Maintenance programmes

The Maintenance programmes module defines the what and the when of preventive maintenance. Three objects work together:

  • The AEP fixes the target structure.
  • One or more PEAs gather the maintenance programmes applicable to an aircraft type or a fleet.
  • Each PRE defines a precise maintenance cycle: how often, on which component, against which criterion.

Anatomy of a PRE

Components of a maintenance programme

  1. Scope

    Target PN or AEP family. A PRE can apply to a container (“M88 engine”) or to a specific sub-module (“combustion chamber”).

  2. Trigger criterion

    Calendar (every 12 months), counter (every 600 hours, every 200 cycles), or composite (whichever comes first).

  3. Expected operations

    Ordered list of tasks to perform, usually referenced in the manufacturer’s S1000D documentation. Each operation may carry a standard duration (in minutes) entered at the PRE level (manufacturer reference); it is propagated automatically to derived PEAs at instantiation and will serve as the basis for estimating the workload of a work package.

  4. Tolerance

    Margin allowed beyond the limit (e.g. +5 % or +20 hours) before strict block. Past the tolerance, the aircraft is grounded.

The scheduler

A background job recomputes active limits for every aircraft and module. It crosses:

  • the current CA;
  • counters (hours, cycles, specific measurements);
  • PREs relevant to the installed modules.

Overdue limits surface in the work packages list, where they become candidates to be folded into a WP.

PRE lifecycle

PRE lifecycle

  1. Creation

    Initial definition via POST/maintenance-programmes, in draft.

  2. Validation

    Reviewed by the CAMO. A validated PRE triggers the computation of limits across the impacted fleet.

  3. Evolution

    A new version may be published. Active limits follow the transition rules defined in the PRE.

  4. Retirement

    A retired PRE no longer generates new limits. Already open limits remain active until closed via a WP.

Duplicating a PRE into a new revision

Rather than editing a PRE that is in service, you publish a new revision: a full copy you work on, leaving the original revision untouched until the new one is validated.

Create the next revision of a PRE

  1. 1. Start the duplication

    From the PRE list (Duplicate button) or from the PRE detail page (Duplicate button, top right).

  2. 2. Confirm the revision

    The system suggests a “next” revision (A → B, 2024.1 → 2024.2…), which you are free to edit. It must differ from the current revision and must not already exist for that code.

  3. 3. Work on the copy

    The copy carries over code, name, scope, notes and the whole task tree (operations, triggers, materials). It starts in Planned status, with no effective date or authority, and stays linked to the source revision (a “↩ Revision of a previous PRE” link appears on its page).

Duplication does not touch the source PRE nor the PEAs that attach it: it is a new, independent reference programme that you validate and then attach to PEAs once it is ready.

Attaching and syncing a PRE to a PEA

A PEA inherits the content of its attached PREs. On attachment, the system copies the PRE’s tasks (with their operations, triggers and materials) into the PEA. That copy is not live: if you later edit the PRE — for example by adding an operation to one of its tasks — the PEA does not update on its own. This is deliberate: no change to the reference programme should silently alter a plan in production.

To carry the PRE’s additions into the PEA, the user triggers the sync explicitly.

Carry an operation added to a PRE into a PEA

  1. 1. Open the PEA

    Maintenance plans → click the relevant PEA.

  2. 2. 'Attached PREs' section

    At the bottom of the sheet, find the row for the PRE you just edited.

  3. 3. Click 'Synchronise'

    The Synchronise button copies the PRE’s additions into the PEA: new tasks, operations, triggers and materials added on the PRE side. A message confirms the detail (“Sync OK — 1 operation added”).

The sync is additive and non-destructive: it adds what is missing (matched by source identifier) but never overwrites your local PEA edits and never removes items you may have deleted from the PRE. For fine-grained syncing of an operation’s materials (with a diff preview), see PRE → PEA BOM.

Technician view

On the aircraft sheet, the Limits panel lists every active PRE with its remaining potential (“47 hours until next visit”, “3 cycles until inspection”). See also

Maintenance plans for the definition of the expected operations.