Humans, The Ultimate Backup

Humans have exhibited multiple capabilities with unmatched potential for overcoming system and software failures. They can provide backup and are often used to repair or replace a failed systems or piece of equipment. Current HRA concepts and methodologies use the same model logic as PRAs which is based on equipment system and component reliability. This assumes that human actions should always succeed and that the “human error” calculated by HRA methodologies corrects this assumption to incorporate the fact that humans are not one hundred percent reliable. However, what is not calculated are the multitude of small actions humans perform that head off failures. Human contributions for continued successful operation is taken for granted. Workers often catch potential failures before they occur by addressing small failures and address situations before they become major problems or result in catastrophic failures. Although these additional contributions are difficult to identify and quantify, they provide additional understanding of how human involvement can lower risks and improve safety. Some of these concepts are addressed in the precepts of human resilience engineering.