Incident Investigation
Being able to determine the root cause of incidents is a critical component of an effective Safety Management System (SMS). Operating under the presumption that there should not be any incidents (zero) if the SMS is functioning properly, each incident indicates failures or faults must be present in the current SMS. Hence the need for effective incident investigation, to determine the failures and faults in the current system so they can be corrected and prevent future incidents. However, the term root cause is often “mis-used” following an incident.
When attempting to determine why an undesirable event occurred, injury, equipment failure, quality defect etc., root cause must be established to prevent future occurrences. Unfortunately, many investigations only establish root cause leaving secondary causes and contributing factors unaddressed. Failure to identify the secondary causes and contributing factors along with root cause will often retain the same risk of future failures as correction of root cause eliminates.
System failures are seldom based on a single cause-event, but rather a series or chain of events that lead to failure. In this writer’s experience conducting hundreds of incident investigations, there are always at least two secondary cause or contributing factors (usually 3-4), which left unaddressed, will contribute to future incidents. Incident investigations need identify as many causes and contributing factors as possible to allow for system corrections, and true future incident elimination.
There are several incident investigation tools available. Many utilize lists or check-boxes of common causes and contributing factors as an aid. Regardless of the tools used, successful incident investigation includes analysis of the work environment (including equipment), work processes (how tasks are completed) and personal or people related factors (such as knowledge and decisions made). Investigating to root cause only leaves the door open to secondary causes or contributing factors to re-surface and put you at-risk of incident.
