Many major accidents e.g. Piper .Alpha, Chernobyl, were initiated by human failure. Human failure is not random and people's actions are rarely malicious and usually make sense to them at the time.
This is the second guiding principle for OCIMF actions on human factors, highlighting the importance of understanding My errors occur in order to develop effective controls.
Everyone can make errors no matter how well trained and motivated they are. However, in the workplace, the consequences of such human failure can be severe and thus every organization needs to be able to identify possible human failures. In that regard, a risk assessment helps to identify areas of human failure in safety critical tasks and control measures.
Source: Safet4Sea