Development of Structured Arguments for Assurance Case

The paper describes an approach to improve Assurance Case applicability through structured argumentation. We started from approach based on use of twice argumentation step including reasoning step and evidential step with structured text support. After that, we improve the existing method with the following issues: (1) a general algorithm for the development of the Assurance Case is proposed; (2) relations between the argumentation graph and templates of structured text are explicitly explained; (3) structured text is supplied with clear templates. We implement a case study applying the obtained method for arguing functional safety compliance. A general conclusion is this method makes Assurance Case methodology more practical and understandable.