The system supports four ways to decide when a maintenance activity is due:

Relative triggers are based on how much has changed since the last service (for example, every 500 hours of use or every 90 days since the last visit).
Absolute triggers are based on fixed milestones from when the asset first went into service (for example, at 1,000 hours and again at 2,000 hours).
Date Recurrence triggers are based on a calendar schedule (for example, every October 1st or every 90 days from a fixed start date).
Whatever Comes First uses both a usage-based rule and a calendar rule and picks whichever date arrives sooner.

Each maintenance activity can also have an active window—for example, "only apply this between 500 and 5,000 hours" or "only during the first two years." Once an activity moves outside its active window, it stops generating work orders automatically.

Due dates recalculate whenever conditions change: you edit the plan, time passes, or new service meter unit (SMU) readings are logged. This means connected or IoT devices that write usage data directly to the asset's service meter log automatically feed into maintenance plans and keep projected due dates current without manual intervention. If you need to set a specific date manually, you can override the calculated value at any time.

This feature isn't enabled automatically. To use it, create a maintenance plan, add at least one maintenance activity, and configure a trigger type. Due dates begin calculating once the plan is applied to an asset. To stop generating work orders for an activity, remove the activity from the plan or move the asset outside the active window.