Aftermarket Digital Control Systems and Maintenance Monopoly Risks in Europe

1. Introduction

Aftermarket Digital Control Systems are increasingly important in aircraft, industrial machinery, vehicles, energy systems, medical equipment and other technologically complex products.

A modern product may be sold initially by one manufacturer but remain dependent on that manufacturer for:

diagnostic software;

electronic control units;

firmware;

software updates;

authentication keys;

calibration tools;

technical data;

cloud-based monitoring;

cybersecurity certificates;

spare parts;

repair authorisation;

maintenance records;

remote diagnostics.

This creates a potential aftermarket monopoly.

The basic economic structure is:

Original equipment sale → Installed customer base → Digital control system → Data/software dependency → Spare parts + maintenance → Long-term aftermarket power

The important legal question is not simply whether the manufacturer has a large share of the original equipment market. The question is whether, after customers have become locked into the installed system, the manufacturer obtains a dominant position in a separate aftermarket and abuses that position.

European competition law has recognised this issue for decades. In Hugin, the Court accepted that a manufacturer could have a dominant position in the market for its own spare parts even though the primary equipment market was competitive. (Eur-Lex)

2. What Is an Aftermarket Digital Control System?

A digital control system may include:

electronic controllers;

embedded software;

diagnostic interfaces;

proprietary communication protocols;

cloud platforms;

remote monitoring;

authentication systems;

firmware;

digital twins;

predictive-maintenance software;

encrypted maintenance data;

calibration software.

For example:

Aircraft manufacturer

↓

Digital flight-control/engine-control system

↓

Aircraft remains operational for 20–30 years

↓

Operator needs software + diagnostics + parts + maintenance

The manufacturer may therefore continue controlling an important part of the customer's economic relationship long after the original sale.

3. What Is an Aftermarket Monopoly?

An aftermarket monopoly exists where a supplier obtains substantial or dominant market power over after-sales products or services associated with an installed primary product.

Examples:

spare parts;

software licences;

diagnostic tools;

maintenance;

firmware updates;

technical information;

repair authorisation;

cybersecurity certificates.

Simple example

Suppose an airline purchases an aircraft from Company A.

After five years:

Company A controls the diagnostic software;

only Company A can issue authentication certificates;

only Company A has access to repair codes;

independent MRO companies cannot access technical data;

replacement components require Company A's software approval.

The airline may technically be free to choose another maintenance provider, but practical switching may be extremely difficult.

That is the central aftermarket competition problem.

4. Why Digitalisation Makes the Problem More Serious

Traditional aftermarket control involved:

Physical spare parts.

Digital aftermarket control can involve:

Software + data + authentication + interoperability + cloud access + physical parts.

This creates several additional barriers.

A. Software lock-in

The independent repairer may have the necessary physical part but cannot activate it without proprietary software.

B. Data lock-in

The manufacturer may hold historical diagnostic information.

C. Authentication lock-in

Only the OEM may possess the cryptographic keys needed to authorise repairs.

D. Cloud dependency

A physical machine may depend on a remote server controlled by the manufacturer.

E. Update dependency

A repair may require a firmware update available only from the OEM.

5. Relevant Market Definition

The first question is:

Is the aftermarket part of the primary market, or is it a separate relevant market?

Possible markets include:

market for original equipment;

market for spare parts;

market for repair services;

market for diagnostic software;

market for technical information;

market for firmware updates;

market for digital maintenance services.

The answer depends on facts.

Important factors include:

switching costs;

compatibility;

customer expectations;

lifecycle;

availability of alternatives;

price of the primary product;

availability of independent repair;

technical restrictions.

6. Case Law 1 — Hugin

Hugin Kassaregister AB and Hugin Cash Registers Ltd v Commission

Case 22/78, Court of Justice, 31 May 1979

This is one of the most important aftermarket cases.

Hugin manufactured cash registers and controlled the supply of spare parts for its machines.

It refused to supply spare parts to independent maintenance company Liptons.

The Court recognised a separate relevant market for Hugin spare parts required by independent repair and maintenance companies. Hugin had a dominant position because competing sources of supply were not realistically sufficient. (Eur-Lex)

Principle

A manufacturer does not necessarily escape dominance merely because its market for the original equipment is competitive.

It may have dominance over:

its own specialised spare parts.

Digital application

The same reasoning can potentially apply to:

proprietary diagnostic software;

firmware;

authentication credentials;

digital repair tools;

specialised electronic modules.

7. Case Law 2 — Volvo v Veng

AB Volvo v Erik Veng (UK) Ltd

Case 238/87, Court of Justice, 5 October 1988

Volvo concerned spare parts for motor vehicles and intellectual-property rights.

The Court considered whether a dominant manufacturer could refuse to supply certain protected spare parts to an independent repairer.

The judgment is important because it established that the exercise of an intellectual-property right can, in exceptional circumstances, constitute abuse of dominance.

Relevance

A manufacturer cannot simply argue:

“The software is proprietary, therefore competition law cannot apply.”

The interaction between:

IP rights + dominance + aftermarket access

must be considered.

Digital application

The principle can become relevant to:

proprietary diagnostic software;

copyrighted repair software;

protected technical interfaces;

patented control-system components.

8. Case Law 3 — Magill

RTE and ITP v Commission / Magill

Joined Cases C-241/91 P and C-242/91 P, Court of Justice, 6 April 1995

Magill concerned copyright-protected television programme information.

The Court recognised exceptional circumstances in which refusal to license protected information could constitute abuse.

The case is important because it established a restrictive framework for compulsory access to intellectual-property-protected information.

Principle

IP rights do not automatically immunise conduct from Article 102 TFEU.

But compulsory licensing is an exceptional remedy, not a general rule.

Digital-maintenance application

Consider:

OEM owns copyright in diagnostic software.

An independent repairer requests access.

The competition authority would need to examine whether the demanding conditions for an abuse are satisfied.

9. Case Law 4 — IMS Health

IMS Health GmbH & Co OHG v NDC Health GmbH & Co KG

C-418/01, Court of Justice, 29 April 2004

IMS Health concerned a structured data system and refusal to license intellectual property.

The Court developed the exceptional-circumstances doctrine further.

Important considerations include whether:

access is indispensable;

refusal eliminates effective competition;

the refusal prevents the appearance of a new product or service;

there is objective justification.

Application to digital control systems

Imagine that an OEM controls the only practical interface through which independent repairers can interact with a machine's control system.

The question becomes:

Is access genuinely indispensable, or can the independent provider develop an alternative?

If a viable alternative exists, the compulsory-access argument becomes much weaker.

10. Case Law 5 — Oscar Bronner

Oscar Bronner GmbH & Co KG v Mediaprint

C-7/97, Court of Justice, 26 November 1998

Bronner established a strict test for refusal to provide access to infrastructure.

The Court rejected an abuse claim because alternative distribution systems existed and the infrastructure was not sufficiently indispensable. (Infocuria)

Principle

A dominant company is not normally required to provide access to every facility or system that competitors would find useful.

The access must satisfy a demanding indispensability requirement.

Digital application

Suppose an OEM refuses access to its diagnostic platform.

The independent repairer must consider:

Can another diagnostic system be developed?

Can data be obtained elsewhere?

Can an alternative interface be built?

Is the OEM's system genuinely indispensable?

If yes, the Bronner doctrine may become important.

11. Case Law 6 — Microsoft

Microsoft Corp v Commission

T-201/04, General Court, 17 September 2007

Microsoft concerned refusal to provide interoperability information to competitors in the work-group server operating-system market.

The General Court upheld the Commission's finding concerning Microsoft's refusal to supply interoperability information and the resulting effects on competition. (Infocuria)

Importance

Microsoft is highly relevant to digital control systems because it demonstrates that interoperability information can itself be an important competitive input.

Application

An OEM might control:

communication protocols;

API specifications;

diagnostic interfaces;

software documentation.

If independent maintenance providers cannot interact with the equipment without this information, competition concerns may arise.

12. Case Law 7 — CEAHR v Commission

CEAHR v Commission

T-712/14, General Court, 23 October 2017

This case directly concerned an aftermarket.

Independent watch repairers complained that Swiss watch manufacturers were restricting the supply of spare parts.

The case expressly concerned:

selective repair systems;

refusal to supply spare parts;

primary market;

aftermarket;

elimination of effective competition.

The General Court dismissed CEAHR's action against the Commission's decision rejecting the complaint. (curia)

Importance

CEAHR demonstrates that an aftermarket theory requires careful examination.

It is not enough to say:

“The manufacturer controls spare parts, therefore Article 102 is automatically violated.”

The market structure, competitive effects and legal conditions must be established.

Digital application

The same reasoning can be applied to:

proprietary maintenance software;

software-enabled spare parts;

diagnostic licences;

digital authentication systems.

13. Case Law 8 — Huawei v ZTE

Huawei Technologies v ZTE

C-170/13, Court of Justice, 16 July 2015

Huawei concerned a standard-essential patent (SEP) and the interaction between intellectual-property rights and Article 102 TFEU.

The Court established a framework governing when seeking an injunction based on an SEP can amount to abuse where the patent holder has undertaken FRAND licensing commitments. (Infocuria)

Why it matters here

Digital control systems increasingly use standardised communication technologies.

If a dominant manufacturer controls critical IP necessary for interoperability, questions may arise concerning:

licensing;

access;

interoperability;

FRAND commitments;

injunctions.

Huawei is not an aftermarket maintenance case, but it provides an important IP/access analogy.

14. Aerospace Aftermarket Evidence

European Commission merger investigations provide particularly useful evidence about the practical structure of aerospace aftermarkets.

In its UTC/Goodrich analysis, the Commission noted that independent MRO providers could depend on OEMs for particular repairs because of specialist expertise or lack of tooling and test equipment. It also found that, for flight-critical systems, third-party replacement parts were limited and that OEMs could hold near-monopoly positions for particular spare parts. (European Commission)

This is highly relevant to digital control systems.

The traditional dependency:

OEM → spare part

can evolve into:

OEM → spare part + software + diagnostic data + authentication + firmware.

15. Digital Lock-In

Digital lock-in occurs when the customer cannot easily move from the OEM ecosystem.

For example:

Aircraft

↓

OEM control unit

↓

OEM diagnostic software

↓

OEM cloud

↓

OEM authentication

↓

OEM repair

The customer may technically own the aircraft, but practical maintenance remains dependent on the OEM.

16. Software as a Gateway

A physical spare part may not be enough.

Suppose an independent MRO purchases a replacement control unit.

To install it, the system requires:

software recognition;

authentication;

calibration;

firmware installation;

cybersecurity validation.

If only the OEM can perform these steps, the OEM may control the entire maintenance process.

This is sometimes called digital gatekeeping.

17. Data Access Risks

Modern maintenance systems generate enormous amounts of data.

Examples:

fault codes;

sensor readings;

component life;

temperature;

vibration;

usage patterns;

maintenance history;

predictive-failure information.

If the OEM alone controls this information, independent MRO providers may receive insufficient information to compete effectively.

This can produce:

Information asymmetry → reduced independent repair → stronger OEM aftermarket position.

The European Commission's research on connected products has similarly identified data portability, switching costs and network effects as factors capable of affecting competition in digital maintenance aftermarkets. (JRC Publications)

18. Remote Disablement

A particularly serious future issue is remote control over maintenance functionality.

Suppose:

An aircraft component can operate only while a cloud authorisation remains active.

The OEM could theoretically control:

activation;

updates;

diagnostic access;

repair authorisation;

component replacement.

This creates a potential competition concern if the system is used to exclude independent maintenance providers.

However, safety and cybersecurity requirements may provide legitimate reasons for access restrictions.

Therefore:

security justification ≠ automatic illegality, but it must be genuine and proportionate where competition law applies.

19. Cybersecurity as a Justification

Manufacturers may legitimately argue:

“We cannot give independent repairers unrestricted access because this could compromise aviation safety or cybersecurity.”

That can be an important objective justification.

The competition-law analysis should therefore distinguish:

Legitimate restriction

Access is restricted because uncontrolled access creates a demonstrated safety or cybersecurity risk.

Potentially problematic restriction

The safety justification is used broadly to prevent independent repair even where:

secure access could be provided;

certification mechanisms exist;

controlled APIs are possible;

independent providers can meet objective standards.

20. Excessive Pricing

A dominant OEM may potentially charge excessive prices for:

proprietary software licences;

diagnostic subscriptions;

authentication;

spare parts;

maintenance;

cloud access.

However, high prices alone do not automatically establish abusive excessive pricing.

The legal test is demanding and requires analysis of the relationship between price, economic value and the competitive context.

21. Discriminatory Access

An OEM might provide:

If similarly situated independent providers receive materially worse conditions, competition authorities could investigate whether the difference is objectively justified.

22. Bundling and Tying

A manufacturer could potentially require:

“To purchase our control-system software, you must also purchase our maintenance service.”

Or:

“Only customers using our authorised MRO network receive software updates.”

Such arrangements may raise Article 102 concerns where dominance, coercion and exclusionary effects are established.

The analysis would examine:

separate products;

dominance;

contractual conditions;

foreclosure;

customer choice;

efficiencies;

objective justification.

23. Repair Data as an Essential Input

One of the most difficult legal questions is:

When does maintenance data become indispensable?

Possible evidence includes:

whether the information is unique;

whether it can be recreated;

whether independent diagnostics are possible;

cost of alternative data generation;

technical compatibility;

availability of third-party tools.

Under Bronner, indispensability is a demanding concept. (Infocuria)

But the later digital-platform jurisprudence shows that the precise application of Bronner can depend on how the infrastructure was designed and whether the dominant company developed it for third-party use. The Court has recently explained that where a dominant undertaking developed infrastructure specifically so third parties could use it, the strict Bronner indispensability condition may not apply in the same way. (Infocuria)

This is highly significant for digital maintenance platforms.

24. Interoperability

Interoperability means that an independent system can communicate with the OEM's system.

For example:

Independent diagnostic software

↕️

OEM control system

If the OEM prevents this communication without legitimate justification, competition may be restricted.

Microsoft provides a strong analogy because interoperability information was central to the infringement. (Infocuria)

25. Self-Preferencing

A manufacturer may operate:

the control system;

the diagnostic platform;

the official MRO network.

It might therefore have an incentive to favour its own MRO operations.

For example:

Independent MRO receives data after 24 hours.

OEM MRO receives data in real time.

This could make independent competitors less effective.

The legal assessment would depend on dominance, conduct and competitive effects.

26. Exclusive Maintenance Contracts

An OEM may offer:

“Five-year maintenance contract + software + spare parts.”

Long-term contracts can generate efficiencies and predictability.

But competition concerns can arise if they cover a large proportion of demand and prevent independent MRO providers from obtaining customers.

The analysis would consider:

duration;

market coverage;

termination provisions;

rebates;

exclusivity;

alternatives;

OEM market power.

27. Aftermarket Monopoly and Merger Control

The problem can also arise through mergers.

If two major suppliers combine:

OEM A + digital maintenance platform B

the merger might create:

control over technical data;

control over diagnostic software;

control over spare parts;

control over maintenance;

control over installed equipment.

The Commission's merger framework recognises that mergers may create or strengthen dominant positions and reduce competition through higher prices, reduced choice or reduced innovation. (Competition Policy)

The Commission currently lists numerous transactions within the aircraft repair and maintenance sector, showing that aftermarket MRO markets are subject to EU merger scrutiny. (Competition Case Search)

28. Aerospace Example

Consider an aircraft control-system manufacturer, AeroControl.

It sells a control unit for €500,000.

After installation:

AeroControl owns the diagnostic software;

AeroControl controls the firmware;

AeroControl owns the cloud platform;

AeroControl supplies authentication keys;

AeroControl controls technical data;

independent MRO companies need those inputs.

The initial aircraft-equipment market may be competitive.

But ten years later:

AeroControl = dominant supplier of digital maintenance inputs.

Potential competition concerns include:

refusal to provide diagnostic access;

discriminatory data access;

excessive software charges;

tying software to OEM maintenance;

restrictive licensing;

exclusion of independent MRO providers;

technical interoperability restrictions.

29. Primary Market vs Aftermarket

The Hugin case demonstrates why the two markets may need separate analysis. (Eur-Lex)

30. Major Legal Risks

1. Refusal to supply

OEM refuses spare parts or digital access.

2. Refusal to license

OEM refuses necessary software or IP access.

3. Interoperability restriction

OEM prevents third-party systems from communicating.

4. Data foreclosure

Independent MROs cannot obtain necessary maintenance data.

5. Tying

Software access conditioned on OEM maintenance.

6. Exclusive dealing

Customers required to use OEM MRO services.

7. Discriminatory access

OEM MRO receives better information.

8. Excessive pricing

Dominant OEM charges potentially excessive aftermarket prices.

9. Margin squeeze

OEM supplies inputs to independent MROs at conditions that make downstream competition difficult.

10. Merger-created foreclosure

Acquisition combines control over equipment, data and maintenance.

31. Six Core Cases for Examination

32. Direct vs Analogical Authorities

For accuracy, these cases should not all be described as aircraft-maintenance cases.

Directly relevant aftermarket authorities

Hugin

CEAHR

Strong general aftermarket/IP authorities

Volvo v Veng

Magill

IMS Health

Bronner

Digital/interoperability authority

Microsoft

IP/interoperability licensing authority

Huawei v ZTE

The absence of a large body of CJEU judgments specifically concerning modern aircraft digital-control maintenance monopolies means that these principles must be applied by analogy.

33. Remedies

Potential competition-law remedies can include:

Access remedies

Provide independent MROs with necessary information.

Interoperability remedies

Permit third-party diagnostic tools to communicate with OEM systems.

Licensing

Provide software or IP licences under appropriate conditions.

Non-discrimination

Require equivalent access conditions for OEM and independent repairers.

Data portability

Allow customers or authorised providers to access relevant maintenance data.

Contractual remedies

Remove excessive exclusivity or tying conditions.

Structural remedies

In merger cases, divest businesses where necessary to preserve competition.

34. Key Evidence

A competition authority or private claimant could examine:

software architecture;

APIs;

access logs;

diagnostic protocols;

licensing agreements;

repair contracts;

spare-part prices;

maintenance prices;

authentication requirements;

technical manuals;

data-access records;

customer switching evidence;

internal OEM documents;

independent MRO costs;

cybersecurity justifications.

Digital evidence is particularly important because the restriction may not appear in a conventional contract.

35. Simple Exam Example

Suppose AeroTech controls 80% of a particular aircraft-control system aftermarket.

It tells independent MRO providers:

“You may repair the physical component, but only AeroTech can access the diagnostic software.”

Independent MRO providers cannot compete effectively without the software.

The legal analysis would be:

Step 1: Define the relevant aftermarket.

Step 2: Determine whether AeroTech is dominant.

Step 3: Determine whether diagnostic access is indispensable.

Step 4: Examine whether alternatives exist.

Step 5: Examine whether refusal excludes effective competition.

Step 6: Examine whether AeroTech has an objective safety/cybersecurity justification.

Step 7: Apply Article 102 TFEU and relevant IP/interoperability principles.

Step 8: Consider remedies.

36. Important Distinctions

Ownership of equipment ≠ ownership of the aftermarket

A manufacturer does not automatically obtain unlimited control over every subsequent maintenance service.

IP protection ≠ immunity from competition law

Volvo, Magill and IMS Health demonstrate that IP rights can interact with Article 102 in exceptional circumstances.

High switching costs ≠ automatic dominance

They are evidence, not conclusive proof.

Safety restrictions ≠ automatic abuse

Aviation safety and cybersecurity may provide legitimate justification.

Data control ≠ automatic essential facility

Indispensability must be established under the applicable legal framework.

37. Ultra-Basic Revision Formula

Aftermarket Digital Control Monopoly = Installed Base + Proprietary Software + Technical Data + Authentication + Switching Costs + Limited Alternatives → Potential Aftermarket Dominance → Refusal/Discrimination/Tying/Interoperability Restriction → Article 102 TFEU Risk.

Case-law formula

Hugin = Spare Parts
Volvo = IP + Spare Parts
Magill = Exceptional Licensing
IMS = Indispensability
Bronner = Essential Facility
Microsoft = Interoperability
CEAHR = Aftermarket Repair
Huawei = IP + Interoperability Licensing

38. Conclusion

Aftermarket Digital Control Systems and Maintenance Monopoly Risks represent an important evolution of traditional aftermarket competition law.

Historically, the concern was:

“The manufacturer controls the spare parts.”

Today it can become:

“The manufacturer controls the spare part, diagnostic software, maintenance data, authentication, firmware, cloud platform and repair authorisation.”

That combination can produce significant customer lock-in and potentially allow an OEM to extend power from the primary equipment market into the aftermarket.

The most important legal foundations are Hugin, which demonstrates the possibility of a distinct spare-parts aftermarket; CEAHR, which shows the importance of careful primary-market/aftermarket analysis; Volvo, Magill and IMS Health, which govern exceptional conflicts between IP rights and competition; Bronner, which establishes the demanding refusal-to-supply framework; and Microsoft, which demonstrates the importance of interoperability information in digital markets. (Eur-Lex)

Final exam line:

Digital Maintenance Monopoly = OEM Installed Base + Proprietary Control System + Data/Software Dependency + Interoperability Barriers + High Switching Costs + Limited Alternatives + Exclusionary Conduct = Potential Article 102 TFEU Aftermarket Abuse.