Integrating analyses of the risk of occupational accidents into the design process — Part II: Method for prediction of the LTI-rate

In part I of this paper, combinations of types of acceptance criteria and risk analysis methods applicable to the field of occupational accidents were reviewed. It was concluded that there is a general lack of risk analysis methods for use in combination with quantitative acceptance criteria based on standard risk measures such as the lost-time in jury frequency rate. Part II outlines a risk analysis method, Comparison analysis. The method has been developed for use in evaluations of design concepts of offshore installations and predicts the lost-time injury frequency rate during the operational phase. Results and experience from a comparison analysis that was performed during the design of a drilling rig are presented and evaluated in relation to the requirements of the Norwegian Risk analysis regulations for the offshore industry. The results are also compared to operational experience during the two first years of operation. It is concluded that comparison analysis meets the different formal requirements of the Risk analysis regulations. There are potentials of improvements through stricter definitions of decision rules and assumptions to be used in performing the analysis.