Scheduling tasks or task chains
To schedule a new task into a plan, or if there are changes to a task definition and you want future instances the task to use the modified task definition or drop the task, you can run the scheduling logic for a task or task chain on any plan that includes the task. When scheduling tasks, you need to understand how the logic works and the impacts on visit span.
When you schedule a task or task chain, you can specify the schedule start date for today (default) or in the future. You cannot schedule a task to start earlier than today's date. No changes are made to the plan before the schedule start date that you specify. For example, a scheduled task uses the revised name and description from the task definition, starting on the task's schedule start date.
If the task is part of a task chain, then the scheduling logic runs on the entire chain. When scheduling a task chain, you can only select the Task ID of the first task in the chain. If the task is not part of a chain, then the scheduling logic runs on the individual task.
If the task is overdue on the date selected as the schedule start date, then the task is scheduled to a visit in overflow starting on the selected schedule start date. The task will be visible as overdue on the Gantt chart.
- The new task is added to existing visits (on or before the due date.)
- New visits (on or before the due date) are added to open slots on a track that can perform the task.
- A new visit is added on OVERFLOW.
You can add new tasks to locked visits, but locked instances of the task being scheduled are not re-scheduled or removed unless that task is no longer applicable to the aircraft.
No change to visit span for check hierarchy
When the scheduling engine adds a task to a visit to satisfy a check hierarchy rule, the destination visit's span is not increased.
Automerge can increase span
For an automerge rule where the source task has a larger span than the destination task, scheduling by task does not change the visit title to the task with the largest span.
When the automerge rule has a Visit Span of ADD, a task that's automerged to an existing visit adds span.
The scheduling engine first tries to extend the end of the visit. If this scheduling attempt overlaps into an adjacent visit or blackout period, then the engine attempts to extend the start of the visit. If neither extension is possible without overlapping another visit, then the end of the visit is extended, creating overlap. No adjacent visits are moved.
The span of a visit does not increase if its current span is greater than or equal to the span of the largest span task in the visit plus the span of the task being scheduled. If the current span of the visit is less than this, then it is increased by the span of the task being scheduled.
Task overdue for aircraft with a retirement date
When you schedule an overdue task for an aircraft with retirement date, if the aircraft's retirement date is before today's date, the task is not scheduled.
If the retirement date is after today, but before the selected schedule start date, the task is scheduled (overdue) to start on its scheduled start date.
Non-working days
Increasing the span of a visit may mean overlapping additional non-working days (NWDs) on the track. The span will be increased to account for the NWDs.
Removing a task from a plan
Do not delete task definitions from operational data if instances of that task are in any plan. Instead, remove all of the task's applicability rules from operational data, and then perform Schedule Task (schedule start date: today) on that task in all affected plans. This removes future instances of that task from those plans. If you don't know whether a task is in a specific plan, you can download the CSV file for the plan and filter for the task.
Reserved (child) plans
Schedule Task can be run on a reserved (child) plan. The engine will re-run the scheduling logic against all applicable aircraft, not just the aircraft in your reserved subfleets. Note that only changes to your reserved subfleets are merged back to the master plan.