The Scheduling Engine

The scheduling engine is the logic tool that creates plans based on your operational data.

It is responsible for assigning all required tasks to visits which are then assigned to your tracks.

Scheduling Process

The scheduling engine:

  1. Calculates the optimal schedule date for each task based on aircraft usage information and maximum task yield.

  2. Combines tasks into visits based on automerge, extraction and check hierarchy rules.

  3. Assigns visits to tracks according to location capabilities, applying the execution strategies listed below.

  4. Any visits that cannot be assigned are placed into overflow.

Scheduling Goals and Execution

The scheduling engine creates plans based on the following goals:

  • Maximize yield

    • Optimal schedule dates are calculated for each task.

    • Automerging combines visits within the task yield ranges.

  • Optimize ground time for each aircraft

    • The scheduling engine minimizes the number of visits required by applying check hierarchy and automerging rules.

    • Check hierarchy rules may override the yield ranges of smaller checks in favor of including smaller tasks with parent tasks.

    • Extraction rules can provide additional constraints to the scheduling engine by allowing a range of aircraft to be out of service at any given time for specific tracks or task types.

  • Reduce the amount of manual scheduling

    • Visits with the longest span are scheduled first to maximize the number of visits assigned to each track, and limit the number of visits placed in overflow.

    • Visits whose span would include a blackout day are moved ahead of the blackout day or placed on another track.

    • Visits whose span includes non-working days are extended to compensate for the number of non-working days.

    • Aircraft retirement is known and managed.

    • Check hierarchy rules are applied so that smaller tasks and checks are automatically included in larger checks where appropriate.

    • Automerge rules are applied so visits within pre-defined proximity will combine into a single visit, and scheduled at an ideal location based on yield considerations for all checks in the visit.

    • Track applicability is respected to ensure visits are placed on tracks that have the capability to complete the included tasks and checks.

Scheduling Requirements

In order to create a plan, the scheduling engine MUST have the following operational data:

  • Fleet Details

  • Task Definition

  • Task Applicability

  • Forecast Model

  • Location Capability

Providing additional data (Last Done, Automerge Rules, Check Hierarchy Rules, Extraction Rules) will improve the accuracy of forecasted due dates and help maximize task yield. It will generally reduce the amount of manual work required, as well as minimize the ground time required to complete the required aircraft maintenance program.

Scheduling constraints order of precedence

The scheduling engine will consider various constraints when placing visits on tracks. It will use the following precedence order for constraints found in the operational data of the plan:

  1. Avoid placing visits that would result in Max Extraction Rules violations
  2. Track priority (lower number means higher priority, higher priority gets precedence)
  3. Task type priority
  4. Start date (the one that has the latest start date is given precedence because it maximizes the yield)
  5. Travel leading and trailing days (the lower one is given precedence)
  6. Fewest calendar days - Minimizes the ground time of the aircraft, which depends on the Track's non-working days and proficiency factor.
  7. Default check (this is the last resort for the tie breaker if all the above conditions are the same between the 2 positions. it will sort based on the track id)