What is Human Error?
Risk events often have many contributing causes, a common one being ‘human error’. But what is human error can be adequately mitigated? Human error can be defined as being a ‘failure of a planned action to achieve a desired outcome’.
Actions can fail to achieve the desired outcome if the action itself is inadequate for the purpose for which it was designed; or the action can be adequate but the execution of the action can be deficient – either through unintentional or intentional behaviours of people. Related article Expected and Targeted Risks.
There are therefore six possible outcomes in the combination of plan and human action:
- An adequate plan that is intentionally followed will likely result in the avoidance of the risk event
- An adequate plan that is unintentionally not followed will likely result in failure – a risk event caused by human error
- An adequate plan that is intentionally not followed will likely result in failure – a risk event caused by malice
- An inadequate plan that is intentionally followed will likely result in failure – a risk event caused by poor planning
- & 6. An inadequate plan that is unintentionally or intentionally not followed has a higher likelihood of failure or success of meeting the ultimate objective.
Is the case of the Piper Alpha disaster, where personnel who followed the muster procedures found that they could not access the lifeboats from the accommodation block, personnel who survived the disaster were those who (unintentionally or intentionally) chose to violate the muster rule and ‘step off’ the platform into the ocean. Therefore, an inadequate rule (plan) was violated and the ultimate objective (no fatalities) was individually achieved as these people avoided the risk event.