保証ケース（assurance case/dependability case）に関する
Ewen Denney (NASA Ames Research Center)
Towards Automation in Assurance Cases
Safety assurance cases have been in use for some time in the defense,
rail, and oil & gas sectors. Increasingly, they are being adopted for
safety assurance in other safety-critical domains, such as aviation,
automotive systems, and medical devices. Effectively, safety cases
reflect an evidence-driven, argument-based approach to safety
assurance, and have become a key element in safety regulation.
Although safety cases marshal heterogeneous evidence, of which a
significant portion can include formal engineering artifacts, safety
cases themselves remain, largely, informal. Furthermore, in the
current practice, their creation, evolution and evaluation continues
to be a manually-driven process, with the available set of tools
providing little to no support for automation.
We believe that (i) a more formal foundation for safety cases will
affirm their role as essential, first-class, safety engineering
artifacts, and (ii) given a formal basis, that much can be
In this talk, we present some of the issues involved in moving
towards a more formal, automated approach for safety case
development, and how some of these have been addressed in our toolset
for assurance case automation, AdvoCATE. We illustrate this with
several examples from the Unmanned Aircraft domain.
Yutaka Matsuno (The University of Electro-Communications)
A Design and Implementation of an Assurance Case Language
Assurance cases are documented bodies of evidence that provide valid and convincing arguments that a system is adequately dependable in a given application and environment. Assurance cases are widely required by regulation for safety-critical systems in the EU. There have been several graphical notation systems proposed for assurance cases. GSN (Goal Structuring Notation) and CAE (Claim, Argument, Evidence) are such two notation systems, and a standardization effort for these notation systems have been attempted in OMG (Object Management Group). However, these notation systems have not been defined in a formal way. This paper presents a formal definition of an assurance case language based on GSN and its pattern and module extensions. We take the framework of functional programming language as the basis of our study. The implementation has been done on an EclipseTM based GSN editor. We report case studies on previous work done with GSN and show the applicability of the assur!
ance case language.
Also, if there is time, I will introduce our assurance case activity called “D-Case project” in Japan (http://www.dcase.jp).
Keywords-Assurance Cases, GSN (Goal Structuring Notation), Functional Programming Languages