The Definition and Assessment of a Safety Argument

That safety cases are gaining prominence in safety regimes and regulations is a claim that, nowadays, may go more or less unchallenged. In brief, a safety case intends to make an explicit and compelling case that a system under consideration is safe for its intended use. When understood in this sense, the notion of a safety argument becomes one of the key elements of a properly formulated safety case. Herein, in what may be seen as work in progress, we comment on some preliminary thoughts regarding the challenges one must face in order to provide an adequate and sensible definition of what would count as being a safety argument. We contend that, without such a definition, the assessment of a safety argument is well-nigh impossible.