A temp worker arrives at seven. The line is already short, the shift leader is on the floor, and the realistic window for instruction is about twenty minutes at the entrance. Everything the law, your client and your own safety record expect of that person has to fit in it, or it does not happen at all.
That window is the real constraint. Most flex onboarding fails not because nobody cares, but because it is designed for an hour nobody has.
What has to fit in those twenty minutes
Three different things, and they are often confused. The general company rules, which barely change. The risks and safety instructions of the specific workpost, which change with every assignment. And the proof that both were delivered to this person on this date. The first is easy to standardise and the least useful alone. The second prevents the accident. The third is what you need when someone asks afterwards.
Who owes what: the legal triangle
Agency, user company and worker each carry a defined part. Gaps appear when both parties assume the other one covered it.
Belgium
The instruction on the floor is legally the user's job, not the agency office's. Codex art. X.2-11 requires the user, or the designated member of the hierarchical line, to give every temp worker the information on the risks at the workpost, to give the safety instructions specific to that workpost, and to arrange training in line with art. I.2-21.
The agency owns the paperwork. The user draws up the werkpostfiche (workstation record sheet, model in annex X.2-1) under art. X.2-3 §2, and only for workposts or functions where health surveillance is compulsory, not for every assignment. Under art. X.2-4 and X.2-5 the agency completes sections C and D, keeps a copy, hands a copy to the temp worker and presents it to the inspection.
Then the hard line: art. X.2-17 forbids both the user and the agency from deploying a temp worker at a workpost for which no werkpostfiche has been drawn up and about which the worker has not been informed. The consequence to quote is not a fine, it is that the person may not start.
Netherlands
The chain runs inlener, uitlener, worker. Arbowet art. 5 lid 5, the doorgeleidingsplicht, requires whoever has work done by a worker made available to them to provide the uitlener, in good time before the work starts, with the description from the RI&E of the hazards and the risk limiting measures, so that the uitlener passes that description to the worker. Waadi art. 11 puts the mirror obligation on the agency: it provides information about the required occupational qualification and passes on that art. 5 lid 5 description before the assignment begins.
The collective agreement adds a deadline in plain language. The CAO voor Uitzendkrachten 2026-2028, article 19, obliges the agency to inform the temp worker, before the work at the client starts, about the required qualifications, the possible safety and health risks, and how to deal with them.
Two things worth saying out loud. The Arbowet counts the inlener as the employer for a worker made available, so the art. 8 duties sit with them too. And the SNA keurmerk says nothing about safety instruction; it is a fiscal and administrative standard.
Why this group, specifically
The Nederlandse Arbeidsinspectie's Monitor Arbeidsongevallen 2024, published on 2 October 2025, found that in 18 percent of the investigated accidents the victim was a temp worker, while temp workers make up roughly 4 percent of the working population. In industry it was nearly 25 percent of victims, against an estimated 8 percent of the sector's workforce. That is investigated accidents, not all accidents, and the workforce share is an estimate. The distance between the two numbers is still the point.
The explanation is not that temp workers are careless. It is that they are new, on an unfamiliar site, often without the language of the manual, and expected to be productive on day one.
Twenty minutes, on a phone, at the entrance
A classroom induction does not fit. A signature on a form fits, but proves attendance rather than understanding. What does fit is a short course on the worker's own phone, done at the entrance or in the canteen before the shift.
Aristotl builds those courses from the documents you already have: the werkpostfiche, the RI&E extract, the site rules, the machine instruction. Modules run three to five minutes, on mobile, with no laptop and no app installation. They are assigned per client site, so someone going to plant A gets plant A's risks and not a generic module. Each module is translated automatically per worker, in their own language, which for this group is usually the difference between reading it and nodding at it. Knowledge checks show the content landed. And completion is registered per person, per site and per version, and exports.
For an agency, that means showing per worker and per assignment what was delivered and when. For a user company, the instruction you owe is delivered before the first shift, not during it.
Bring one werkpostfiche or one site's rules to a demo and we will show you the course a temp worker would get tomorrow morning, and the record you would hold afterwards.