Quantitative and qualitative arguments

The approach used in the book is to assume that the safety case argues quantitatively, because this provides the simplest argument structure, with the most straightforward arguments, for ease of discussion. However, it is recognised that this is unrealistic, and that the Safety Case Report will probably contain a mixture of qualitative and quantitative arguments from the safety case at various points throughout the arguments.

The format provides a section to allow the project’s approach to this issue to be described and justified.

Hence, whilst the guidance in the book is defined in terms of quantitative arguments, it can equally be used with qualitative arguments (or a mixture or qualitative and quantitative).