Comprehensive Guide to BPMN Diagram Types

Business Process Modeling Notation (BPMN) is a powerful tool for illustrating business processes in a diagrammatic form. It is widely used to communicate a variety of information to different stakeholders, often involving multiple organizations or companies. BPMN supports three main categories of processes: Orchestration, Choreography, and Collaboration. This guide will provide an in-depth look at each type of BPMN diagram, their purposes, and how they are used.

1. Orchestration Process

Definition

An orchestration process is a standard process in BPMN that typically models a single coordinating point of view. It describes a process within a single business entity and is contained within a Pool. This type of process usually has a well-formed context and is the most commonly encountered in BPMN diagrams.

Characteristics

• Single Coordinating Point of View: Focuses on the internal processes of one business entity.
• Well-formed Context: Clearly defined start and end points.
• Contained within a Pool: Represents the boundaries of the business entity.

Example

A typical orchestration process might involve a series of tasks within a company, such as order processing, where each task is performed by different departments within the same organization.

2. Choreography Process

Definition

A choreography process is a new model type introduced in BPMN 2.0. It focuses on the interaction between participants and concentrates on the message flow instead of the individual detailed tasks of a process. Choreography diagrams do not belong to any pool and are used to define how individual processes interact with each other.

Characteristics

• Interaction Between Participants: Shows the message flow between different business entities.
• No Pool: Does not belong to any specific pool; focuses on between-process interactions.
• Choreography Tasks: Consists of tasks that define messages between participants.

Example

A choreography diagram might illustrate the interaction between a manufacturer and a customer in a sales order process. The customer places an order, and the manufacturer confirms it, with each step involving message exchanges between the two parties.

Choreography Tasks

• Initiating and Non-initiating Participants: Each task involves at least two participants, with one initiating the interaction.
• Message Definition: Messages between participants are defined within the task.
• Visual Representation: The initiating participant is shown in the same color as the task, while the non-initiating participant is in gray.

3. Collaboration Process

Definition

A collaboration process depicts the interactions between two or more business entities. These interactions are defined as a sequence of activities that represent the message exchange patterns between the entities involved. A collaboration diagram is recognized by the presence of more than one Pool.

Characteristics

• Multiple Pools: Shows the message flow between different business entities.
• Interaction Sequence: Defines the sequence of activities and message exchanges.
• Black Box or Detailed Process: Pools may be empty, a black box, or show a detailed process within.

Example

A collaboration process might involve a purchasing scenario where a customer interacts with a retailer and a transporter. Each entity has its own internal processes, but the collaboration diagram focuses on the message exchanges between them.

Public vs Private Process

Private (Internal) Processes

• Detailed Process Flow: Shows the detailed process flow for each partner.
• Internal Focus: Concentrates on the internal processes within a single organization.

Public Processes

• Inter-organizational Cooperation: Describes the interaction among different organizations.
• Black Box: Treats the internal processes of partners as “black boxes.”
• Information Exchange: Specifies the information and objects exchanged between partners.

BPMN Conversation Diagrams

Definition

BPMN Conversation diagrams, introduced in BPMN 2.0, provide a high-level view of the communications between participants. They do not include process logic and focus on the conversations between the participants without showing the individual message flow.

Characteristics

• High-level View: Shows the overall communications between parties.
• Conversation Node Elements: Represented by hexagons.
• Conversation Link: Represented by double lines.

Example

The Conversation model in the Figure below is a representation of the communications or messages between the participating roles shown in the Choreography model in the Figure on the example 2 above. The Conversation model in this case depicts a overview of the overall communications between the parties. Nevertheless it does not shows the sequence of the communications as that shown in a Choreography model.

Conclusion

BPMN diagrams are essential tools for modeling business processes, and understanding the different types—Orchestration, Choreography, and Collaboration—is crucial for effective process management. Each type serves a specific purpose and provides a unique perspective on business processes, making BPMN a versatile and powerful tool for business process modeling.