RA Limitation

Limitation in Risk Assessment

When using the QRA results for decision making purposes or when chartering a QRA Study, we must recognise and respect the limitation in risk assessment due to the fact that quantitative risk analysis is subject to several theoretical limitation lists.

Completeness	There can never be a guarantee that all accident situations, causes, and effects have been considered
Model Validity	Probabilistic failure models cannot be verified. Physical phenomena are observed in experiments and used in model correlations, but models are, at best, approximations of specific accident conditions
Accuracy/Uncertainty	The lack of specific data on component failure characteristics, chemical and physical properties and phenomena severely limit accuracy and can produce large uncertainties
Reproducibility	Various aspects of QRA are highly subjective-the results are very sensitive to the analysts assumptions. The same problem, using identical data and models, may generate widely varying answers when analyzed by different experts
Skill Unavailable	The accuracy and corresponding uncertainty of a risk estimate depend heavily upon the expertise and judgement of the analyst
Inscrutability	The inherent nature of QRA makes the results difficult to understand and use