scores ranging from 1 to 25 (Figure 6). From these risk ratings, the hazards were ranked for each group, from highest priority to lowest. Any uncertainty surrounding the subjective scores was explicitly incorporated by allowing groups to place bounds on their estimates if they wished (e.g. consequence, moderate to major). This was carried through to the risk rating calculation by the use of interval arithmetic (e.g. likelihood 3 to 5 and consequence 2 to 3 results in risk rating 6 to 15). Figure 6 Risk scores as the product of likelihood and consequence scores. The level of agreement between pairs of groups was then measured using Spearman's rank correlation, where +1 indicates perfect agreement in rank order, -1 perfect disagreement, and values around 0 indicate no particular pattern between the two sets of ranks. The use of a specialised computer program "Subjective Risk Assessment" (Chisholm et al. 2005), allowed rapid calculation and display of risk scores and rank correlations for all pairs of groups. With a view to identifying and possibly resolving of some types of disagreement, the correlations and the likelihood and consequence scores were examined to identify major disagreements, and selected hazards were discussed in detail. There was no demand for consensus in the ranking process, the aim being to acknowledge and retain genuine differences of opinion. Following the discussion, groups had the opportunity to revise their likelihoods and consequences if they wished. Any changes were then entered in the ranking software and the risks and ranks recalculated. The risk posed by each hazard was recorded in the risk register, where the range of values for likelihood, consequence and risk for each hazard reflected the final range of opinion among the groups of participants. Risks were also categorised on a four-point scale in accordance with AS/NZS 4360 (SA/SNZ 1999) for consistency with previous Parks Victoria practice (Figure 7). Note that there is no simple conversion from the 25-point risk rating scale used here (Figure 6) to the four risk categories.
scores ranging from 1 to 25 (Figure 6). From these risk ratings, the hazards were ranked for each group, from highest priority to lowest. Any uncertainty surrounding the subjective scores was explicitly incorporated by allowing groups to place bounds on their estimates if they wished (e.g. consequence, moderate to major). This was carried through to the risk rating calculation by the use of interval arithmetic (e.g. likelihood 3 to 5 and consequence 2 to 3 results in risk rating 6 to 15). Figure 6 Risk scores as the product of likelihood and consequence scores. The level of agreement between pairs of groups was then measured using Spearman's rank correlation, where +1 indicates perfect agreement in rank order, -1 perfect disagreement, and values around 0 indicate no particular pattern between the two sets of ranks. The use of a specialised computer program "Subjective Risk Assessment" (Chisholm et al. 2005), allowed rapid calculation and display of risk scores and rank correlations for all pairs of groups. With a view to identifying and possibly resolving of some types of disagreement, the correlations and the likelihood and consequence scores were examined to identify major disagreements, and selected hazards were discussed in detail. There was no demand for consensus in the ranking process, the aim being to acknowledge and retain genuine differences of opinion. Following the discussion, groups had the opportunity to revise their likelihoods and consequences if they wished. Any changes were then entered in the ranking software and the risks and ranks recalculated. The risk posed by each hazard was recorded in the risk register, where the range of values for likelihood, consequence and risk for each hazard reflected the final range of opinion among the groups of participants. Risks were also categorised on a four-point scale in accordance with AS/NZS 4360 (SA/SNZ 1999) for consistency with previous Parks Victoria practice (Figure 7). Note that there is no simple conversion from the 25-point risk rating scale used here (Figure 6) to the four risk categories.
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