234 incidents on record · 2026HeadlightsIncident reports by Ellie Harris · Melbourne
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HD-INC-229
Workplace relations · Spain · 2025 · A scheduling tool allocated staff rest days by a mathematical formula while the employer told union representatives it used no algorithms or automated decision systems, and withheld the formula's parameters from worker representatives

Spain's National Court Held Foundever Withheld the Formula That Set Staff Rest Days

By Ellie Harris · Filed Formula in use for rest days at the Barcelona, Madrid and Seville sites

Alleged: Foundever Spain S.A. developed or deployed the AI system implicated in this incident. Details are drawn from public reports; parties are presumed innocent of any wrongdoing not established by an official finding.

Spain's National Court Held Foundever Withheld the Formula That Set Staff Rest Days

What happened

At Foundever’s contact centres in Spain, staff have rest days allocated according to how many people the company needs working each day.

But when the union CGT asked how those decisions were being made, the company said it did not use algorithms.

It was reported that CGT took Foundever to Spain’s National Court (Audiencia Nacional) after the company failed to disclose the rules used to allocate rest days at its Barcelona, Madrid and Seville sites. Three other unions, CCOO, USO and CSIF, joined the claim.

According to the judgment, CGT’s union sections had asked about algorithms affecting staff, including the allocation of rest days. On 15 July 2024, Foundever replied: “We do not use algorithms or automated decision systems, still less artificial intelligence.”

What an auditable version would have shown

The court found that Foundever was using an algorithm to decide when employees could take their rest days.

The system worked by taking the company’s forecast of how busy it expected to be, calculating how many staff were needed each day and using a mathematical formula to distribute rest days.

Under Article 64.4.d of Spain’s Workers’ Statute, works councils have the right to know the rules, parameters and instructions behind algorithms that affect working conditions.

The court found that Foundever had withheld this information from CGT and, in doing so, breached the union’s freedom of association.

Where the gap was

The court declared the company’s conduct void. It ordered Foundever to immediately disclose the formula’s parameters, rules and instructions for its Barcelona, Madrid and Seville sites. The company was also ordered to pay CGT 6,250 euros in damages.

The judgment was dated 4 July 2025 and became public in December 2025, when the union announced the outcome.

A ConductRecord keeps, for each rest day assigned, the forecast used, the rule applied and the result, so worker representatives can see how the formula works.

A MetricRecord is designed to produce signed figures, such as how rest days were spread across staff, that a works council or court can verify.

ConductRecord and MetricRecord are Headlights designs.

What governance should have looked like

The judgment could be appealed to the Supreme Court. As of 4 October 2026, the sources reviewed showed no appeal decision.

When a company uses a formula to decide when employees work and when they rest, best practice would be to explain how those decisions are made, share the rules with worker representatives and keep records showing how rest days were allocated.

Failure Pattern: according to Spain’s National Court, an employer allocated staff rest days with a formula-based tool while telling the union it used no algorithms, and withheld the formula from worker representatives.

Governance Principle: an employer that uses an automated formula to set working conditions should say so and give worker representatives its rules when they ask.

The reference implementation of ConductRecord and MetricRecord is open source. It lives at github.com/saffronandindia/headlights-oss, Apache 2.0 licensed and free to install. The repository is public now.

Sources

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The record

An auditable system would have produced a signed, tamper-evident record the moment this happened: what the system did, the version that did it, the basis it acted on, and the action taken, and Foundever Spain S.A. could have produced it on demand.

This is the record the system as deployed did not produce in a signed, auditable form.

What this teaches
Capture what happened when it happens
What the system did, the version that did it, the basis it acted on, and the action taken, recorded at the moment, not reconstructed after.
Sign it, so no one has to trust the record-keeper
A tamper-evident entry. Edit it later and the signature breaks. The record does not ask for the benefit of the doubt.
Make it verifiable by anyone
A court, a regulator, a customer's lawyer can check the record themselves, without taking the company, or us, at our word.

Headlights summarises publicly reported AI incidents. All summaries are independently written, attributed to their original sources, and intended for research and educational purposes. Allegations are identified as such until established through official findings.

Last reviewed October 2026. This report is based on the sources listed above and reflects information available at the time of review; later developments may not be captured. Where a person is described as charged with or alleged to have done something, that allegation is unproven unless a conviction or a court or regulatory finding is stated. Headlights publishes journalism and commentary, not legal advice.

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