Sunil Nair successfully defended his PhD

On Friday, the 27th March 2015, Sunil Nair defended his PhD thesis titled “Characterization of Safety Evidence for Assessment and Certification of Critical Systems”. The defense took place at 13.15, in Storstua, Simula Research Laboratory, Oslo.

In many domains such as avionics, railway and automotive, software-based systems need to be certified or assured for safety so that the failure of such systems do not cause undue risk to the user, public or the environment. Deeming a system to be safe involves gathering convincing evidence to argue the safe operation of the system, usually according to the requirements of some safety standard.

Nair’s thesis is aimed at understanding and characterizing the safety evidence information used for certification and assessment of safety-critical system. The thesis analyses the current state-of-the-art and state-of-the-practice on evidence management focusing specifically on what information contributes as evidence for safety, how is evidence structured and assessed and how is confidence on the evidence documented by human experts. As a result of the analysis, the thesis presents (1) a taxonomical classification of various evidence types, (2) a glossary of development and verification artifacts that contribute to each category, (3) a detailed traceability information model for safety evidence showing the various elements that characterize the evidence, and finally (4) a novel approach and tool support for assessing confidence in safety evidence by explicitly documenting the various reasons for establishing confidence while accounting for uncertainty.

The thesis is written within the field of Software Engineering. The work has been conducted at Simula Research Laboratory and has been developed in the scope of OPENCOSS, a large-scale European research project whose goal is to devise a common certification framework for the automotive, avionics, and railway domains.

Prior to the defense, at 10.15, Nair presented his trial lecture on the topic “The challenges of security assessment in critical systems”.

The adjudication committee

  • Dr. Steve Riddle, Center of Software Reliability, School of Computing Science, Newcastle University, UK
  • Prof. Andreas Lothe Opdahl, Semantic and Social Information Systems, Department of Informatics and Media Studies, University of Bergen, Norway
  • Dr. Arne Maus, Programming and Software Engineering, Department of Informatics, University of Oslo, Norway

Chair of the disputation

  • Dag Langmyhr, Department of Informatics, University of Oslo, Norway


  • Prof. Tim Kelly, University of York
  • Dr. Jose Luis dela Vara, Simula Research Laboratory
  • Prof. Magne Jørgensen, Simula Research Laboratory