Human error root causes poster

"Operator error" is where a root cause analysis should start, not where it stops. A person makes a mistake for a reason: they did not know, could not do it, the process let the mistake through, the standard was unclear, the workplace got in the way, or attention slipped. Each reason has a different fix, and retraining fits only the first. This poster sets out the six reasons with the countermeasure that matches each.

Download the poster

The PNG is free to download now. The print-ready vector PDFs open after a short form, once.

Download PNG (300 dpi)2550 x 3300 px, prints at 8.5 x 11 in · 437 KB · no form

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Human error root causes poster — 24 x 36 in18 x 24 inA2A3LetterA4PNG 300 dpi

The words on the poster

Look past human error

Ask why the mistake was possible. Then fix that.

Didn't know Not trained, or no standard. Fix: write the standard, train, check understanding.
Couldn't do it Knows how, lacks the skill. Fix: practice with a trainer, sign off on the job.
Process allowed it Easy to do wrong, nothing catches it. Fix: error-proof it or add a check.
Unclear standard Vague, out of date or conflicting. Fix: rewrite it with pictures, at the station.
Workplace Poor light, noise, reach, clutter, time pressure. Fix: change the workplace.
Attention slipped Knew and could, but missed it. Fix: make the error impossible or obvious.

"Retrain the operator" is not a fix unless the person really did not know. "Be more careful" never is.

On the floor

How to use it

Putting the Human error root causes poster to work

1
Use it whenever a 5 whys or an incident report ends at "operator error".
2
Ask the person involved which card fits, in a no-blame conversation.
3
Check the countermeasure on the corrective action matches the card, not just "retrain".
4
Pair it with the free root cause analysis template and poka-yoke worksheet.

Where the poster goes and how to teach with it, in the order to try them.

Which size to print

24 x 36 in or A2: a main wall or team board, read from a few metres away.
18 x 24 in or A3: a station or notice board. The A3 file also fits 11 x 17 in paper.
Letter or A4: a clipboard, binder or handout, on any office printer.

Every PDF is vector, so it stays sharp at full size. Nothing runs to the edge of the page, so no bleed is needed.

Sources and notes

The six reasons are a common shop floor grouping. For the theory behind slips, lapses and mistakes see James Reason, Human Error (Cambridge University Press, 1990).