eventstimer triggerVariant of Start Event

Timer Start Event

A Timer Start Event launches a process automatically at a scheduled time, after a delay, or on a recurring cycle. It eliminates manual triggers for time-driven workflows like daily reports, monthly billing, or periodic maintenance tasks.

Category
events
Type
start
BPMN Spec
Section 10.4.2
Icon Class
bpmn-icon-start-event-timer

What is a Timer Start Event?

A Timer Start Event automatically starts a new process instance based on a time condition. It can fire at a specific date/time, after a defined duration, or on a recurring schedule using ISO 8601 timer expressions (e.g., cron-like cycles).

Visual Representation

The Timer Start Event is shown as a thin circle (indicating a start event) containing a clock icon. The clock symbol distinguishes it from other start events and signals that the process is triggered by time rather than a message, signal, or manual action.

Key Characteristics

  • Three timer types: Supports specific date (timeDate), duration (timeDuration), and recurring cycle (timeCycle) expressions
  • Automatic instantiation: Creates new process instances without user or system interaction
  • ISO 8601 expressions: Uses standardized time notation for portability across BPMN engines
  • Top-level processes only: Cannot be used inside sub-processes; use Timer Intermediate Catch Events for mid-process delays

Common Use Cases

Scheduled Report Generation

A daily or weekly reporting process starts automatically at a set time to compile data, generate reports, and distribute them to stakeholders.

Recurring Billing Cycle

A monthly billing process is triggered on the first of each month to calculate charges, generate invoices, and initiate payment collection.

Periodic System Maintenance

A nightly maintenance process starts at off-peak hours to perform database cleanup, cache invalidation, and health checks.

Frequently Asked Questions

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