Business Process Model and Notation (BPMN) is a graphical representation used for specifying business processes in a workflow. BPMN provides a standardized way to model business processes, making it easier to understand, analyze, and improve these processes. This tutorial will use a case study based on the attached image to explain the key concepts of business process modeling.

Case Study: Patient Appointment and Prescription Process

The Figure below illustrates a business process involving a patient, a doctor, and a doctor’s office. The process includes scheduling an appointment, handling symptoms, and prescribing medication. We will use this case study to explain the key BPMN concepts.

Key BPMN Concepts

1. Pools and Lanes

Pools: Represent major participants in a business process. In our case study, there are two pools: “Patient” and “Dr. Office.”
Lanes: Sub-divisions within a pool that represent different roles or departments. In the “Dr. Office” pool, there are no explicit lanes, but the tasks are performed by the doctor’s office staff.

2. Events

Start Event: Represented by a circle, it indicates the beginning of a process. In our case study, the start events are the patient’s request to see the doctor and the doctor’s office receiving the request.
End Event: Represented by a circle with a bold outline, it indicates the end of a process. In our case study, the end events are the patient receiving the prescription and the doctor’s office sending the prescription.
Intermediate Events: Represented by a circle with a double outline, they indicate something that happens between the start and end events. In our case study, intermediate events include sending and receiving messages between the patient and the doctor’s office.

3. Activities

Tasks: Represented by rounded rectangles, they indicate a single unit of work. In our case study, tasks include “Send Doctor Request,” “Receive Appt.,” “Send Symptoms,” “Receive Prescription,” “Patient Dr. Request,” “Patient Schedule Appt.,” “Patient Handle Symptoms,” “Patient Handle Prescription,” “Receive Doctor Request,” “Send Appt.,” “Receive Symptoms,” and “Send Prescription.”
Sub-Processes: Represented by a rectangle with a plus sign, they indicate a process that can be broken down into smaller tasks. In our case study, there are no explicit sub-processes, but the tasks can be considered as part of a larger sub-process.

4. Gateways

Gateways: Represented by a diamond shape, they control the flow of the process based on conditions. In our case study, there are no explicit gateways, but the flow of tasks and events can be considered as conditional based on the patient’s actions and the doctor’s office responses.

5. Flow Objects

Sequence Flow: Represented by solid arrows, they indicate the order of activities. In our case study, the sequence flow shows the order of tasks and events, such as the patient sending a doctor request, the doctor’s office receiving the request, and so on.
Message Flow: Represented by dashed arrows, they indicate the flow of messages between pools. In our case study, the message flow shows the communication between the patient and the doctor’s office, such as sending and receiving appointment confirmations, symptoms, and prescriptions.

Case Study Analysis

Patient Pool

Start Event: The patient wants to see the doctor.
Task: “Send Doctor Request” – The patient sends a request to see the doctor.
Intermediate Event: The patient receives an appointment confirmation.
Task: “Send Symptoms” – The patient sends their symptoms to the doctor’s office.
Intermediate Event: The patient receives a prescription.
End Event: The process ends with the patient handling the prescription.

Dr. Office Pool

Start Event: The doctor’s office receives the patient’s request.
Task: “Receive Doctor Request” – The doctor’s office receives the patient’s request.
Task: “Send Appt.” – The doctor’s office sends an appointment confirmation to the patient.
Intermediate Event: The doctor’s office receives the patient’s symptoms.
Task: “Send Prescription” – The doctor’s office sends a prescription to the patient.
End Event: The process ends with the doctor’s office sending the prescription.

Message Flow

The patient sends a doctor request to the doctor’s office.
The doctor’s office sends an appointment confirmation to the patient.
The patient sends their symptoms to the doctor’s office.
The doctor’s office sends a prescription to the patient.

UML vs. BPMN: Understanding the Differences

Unified Modeling Language (UML) and Business Process Model and Notation (BPMN) are both essential modeling languages used in the fields of software development and business process management. While they share some similarities, they serve distinct purposes and are optimized for different applications. Here’s a detailed comparison of UML and BPMN.

1. Purpose and Focus

UML (Unified Modeling Language)

Focus: Primarily used for software engineering and system design.
Purpose: Provides a standardized way to visualize the design of a system, covering various aspects such as structure, behavior, and interactions among components.
Use Cases: Commonly utilized in object-oriented software development, including class diagrams, sequence diagrams, use case diagrams, and state diagrams.

BPMN (Business Process Model and Notation)

Focus: Specifically designed for business process modeling.
Purpose: Provides a graphical representation of business processes that is easily understandable by all stakeholders, including business analysts, managers, and technical teams.
Use Cases: Used for mapping out business workflows, analyzing processes, and identifying areas for improvement.

2. Diagram Types

UML

Common Diagrams:
- Class Diagrams: Show the structure of a system by illustrating classes and their relationships.
- Sequence Diagrams: Represent the interaction between objects in a time-sequenced manner.
- Use Case Diagrams: Depict the functional requirements of a system and the interactions between users (actors) and the system.
- State Diagrams: Illustrate the states of an object and transitions between those states.

BPMN

Common Diagrams:
- Business Process Diagrams (BPDs): Show the flow of activities and decisions in a business process.
- Collaboration Diagrams: Illustrate interactions between different participants (e.g., departments or organizations).
- Choreography Diagrams: Focus on the message exchanges between participants in a process.

3. Notation and Symbols

UML

Complex Notation: UML uses a variety of symbols and notations that can be complex and may require training to understand. Each diagram type has its own set of symbols.
Flexibility: UML is highly flexible and can be adapted to different methodologies, including Agile and Waterfall.

BPMN

Standardized Notation: BPMN has a standardized set of symbols that are easy to understand, making it accessible to non-technical stakeholders.
Clear Representation: The symbols represent different elements like tasks, events, gateways (decisions), and flows, making it straightforward to visualize processes.

4. Stakeholder Communication

UML

Technical Audience: Primarily aimed at developers, architects, and technical teams. It may not be easily understood by non-technical stakeholders.
Detailed Specifications: Provides a detailed view of the system for technical implementation but may lack clarity for broader business discussions.

BPMN

Business-Oriented: Designed for use by business analysts and stakeholders, in addition to technical teams. The clear visual representation helps facilitate communication across different levels of the organization.
Focus on Processes: Emphasizes understanding and improving business processes, making it valuable for process improvement initiatives.

5. Tools and Software Support

Both UML and BPMN have a variety of modeling tools available, many of which support both notations. Popular software tools include:

Visual Paradigm: Offers comprehensive support for both UML and BPMN, making it an ideal choice for teams working on software development and business process modeling.

Conclusion

BPMN is a powerful tool for modeling business processes. By using the key concepts of pools, lanes, events, activities, gateways, and flow objects, you can create clear and concise diagrams that represent complex business processes. The case study of the patient appointment and prescription process illustrates how BPMN can be used to model a real-world scenario, making it easier to understand, analyze, and improve the process.

In summary, UML and BPMN are both valuable modeling languages, but they serve different purposes. UML is focused on software design and system architecture, while BPMN is tailored for visualizing and improving business processes. Understanding the differences between these two notations will help organizations choose the right tools and approaches for their specific needs. For teams looking to integrate both software development and process management, tools like Visual Paradigm provide a comprehensive solution that supports both UML and BPMN.