Company case

Siemens: inspectors caught more defects when the AI showed what it had seen

Researchers gave 48 inspectors at a Siemens electronics factory an AI aid for checking circuit boards. Half saw only the AI’s score. Half also saw a picture marking where the AI had found a problem. The second group caught more defects, and most of them did better than the AI working alone.

Outcome Measured result

Researchers measured the result and published how.

At a glance

Company
SiemensIndustrial manufacturer; the study was run at its electronics factory in Zug
Size
Enterprise (1,000+ employees)
Industry
Manufacturing
Where and when
Switzerland. June – July 2021, published December 2024.
Who produced the figures
Measured by researchersThe figures come from a preregistered experiment by university researchers, published in a peer-reviewed journal. One of the authors reports research funding from Siemens.

What they did

Workers at the Siemens factory in Zug check printed circuit boards by eye. They look for missing, wrong or faulty components. Researchers copied this job into an experiment and ran it on site with the factory’s own staff.

An AI system gave each board a quality score from 0 to 100. A low score meant a likely defect. Workers were told that the AI could be wrong. Each worker then decided whether the board was faultless or defective.

The workers were split at random into two groups:

  • Score only. These workers saw the AI’s score and nothing else.
  • Score plus a picture. These workers also saw the image with coloured areas marking where the AI had found a problem. The underlying AI was the same.

In all, 48 workers each judged 200 images of four types of board. Of the 200 boards, 28 were defective. The workers had 13.8 years of experience on average.

The numbers

Defective boards caughtOverall accuracy
Workers with the score only82.0%88.6%
Workers with the score and the picture93.0%96.3%
The AI alone92.9%95.6%

Overall accuracy here gives equal weight to faultless and defective boards.

  • People with the score alone did worse than the AI alone. They were 3.6 times more likely to overrule the AI when it was right.
  • People with the picture did better than the AI alone. 73.1% of these workers beat it.
  • They also caught its mistakes. Workers with the picture overruled 96.9% of the AI’s wrong predictions. Workers with the score alone overruled 86.4%.

What the case shows

  • Adding a person to an AI can make the result worse. Experienced inspectors with a bare score threw away correct answers.
  • How the AI presents its answer matters as much as how good it is. The same AI gave a better result once workers could see what it was reacting to.
  • Test the pairing on the real task. The factory learned this from 48 people and 200 images in ten days.
  • When you buy an inspection system, ask what the operator will see. A score with no reason attached is hard to judge.

What this says about the practices

Practices the company applied

Sources

  1. Senoner, Schallmoser, Kratzwald, Feuerriegel and Netland (2024). Explainable AI improves task performance in human–AI collaboration. Scientific Reports, 14, 31150. doi.org
  2. Senoner, Schallmoser, Kratzwald, Feuerriegel and Netland (2024). Explainable AI improves task performance in human–AI collaboration. Scientific Reports, 14, 31150. What this study did and found
  3. Vaccaro, Almaatouq and Malone (2024). When combinations of humans and AI are useful: A systematic review and meta-analysis. Nature Human Behaviour, 8(12), 2293–2303. What this study did and found