How to Manage Work Orders and Task Cards in a Modern MRO

In an aviation maintenance organisation, the work order is the basic unit of work. Everything goes through it: the scope the customer requests, the tasks technicians perform, the material consumed, the hours booked and the final certification. When the work order is well managed, operations flow. When it is not, delays, invoicing errors and audit findings follow.

In this article we walk through the life cycle of a work order, explain the role of task cards, and look at how to ensure traceability with digital sign-offs.

Work order and task card: what each one is

• Work order (WO): the container for the work. It identifies the customer, the aircraft, engine or component, the requested scope, the dates and the status. It is also the basis for cost control and invoicing.
• Task card: the specific work instruction. It describes what must be done, with which maintenance data, which tools and materials are needed, and which sign-offs are required. A work order contains one or many task cards.

An A-check may have dozens of task cards. A heavy check or an engine shop visit may have hundreds or thousands.

The work order life cycle

1. Reception

Everything starts with a customer request. In aircraft maintenance, it usually comes from the operator's CAMO as a work package. In component or engine MRO, it arrives with the physical unit and its documentation.

At this stage, the team checks:

• That the work is within the organisation's approved scope.
• That current, applicable maintenance data is available.
• That the customer information is complete: serial number, hours and cycles, relevant history and, for components, the reason for removal.
• For components, the incoming inspection: physical condition, incoming documentation and unit registration.

An incomplete reception causes many problems later. Missing data now becomes waiting time later.

2. Planning

With a clear scope, the planning team prepares the work:

• Generates task cards from maintenance data or approved templates.
• Estimates hours per task and per trade.
• Identifies the required materials and reserves or requests them.
• Assigns tools with valid calibration.
• Schedules execution based on staff capacity and available space (hangar, ramp or workshop).

Planning does not end here. During execution, every finding forces replanning.

3. Execution

Technicians perform the task cards. At each step they record:

• The work performed and measured values (clearances, torque values, readings).
• The tools used.
• The materials consumed, with their traceability.
• The hours spent.
• Execution sign-offs and, where required, independent inspection sign-offs.

If the technician finds an unexpected defect, they raise a non-routine card (NRC), described below.

4. Inspection and technical close-out

Before certification, the team verifies that:

• All task cards are complete and signed.
• NRCs are resolved or, where appropriate, deferred according to approved procedures and with the customer's agreement.
• No tools are still outstanding. Tool control at close-out is key to preventing items being left in the aircraft (FOD).
• Installed material has its conformity documentation.

5. Certification

Authorised certifying staff issue the relevant certificate:

• A CRS (Certificate of Release to Service) for work on aircraft.
• An EASA Form 1 or an FAA Form 8130-3 for components and engines, depending on the applicable regulatory framework.

After certification, the work order moves to administrative close-out: invoicing, record archiving and analysis of deviations between estimated and actual figures.

Routine and non-routine task cards

Routine task cards

These are the planned tasks. They come from the maintenance programme, airworthiness directives, service bulletins or the customer's request. They are known before work starts, can be estimated and can be prepared in advance.

Non-routine cards (NRCs)

NRCs record work that arises during execution. For example:

• Corrosion found during a structural inspection.
• A part worn beyond limits.
• Previously unreported damage.
• A failure detected during a functional test.

Each NRC should include:

1. A description of the finding, ideally with photos and a precise location.
2. A reference to the originating task card, showing how it was found.
3. Corrective action based on approved maintenance data.
4. An estimate of hours and material.
5. Customer approval, where the contract requires it.
6. Sign-offs for execution, inspection and closure.

NRCs are critical for two reasons. First, safety: a poorly documented or unclosed finding is a risk. Second, business: NRCs often account for a very significant share of hours on heavy checks, and they are the main source of schedule and cost deviations. If they are not recorded properly, they are not invoiced properly.

Traceability: the backbone of maintenance

In aviation, traceability is not an extra. It is a requirement. In any audit or investigation, the organisation must be able to answer these questions:

• Who performed the work and who inspected it?
• Was that person authorised for that task?
• Which maintenance data was used, and at which revision?
• Which tools were used, and were they calibrated?
• Which parts were installed, with which serial number and which certificate?
• When was each step carried out?

With paper, answering means searching through filing cabinets and trusting that everything was transcribed correctly. With a digital system, the answer is a query.

Digital sign-offs: what makes them work

A sign-off on a task card is not a formality. It is a statement that the work has been done according to approved data. That is why a digital sign-off must meet certain conditions:

• Unambiguous identification of the signatory, with personal, non-transferable credentials.
• Authorisation check at the moment of signing: the system must confirm that the person holds a valid authorisation for that task, type and category.
• A reliable timestamp.
• Integrity: after signing, the record cannot be changed without leaving a trace. Any correction must be recorded as such.
• Retention of the record for the required period, with backups.

In addition, the use of electronic records and signatures must be described in the organisation's procedures (the MOE under EASA, the repair station manual under the FAA) and accepted by the competent authority.

Compliance: how it all fits together

Good practices to get started

1. Standardise your task card templates before digitalising. Digitalising a mess does not fix it.
2. Define a clear NRC workflow, including customer approval.
3. Load staff and authorisation data carefully. They are the foundation of sign-offs.
4. Train technicians in real conditions, next to the aircraft or at the workshop bench.
5. Review your MOE procedures to reflect the new process.

Conclusion

The work order and its task cards are the living record of an MRO's work. Managing them well means better planning, fewer execution errors, invoicing for the work actually done and passing audits with clear evidence. Digitalisation, with well-designed sign-offs and traceability, turns that record into an operational advantage.

SkyPlannerHub is a cloud ERP for aviation maintenance organisations: line maintenance, base maintenance, and component and engine MRO. If you want to review how you manage your work orders and task cards today, get in touch with us.