How do you align events with the process flow and the level of detail in BPMN?

1 Why events matter

Events are essential to capture the dynamic and complex nature of business processes. They show how the process responds to external or internal stimuli, how it produces outcomes or messages, and how it handles errors or exceptions. Events can also influence the sequence, timing, and branching of the process flow, as well as the allocation of resources and responsibilities. Therefore, choosing the right type and level of events can make your BPMN diagrams more accurate, clear, and meaningful.

2 How to choose event types

BPMN defines three main types of events: start, intermediate, and end events. Start events mark the beginning of a process or a subprocess, and can be triggered by a message, a timer, a signal, or a condition. Intermediate events occur between the start and the end of a process or a subprocess, and can be used to model delays, timeouts, escalations, compensations, or cancellations. End events mark the completion of a process or a subprocess, and can indicate the type of result, such as a message, a signal, an error, or a termination. Each event type has a different shape and symbol to distinguish it from the others.

3 How to align events with process flow

To align events with the process flow, you need to consider how they connect with other elements, such as activities, gateways, and flows. Events can be attached to activities or gateways to indicate boundary events, which are events that affect the execution of a specific element. For example, a timer boundary event can show that an activity has a deadline, or an error boundary event can show that an activity can generate an exception. Events can also be connected by flows to indicate throw and catch events, which are events that send or receive messages or signals between different parts of the process. For example, a message throw event can show that an activity sends a notification to another process, or a signal catch event can show that an activity waits for a signal from another process.

4 How to choose level of detail

The level of detail of events depends on the purpose and scope of your BPMN diagram. You can use different levels of abstraction to represent events, such as none, basic, descriptive, or analytical. None means that you do not include any events in your diagram, which is suitable for very high-level or simple processes. Basic means that you use only the event type and shape, without any additional information, which is suitable for general or overview processes. Descriptive means that you add some details to the events, such as names, labels, or attributes, which is suitable for detailed or specific processes. Analytical means that you use all the available features and options for events, such as subtypes, markers, or parameters, which is suitable for complex or technical processes.

5 How to use event subtypes

BPMN offers several subtypes for each event type, which can help you refine and clarify your events. For example, start events can have subtypes such as none, message, timer, signal, conditional, link, error, escalation, compensation, multiple, parallel multiple, or terminate. Each subtype has a different meaning and implication for the process flow. For example, a none start event means that the process starts without any trigger, a message start event means that the process starts when a message is received, and a timer start event means that the process starts at a specific time or after a certain interval. Each subtype also has a different marker inside the event shape to indicate its nature.

7 Here’s what else to consider

This is a space to share examples, stories, or insights that don’t fit into any of the previous sections. What else would you like to add?