Functional Safety 2016

Challenge for SIL assessment - Human error rates

By directly observing people at work, specialists in human reliability found that

there are four basic types of human failure

[1]

• Slip – e.g. press button “A” instead of button “B”

• Lapse – e.g. skip steps of sequence (e.g. following an interruption)

• Mistake – e.g. incorrect diagnosis of situation

• Violation – deliberate breach of rules or procedures

Ref [1] HSE Human Factors Briefing Note No. 3 Humans and Risk