

Interpretation

The BPMN diagram effectively models the order processing workflow, highlighting the key activities, decisions, and events involved. It provides a clear visual representation of the process, making it easier to understand and manage. The diagram helps in identifying potential bottlenecks, such as procurement delays, and ensures that appropriate actions are taken to inform customers and manage the catalogue.

Conclusion

Activity notation in BPMN is a fundamental aspect of modeling business processes. By understanding the different types of activities and their uses, you can create clear and effective process models that accurately represent the work performed within your organization. Whether you are modeling simple tasks or complex sub-processes, BPMN provides the tools and notation to capture the essence of your business processes. This BPMN diagram is a valuable tool for businesses to streamline their order processing workflow. By clearly defining the steps and decision points, it helps in improving efficiency, enhancing communication, and ensuring customer satisfaction. The use of standardized BPMN notation makes the diagram accessible to both technical and non-technical stakeholders, facilitating better collaboration and process improvement.

BPMN References