Root Cause - Single Cause

Single Cause

The single cause philosophy is based on the belief that there is a single cause for any outcome that, if prevented, would prevent the outcome itself. In this context, the root cause is the cause which dominates over all other contributing factors.

This viewpoint results in the identification of a single root cause that provides a clear direction for preventing an undesired outcome. The subjective criteria used for selection of the root cause from among the contributing factors has been criticized as being arbitrary and inconsistent.

One basis for the argument supporting this as the ‘proper’ interpretation is the decomposition of the words in the phrase – the root cause is the cause at the root of the outcome. While there may be nuances in the meanings of the words, the common usage of the words lead to a straightforward and simple interpretation.

However, the notion of a single root cause is the exception, not the rule.

Every harmful effect that has ever happened occurred after the stage had been set for it to happen. The factors that set the stage for the effect are sometimes called "set-up" factors or "vulnerability" factors.

But many harmful effects for which the stage had been set do not happen. Thus there must have been a triggering factor that converted the latency to an actuality. Triggering factors are also called "initiating" factors or "precipitating" factors.

There could be "root causes" associated with each set-up factor and each initiating factor.

Most, if not all, harmful effects could have been milder or less serious than they were. Thus there must have been exacerbating factors that made the effect as bad as it was over and above the minimal set-up factors. There could be root causes associated with each exacerbating factor.