White Paper: A more efficient maintenance data standard

Author: Iryna Khomenko, Manager, Operational Efficiency, IATA TechOps

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Iryna Khomenko, Manager, Operational Efficiency, IATA TechOps shares the reasons for and the development of a new Scheduled Maintenance Data Standard (SMDS)

The underlying theme of this article is a paradigm change for the approach to creating and performing the control and oversight of an airline or operator’s maintenance program. These new standards mean that things will be done differently for operators, MRO IT companies and OEMs (original equipment manufacturers). However, little if anything will change with regard to the oversight authority. The biggest change for them will be in approving a maintenance program because it’s an approved document in Europe but not in North America. The majority of civil aviation authorities (CAAs) will be doing that in a harmonized structured data format because, for an application of this standard, there is not only PDF or paper documents scanned or created in a PDF format and sent to any CAA.

THE REASONS THAT DRIVE THE CHANGE

Several issues suggested that there was a need for the project. Principal among them was that there are many sources that feed into the maintenance planning process and the maintenance planning document (MPD) (figure 1) but those inputs all work to different timetables.

As the figure shows, the various inputs are documents produced by OEMs and by the national authorities, and they all feed into the maintenance program. The problem with these documents is that they all need to be updated but that they also are all stand-alone documents, each of which has their own revision cycle. The upshot is that the operator needs to review the requirements for scheduled maintenance regularly to ensure that change is incorporated into the aircraft maintenance program. It is a challenge to control all of this and there is a risk that something could be overlooked. As a result of this, as can be seen on the top of figure 1, an operator could miss a requirement with that being compounded by the different revision cycles so that, by the time they catch up with this missed requirement, the compliance deadline will have been passed making them out of compliance.

An example of what could result if a requirement is missed

Imagine 3 MPD revisions/ 2 MRBR (Maintenance Review Board Report) revision/ 2 ALI (Airworthiness Limitation Items) documents per year (figure 2).

It’s not only that MPD, MRBR and ALI need to be revised, scheduled documents need to be updated and tell users when to do the work. There is another group of documents, AMM, CMM, EMM, IPC and other materials, which describe the procedure. These documents tell users how to do the work and also have their own revision cycles.

The other problem has been that, where different documents are published regarding a particular task, those documents will also have different schedules for completion of that task. MRBR will have one interval for the task while the Critical Design document will have a different interval. These documents need to be revised to their individual schedules plus procedure documents have to also be updated. All documents affected by a change will have to have implemented that change by the deadline set for the change or they’ll be out of compliance.

As IP93 states, “The aircraft operators are faced with multiple documents defining mandated and recommended maintenance tasks. Incorporating these tasks into the operator and OEM maintenance specifications is confusing, labour intensive, and extremely prone to error. Maintaining getting authority approval for the various documents is a burden for the manufacturers as well.”

In addition to aligning the varied revision schedules, different documents are also in a variety of formats such as PDF, Excel and Text as well as XML (figure 3). These various file formats and different contents between document-types, different OEMs and aircraft types mean that there are no common standards to process document revisions on the operator’s side. In addition, various documents are available in PDF only and require manual transfer to the operators IT System.

To handle this workload within the regulatory timescales requires a team handling ICA (Instructions for Continued Airworthiness) revision incorporation. The challenges described above increase the risk of errors. There are cases where three simultaneous revisions of ICAs in three various documents revise the same task and all of them are different; a complete confusion for the airline or operator and giving rise to examples of incorrect Never Exceed Period (Interval) incorporation into manuals as a direct result.

FROM THE OLD TO THE NEW

… it sometimes happened in the past that due dates of source documents’ compliance times were earlier than the subsequent MPD Revision. The illustration on the left of the figure shows the airworthiness limitation document coming out, then the MPD has to catch up but, while the MPD is being updated, the ALI compliance deadline has arrived. The requirement then has to be included in the next MPD revision.

From IP93, “Documents such as ALI/AWL, MRB, and CMR are issued out of phase with MPD. The majority of operators use the MPD to base their programs on and the authorities also usually require close, if not strict compliance with the MPD. With compliance required for ALI/AWL, MRB and CMR, operators are struggling to update their programs without MPD revisions. Operators are required to review multiple sets of documents for the same task revisions. “

To meet the approved documents’ (MRB, CMR, ALI, etc.) compliance time, operators have to process source document revisions without waiting for the next MPD. These source documents do not contain the full set of data, required to complete a maintenance task (e.g., Zones, Panels, AMM-reference, etc.). Consequently, the missing data have to be investigated by the operators (with the risk of errors) and have to be validated after MPD publication. The result is a chain reaction and it was to prevent that which was why IATA started this project.

The idea and the goal is to have one data module representing one task, and this task will not change its form and content through all documents, where it is presented (MRBR, Critical Design Configuration Control Limitations (CDCCL), ALI, MPD, etc). Not, as was the case before, that if only one task is revised, the whole document has to be updated. With this new system, it will only be necessary to update the data module in order for all the documents that contain this data module to get updated. The update will be tracked by the data module, not by the document.

And so, users might read the maintenance requirement as a data module: one maintenance requirement, one task. If the revision is coming up, it revises one by one without dragging the whole document with it. In short, all changes are notified within the single system regardless of their source.

If the data module originates from the MRBR, that means that this data module will be revised and all adjacent places where the task in question might be, are also revised at the same time; the airline does not need to carry out the revision on each and every document where it is applicable, or wait to make sure that it is in compliance with each of these documents. It’s just the data module, everything has to be updated to comply with the updated data module task.

A SINGLE SOURCE OF THE TRUTH

This initiative is also implementing the principle of the single source, the single repository, and the traceability of the maintenance requirement. IATA is working on a system to allow for push or pull notifications. So, consider if the maintenance requirement document is from an OEM and the recipient is also in the system with that OEM, or there is some other sort of electronic communication between OEM and operator. Where this system sends a notification to the operator saying ‘this task or this data module has been updated’, through the OEM publications notifications system, this update gets into the maintenance information system (MIS / ERP) as an upgrade and is further used for the production of the maintenance planning package.

There is no need for an operator to go through the documents replacing document by document. It also eliminates a lot of human error as well as simplifying the maintenance planning process. In the old process, specific programs have to be run that will search for the task, take information, such as labor hours, from the task into the maintenance planning system and calculate productivity and how many people are needed for the maintenance. In the new process, the data module will feed directly to the maintenance information system and there is no need to run any programs to pull that information in. All this is the work of the MRO IT system to do that, to combine it and to make this feeding-in seamless.

CONSIDERATIONS FOR THE REGULATOR

For the regulators, there are two areas that should be considered. The first area is ‘how the maintenance requirement is created’.

There, the whole chain is viewed when it starts with the MSG-3 (Maintenance Steering Group-3) process that is reviewing new maintenance tasks; the process of revision and conclusion on whether this task is adequate to what it is intended to do and the specification. Then the maintenance requirement goes through revisions and is approved by MRB. Next, it becomes an MRB (Maintenance Review Board) task. Airworthiness Limitation maintenance requirement is created in a different process.

That part of the chain, in the view of IATA, will not change with the proposed new standard, because the principles on which the creation of the task is based, are not influenced by this standard in its the core. IATA believes that this part of the process remains intact. Therefore, little if any changes for the regulatory authority.

However, where it does change is with the tools and means of approval of a maintenance requirement. With the old system, in some regulatory authorities, paper documents were still circulating; but it is known that, in the last ten years, there has been a move to PDFs which are signed electronically before sending. It is the whole maintenance program that has been signed. However, now there will be no need for the whole document being sent to the regulatory authority, IATA proposes that just the data module containing the changes needs to be sent to that authority and signed digitally either with a digital or electronic signature. Which the authority chooses will depend on many factors such as how advanced their national government system is, what kind of digital signature is approved with them; IATA cannot dictate that.

In the past there was a practice of issuing Temporary Revisions (TR). The problem with that is that, when there is a temporary revision, it is more difficult to control because it may become out of synchronization with procedure documents. Also, it’s very difficult to manage because, in one year, you can receive multiple revisions, so you need to keep them in sight and not lose any of them. The new standard makes the handling of such TRs easier.

Additionally, operators still need to go to their local regulatory authority to approve the maintenance program. This maintenance program may also contain optional tasks. So, the maintenance program, as it shapes up, incorporates requirements from very basic and mandatory to recommended tasks and tasks related to the climate of operation, configuration of the aircraft and business requirements of the operator. At the end there will be a pretty large pot of requirements that the operator needs to manage and, at least if this new standard is in place, it should make the lives of the maintenance planners easier.

So, again, two areas for the regulatory authority; one is not affected and, for the other one, the suggestion is that regulatory authorities pursue digitalization as much as possible to enable this new way of interacting with the OEMs and operators.

This standard also will decrease the chance of operators running out of compliance, it will make the traceability of the maintenance requirements from OEM to operators easier, and eliminate human errors in the processing of scheduled maintenance data.

How this new Scheduled Maintenance Data Standard (SMDS) will operate can be seen in figure 5 below.

The XML S1000BR standard itself, owned and held by the ATA e-Business program, was published in November 2021 and can be viewed on their website. It is available for a fee to operators that are not members and is free to ATA member companies. It is not a work from scratch: the XML S1000D for civil aviation existed before for a couple of decades and is what certain OEMs were already using for their maintenance program creation. However, those programs used the generic civil aviation version of S1000D standard, and that version had a lot of discrepancies and a lot of issues, particularly for scheduled maintenance data. Therefore, it was decided, using the civil aviation standard, to pick the business rules that would satisfy the requirements of the SMDS and then to modify those that can be modified, some cannot, to accommodate the SMDS. There are two things to understand: although the standard was published only in November 2021, the implementation has been underway for more than five years, C Series has been delivered using this data standard, and so now this published standard has been given an extra boost for OEMs and, hopefully, a start to move it from OEMs and regulatory authorities to operators and MRO IT companies. Previously, OEMs used the civil aviation part of S1000D; now it is hope they will use a more convenient or appropriate set of business rules of S1000D which is SMDS which will be better for MRO IT companies and operators.

TIMETABLE FOR IMPLEMENTATION OF THIS CHANGE

With respect to the timeline, there are not yet the commitments from the OEMs as to implementations on the large scale however there are already developments. Because of the pandemic, some have suspended their research and development programs. What is known is that this SMDS standard is absolutely in OEMs’ plans for a gradual transition. There is no time commitment from each OEM for when they will be able to say that ‘this aircraft program’ is one hundred percent SMDS compliant but there is a commitment that a gradual transition will be made.

On the operators and MRO IT side, IATA has had a couple of meetings. Operators want MRO IT companies to implement the new standard but the MRO IT companies are waiting for the ‘push’ from their customers.

IATA would like to increase awareness about this new standard and encourage the adoption among all interested parties, on the manufacturing as well as aftermarket side.

NEXT STEPS FOR IATA

Now that the SMDS is ready, this year’s task for IATA is to produce an IATA SMDS manual. That manual will be a ‘how to do’ instruction for the larger audience. So, this new manual will cover some business applications of the SMDS, some of the approaches, and differences between the OEMs. The manual will aim at helping operators to engage with SMDS in addition to having XML schemas in S1000BR and S1000D.

Some comments from the industry

Comments from some of the people who have contributed to the development of a more efficient maintenance data standard, on what they thought were the benefits to be gained from implementing the new Scheduled Maintenance Data Standard (SMDS).

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As interest in Civil Aviation usage of S1000D has grown, it is essential to retain the benefits of our industry’s decades-long history of technical data standardization. As such, the ATA e-Business Program publishes ATA Spec 1000BR, Civil Aviation Business Rules for S1000D, to provide a baseline level of standardization for implementation of S1000D in the worldwide Civil Aviation industry. To extend that principle, in 2021 the ATA Technical Data Working Group, in partnership with experts from the IATA SMDS working group, added business and technical usage rules to Spec 1000BR for the exchange of Scheduled Maintenance Data between Civil Aviation manufacturers and operators.

Paul F. Conn

Director, Electronic Data Standards

ATA e-Business Program

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The S1000D standard was selected at the beginning of the A220 program to develop the maintenance technical publications. With the introduction of the data module (DM) concept, data management and revision control are done at the publication level as well as the task level. All revisions of DMs are stored in a common source database. Regulatory approvals are currently obtained at the level of the publication module (PM).

Irina BALOI

Head of Maintenance Publications and Authoring, ABSSM1

A220 Maintenance Engineering

Airbus Canada

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“Currently Airbus Commercial Aircraft publishes scheduled maintenance data in line with S1000D standards for the two most recent aircraft programs, the A220 and the A350.
Airbus actively promotes the modular, task-centric approach targeted by SMDS group in the creation, management and publication of scheduled maintenance data – as opposed to the rather rigid document centric approach.

The goal is to improve the way we manage data in the industry, in all stages and involving all stakeholders.

Airbus commits to the task centric modular approach for scheduled maintenance through a large-scale internal transformation project, in collaboration with our customers, business partners and airworthiness authorities.”

Ferdinand Hermann SASS

Maintenance Data Program Manager

Customer Services – SIMEB

AIRBUS

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The standard for scheduled maintenance data is really important for operators as there exist many different documentation types and definitions around this in the industry. We have been working a long time with IATA, manufacturers and regulators on a common standard and it will enable us to have better control when uploading data to our current compliance control system software.

It is important to have standards across all aircraft types and OEM types, and whilst we have lived with differing approaches and definitions for the same type of task for many years it will help in the training of Maintenance programs specialist and other professionals within the industry.

A common standard for these instructions for continued airworthiness is a definite benefit for the future.

Wayne Thompson

CAMO Manager

British Airways Safety and Security

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A common data format standard… reduces the complexity and increases the robustness of import loaders; supports incremental task-based revisions instead of document-based revisions; and creates the opportunity to get access to task updates via webservice. It is a pre-condition for a single source philosophy which helps to avoid conflicting/overlapping OEM requirements; improves consistency between MPD and MPD sources and ensures faultless content-transfer to the MPD; results in a harmonized task-numbering between MPD and its sources; and eliminates the need to cross-check the AMP against MPD and its sources.

Armin Bayer

Lufthansa

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Embraer is planning to implement S1000D standard for new projects and the importance to use Scheduled Maintenance Data Standard (SMDS) is to be aligned with industry standards towards improving data exchange between OEMs, operators and regulatory authorities. SMDS will standardize formats, sources, contents to help operators avoid confusions when they are creating/managing their Maintenance Program (MP). This will mitigate potential human errors throughout the process.

We also expect to have MRB process improvements in terms of data approval when we consider modulars contents to be summitted, managed and published.

Carlos Augusto Teixeira

Contributor’s Details

Iryna Khomenko

Iryna Khomenko is a Manager of Operational Efficiency in IATA with 14 years’ experience in Aircraft Operations including, for the last six years, being responsible for development and progress for several projects within the Digital Aircraft Operations Initiative. Before joining IATA Iryna worked at Aerosvit Airlines in Ukraine for six years, having started her career in Ukrainian — Mediterranean Airlines after she had obtained her master’s degree in Management and Economics.

IATA

The International Air Transport Association (IATA) is the trade association for the world’s airlines, representing some 290 airlines or 82% of total air traffic. IATA supports many areas of aviation activity and helps to formulate industry policy on critical aviation issues. Over more than 75 years, IATA has developed global commercial standards upon which the air transport industry is built. The aim is to assist airlines by simplifying processes and increasing passenger convenience while reducing costs and improving efficiency.