AI Retrofits in Manufacturing: When Do Operators Become Manufacturers?

Many production machines are mechanically far from reaching the end of their service life. Digitally, however, they are often no longer up to date. Instead of replacing an entire system, companies retrofit it with cameras, sensors and AI systems.

This can be economically attractive. However, modifying a machine can also cause a company to assume additional manufacturer responsibilities. Anyone who purchases a finished machine and uses it as intended is generally considered its operator. Anyone who makes substantial modifications to it may become a manufacturer themselves.

When Robots Learn to See

An example of what an AI retrofit can look like is an application at Stellantis described by the New York Times. An older industrial robot at a plant in Detroit had difficulty picking up body parts when they were not positioned exactly where expected. Instead of replacing it, the robot was retrofitted with a camera, a computing unit and an AI system.

The system detects the position and orientation of the component and sends corrected coordinates to the robot. The robot can then adapt its movement accordingly. The technical operation is also described in a supplementary publication by the provider Inbolt.

Here, AI improves the production process. However, its outputs also influence the machine's movements. This raises the question of the potential safety consequences of incorrect detection.

AI can also be used specifically to protect people. This approach is being investigated in the Fraunhofer PROTECT project. The camera-based system distinguishes people from automated guided vehicles and enables the robot's speed to be adjusted according to the situation. AI-based recognition is combined with conventional motion detection.

PROTECT therefore illustrates another potential application in which AI is directly integrated into the safety concept. Whether implementing this approach on an existing machine would constitute a substantial modification would need to be assessed separately.

For a retrofit, the decisive factor is not simply which technology is added. What matters is how it changes the machine's behaviour and which protective measures are consequently required.

When Does an Operator Become a Manufacturer?

The EU Machinery Regulation, which applies from 20 January 2027, defines when a subsequent modification is considered substantial. This requires a physical or digital modification that was not envisaged or planned by the original manufacturer and that creates a new hazard or increases an existing risk. In addition, the modification must make additional safeguards, whether physical or non-physical, necessary, with their integration requiring an adjustment to the existing safety control system. Alternatively, additional protective measures must be necessary to ensure stability or mechanical strength. Not every change to a movement sequence or safety function meets these criteria.

For an AI retrofit, it must therefore be assessed on a case-by-case basis whether incorrect detection could trigger hazardous movements, whether the existing safety concept already addresses these risks and which additional protective measures are necessary.

Based on the publicly available information, it is not possible to determine whether the Stellantis retrofit meets these criteria. The legal assessment of such a modification requires a risk assessment of the specific case.

If a substantial modification has been made, the person carrying it out is considered the manufacturer of the modified machine. This may be the existing operator. If a system integrator is commissioned to carry out a substantial modification, the actual division of responsibilities is decisive.

The New Role Brings New Obligations

The new manufacturer must ensure the conformity of the modified machine under its own responsibility. This includes the risk assessment, technical documentation and the applicable conformity assessment procedure, including the EU Declaration of Conformity and CE marking.

Implementation can be particularly complex for older systems. If technical documents, information about the control architecture or the necessary access rights are missing, the modification may only be possible to assess and document with the support of the original manufacturer. In addition to the camera, software and integration, companies must also plan for safety evidence and potential delays before the machine can be put back into operation.

How the AI Act Comes into Play

Not every AI system used in a production facility qualifies as high-risk AI. For product-related systems, classification generally requires that the AI is a safety component or constitutes a product covered by the relevant legislation, and that the product is subject to a conformity assessment by an independent body.

For machinery, the current version of the AI Act contains a special provision. The general high-risk requirements and provider obligations do not apply directly to these product-related systems in the same way as they do to other high-risk AI systems. An AI retrofit therefore does not automatically make the operator a provider under Article 25 of the AI Act as well.

Instead, the intention is to incorporate the relevant AI requirements into the Machinery Regulation through supplementary legal acts. These must become applicable by 2 August 2028. For retrofits, manufacturer responsibility for the modified machine therefore remains the central starting point.

Practical Advice for Operators and System Integrators

Before commissioning a third party to carry out an AI retrofit, companies should document the machine's existing condition, the planned modification and the safety functions affected. This provides a basis for determining whether the modification is substantial and who will assume the resulting manufacturer obligations.

The contract should clearly specify who is responsible for the safety assessment and any conformity assessment that may be required. Responsibilities under public law cannot be freely reassigned by contract. However, the support the company needs to fulfil its obligations should be secured in a binding agreement before the modification begins.