According to the conventional interpretation of safety, here called Safety-I, safety denotes a condition where as little as possible goes wrong, the focus of practical efforts whether in management or analysis is therefore on the occurrence of unacceptable outcomes and on how to reduce their number to an acceptable level, ideally zero and the emphasis is on how to manage safety eo ipso, as seen in the ubiquitous safety management Systems (SMS).

This approach, however leads to somewhat of a paradox since Safety in this way is defined and measured more by its absence than by its presence, as noted by Reason, (2000). According to a Safety-I perspective an accident thus represents a situation or a condition where there is or was a lack of safety. Which immediately raises the obvious question of how it is possible to learn about something if it only is studied in situations where it is not there?No known sciences can do that-- except safety science!!! And furthermore how is it possible to manage something that is not there? The simple answer is that it is impossible! THE UNACCEPTABLE OUTCOMES THAT SAFETY MANAGEMENT FOCUS ON ARE THE RESULTS OF SOMETHING THAT HAPPENED IN THE PAST,BUT DOES NOT HAPPEN ANY LONGER IT CAN THEREFORE NOT BE MANAGED!!!-- While you can manage a process  you cannot manage a product.These paradox fortunately disappears in the view proposed by Safety-II, where safety is defined as a condition where as much as possible goes well. An acceptable outcome therefore represents conditions where safety is present rather than absent, and efforts are accordingly directed at understanding how this happens and how one can ensure that it will happen also in the future. Logically, if as much as possible goes well, then as little as possible goes wrong,since in practice something cannot go well and go wrong at the same time. A Safety-II approach therefore achieves the same objective as a Safety-I approach, but does so in a completely different way. In Safety-II the concern is not to manage safety as a static outcome, hence using safety as a noun but to manage system performance safely, as a dynamic process, hence safely as an adverb. There is a crucial difference between managing safety and managing safely. The former represents a cost, since the purpose is to avoid something rather than to achieve something, while the latter represents an investment that directly contributes to productivity as well as increased revenue. It is therefore clearly more important and useful for a company to manage safely than to manage safety.

Since most work and most activities in practice go well, even though we fail to pay attention to them there will also be more cases to study sand learn from. Best of all, perhaps is that there is no need to wait for something to happen, i.e., to fail or go wrong. Something is happening all the time all we need to do is to pay attention to it

Reason, J. (2000). Safety paradoxes and safety culture. Injury Control & Safety Promotion, 7(1), 3-14.