The Machinery Regulation wants *five years of software logs*

Why five years matters

Most machines last longer than the phone in your pocket. A robot on a production line might run for a decade, and when something goes wrong years after installation, the first question is often: which software was it running?

The Machinery Regulation, which applies from 20 January 2027, asks manufacturers to answer that question ^[1]. Safety-relevant software changes must be logged and traceable for five years. That's not five years from when the machine was built, but five years that roll forward as the machine keeps running and updating.

It's a bit like keeping receipts for a lease car. You don't just need the original purchase invoice. You need a record of every service, every part replaced and every software update, for as long as the lease runs and a bit beyond. If something breaks and the warranty is questioned, those receipts decide who pays.

For machinery, the same logic applies. A machine placed on the market after 20 January 2027 falls under the new regulation ^[1]. If it gets software updates, those changes need to be documented, and the documentation needs to stay intact and checkable for five years.

What the regulation says

The Machinery Regulation sets out essential health and safety requirements that machinery must meet before it can be placed on the EU market. Among them: machinery must be protected against corruption, and safety-relevant software changes must be logged and traceable for at least five years ^[1].

For machinery with self-learning behaviour, there are additional requirements. The manufacturer must document how the machine learns, what it learns from and how that learning is monitored and controlled.

The regulation doesn't spell out exactly how to keep the logs or how to prove they haven't been tampered with. It says what must be logged and for how long. The question of how to protect those logs, and how to show later that they're the same logs written at the time, is left to the manufacturer.

The problem with logs you keep yourself

Logs are like a work diary. They're useful when you need to remember what happened, but they're only as trustworthy as the person keeping them.

If a machine injures someone and a lawyer asks which software version it was running on the day, the manufacturer's log is the first place anyone looks. If that log can be quietly edited by the same people who wrote it, it's easy to question. Did the log always say version 2.3.1, or was it version 2.3.0 until someone realised that mattered?

Access controls help. So does monitoring. But neither stops someone with the right access from making a change and covering their tracks. And when a dispute lands in court, the side that can't prove its records are unchanged starts on the back foot.

That's the evidence question: how do you show that a log written three years ago is exactly what was written then, when you're the one who has been keeping it all along?

How a digital witness fits here

This is a strong fit for a digital witness, because the problem is precisely about showing something unchanged over time.

Logging software changes with a checkable record

Here, the thing to seal is each safety-relevant software change: the version number, the date deployed, what changed and who approved it. Say a new firmware release goes to a batch of machines. At the moment the update is logged, the manufacturer seals a fingerprint of that log entry.

The entry itself stays in the manufacturer's system. The fingerprint goes to WitniumChain, which returns a witness ID. That ID and a link to verify the record can be stored alongside the log or sent to a notified body, an insurer or the customer.

Five years later, if someone questions whether the log has been altered, anyone with the original record can check it. They calculate the fingerprint again and compare it with the sealed one. If it matches, nothing has changed since the day it was logged, not even by someone with administrator rights. Change a single character and the fingerprint won't match.

That's what a digital witness does: it makes a log checkable by anyone, without them having to trust the manufacturer.

What it shows: that the log entry existed at that time and hasn't been altered since.

What it doesn't show: It doesn't prove the software was safe, or that the update was done correctly, or that the log is complete. It only shows that the record you're looking at is the one that was sealed.

How to start: Your system sends a fingerprint of each log entry to WitniumChain through the REST API, the SDK or the MCP server, and gets a witness ID back. To check, anyone you share the record with calculates the fingerprint again and compares it with the sealed one. The content never leaves your systems. The first 2,000 witnesses a month are free. Read the full documentation.

How it would work

1. Each time a safety-relevant software change is logged, seal a fingerprint of the entry.
2. Store the witness ID alongside the log.
3. When the log is questioned, share the entry and the verification link. Anyone can check that it matches.

What this means for you

If you manufacture machinery that will be placed on the market after 20 January 2027, here are four questions to ask now:

1. Which software changes count as safety-relevant? Not every update needs logging, but the ones that affect safety do. Define that early.
2. Where will you keep the logs, and for how long? Five years from each change, not from when the machine was built. That means a rolling archive.
3. Who can access and edit those logs? The fewer people with write access, the easier it is to defend the logs later.
4. Can you show a log hasn't changed since it was written? Access controls and monitoring are the foundation. A digital witness adds a layer that works even when someone with the right access makes a change.

The regulation is clear on what must be logged. How you make those logs hold up as evidence when they're questioned is up to you.

What to watch

The Machinery Regulation takes effect on 20 January 2027. Machinery placed on the market from that date must meet the new requirements, including the five-year logging duty.

For machinery already on the market under the Machinery Directive, the old rules still apply. The new regulation doesn't apply retroactively ^[1].

Notified bodies and market surveillance authorities will be watching how manufacturers document software changes, especially for machinery with self-learning behaviour. If you're building machines that learn, now is the time to work out how you'll show what they learned, when and from what.