On the Stop Rule in accident investigations... #readingToday

While some readers may take argument with Nietzsche's view that the main reason for the search for causes is to relieve a sense of anxiety and unease, others may wholeheartedly agree that it often is so, not least in cases of unusual accidents with serious adverse outcomes. Whatever the case may be, the quotation draws attention to the more general problem of the stop rule. When embarking on an investigation, or indeed on any kind of analysis, there should always be some criterion for when the analysis stops. In most cases the stop rule is unfortunately only vaguely described or even left implicit. In many cases, an analysis stops when the bottom of a hierarchy or taxonomy is reached. Other stop rules may be that the explanation provides the coveted psychological relief (Nietzsche's criterion), that it identifies a generally acceptable cause (such as 'human error'), that the explanation is politically (or institutionally) convenient, that there is no more time (or manpower, or money) to continue the analysis, that the explanation corresponds to moral or political values (and that a possible alternative would conflict with those), that continuing the search would lead into uncharted – and possibly uncomfortable – territory, etc.

The ETTO Principle Erik Hollnagel