Levels of uncertainties

Abstract

Understanding different levels of uncertainty is important for a program, portfolio or project (PPP) manager as uncertainties can cause issues, confusion or discrepancies within PPP's. Most assessments of uncertainty is based on (potentially faulty and inadequate) assumptions, which can lead to poorly designed decisions. Understanding where the source of the uncertainty arises from can therefore aid the manager in understanding how to deal with them. Uncertainties are especially important to consider as they are often not quantifiable (and attempts to do so depends on other uncertainties that may be context based). This article seeks to highlight what different levels of uncertainties have been defined, from where they may arise, and how to manage them in a systematized manner. The article will/may contain:

BIG IDEA:

Uncertainties and Risks

• Definition of an uncertainty
• Definition of a risk
• The difference between the two
• 4 types of uncertainties (as proposed by Wynne, 1992)

Levels of Uncertainties

• The 5 levels of uncertainties (as proposed by Spiegelhalter and Riesch (2011))
  • event uncertainties
  • parameter uncertainties
  • model based uncertainties
  • acknowledged model based uncertainties
  • unknown inadequacies model based uncertainties

• And others distinctions (Walker (2003) on risk themes to consider (location, level, nature), van Assalt (2003) on types of uncertainties in climate governance, etc.)

APPLICATION

Managing uncertainties when they arise

LIMITATIONS

Limitations

Articles that are considered (not part of the abstract, will be considered but not for sure part yet, just here for reference):

“This Is What We Don't Know”: Treating Epistemic Uncertainty in Bayesian Networks for Risk Assessment

Risk and Uncertainty Communication

Walker, W. E., Harremoës, P., Rotmans, J., Van der Sluijs, J. P., Van Asselt, M. B. A., Janssen, P. & Krayer von Krauss, M. P. 2003 Defining uncertainty: a conceptual basis for uncertainty management in model-based decision support.

van Asselt, M. & Rotmans, J. 2002 Uncertainty in integrated assessment modelling. Clim. Change 54, 75–105. (doi:10.1023/A:1015783803445)

Wynne, B. 1992 Uncertainty and environmental learning: reconceiving science and policy in the preventive paradigm. Global Environ. Change 2, 111–127. (doi:10.1016/0959-3780(92)90017-2)

PMI standards for project, program and portfolio management

Handbook of Risk Theory: Epistemology, Decision Theory, Ethics, and Social Implications of Risk

The ambiguities of uncertainty: A review of uncertainty frameworks relevant to the assessment of environmental change (Bevan, 2022)

Don’t know, can’t know: embracing deeper uncertainties when analysing risks (Spiegelhalter, 2011)