Assumption-based Thinking for Risk Assessment

Dikmen Toker İ.

16th Engineering Project Organisation Conference, Pula, Croatia, 25 - 27 June 2018, pp.805-816

  • Publication Type: Conference Paper / Full Text
  • City: Pula
  • Country: Croatia
  • Page Numbers: pp.805-816


It has been widely acknowledged that risk assessment based on P-I ratings, has its limitations in that it does not in general capture hidden factors behind the risk ratings, mainly the “assumptions” and “background knowledge”. In this paper, it is argued that utilization of assumption-based thinking may improve risk assessment process by revealing assumptions behind risk evaluations. The illustrative case study about a mega project in Turkey demonstrates that some of the critical risk factors may be excluded from detailed analysis due to invalid assumptions. A method for assumption-based risk assessment is proposed as well as a sample format for an assumption log. Matching risks with assumptions has a potential to improve the reliability of risk ratings and updating risk management plans by checking validity of load-bearing and vulnerable assumptions.

This paper presents some of the initial ideas of an on-going research project about assumption-based risk assessment.  The proposed method will be tested on real projects to explore whether it has a potential to improve quality of risk-based decisions.