In The Field Guide to Understanding Human Error, Sidney Dekker introduced the bad apple theory. According to Dekker, we often view individuals as the root of human error and failure as the result of these individuals’ mistakes. In order to weed out the “bad apples,” we must “get rid of them, retrain them, or discipline them.” After all, as the saying goes, one bad apple can spoil the bunch. Yet according to Dekker, this mind-set does not lead to learning or safer work environments. In order to make progress on safety, we must learn from failure.

One step toward promoting a learning culture is to take a systems approach to safety.