Probability of failure | Target value | Impact potential | Risk of Harm (ROH) per tree per year | |
---|---|---|---|---|
Newcastle City Council assessment (2009) | 1/7.5 | 1/2.64 | 1/1 | 1/19.8 |
Mike Ellison assessment (2012) | ||||
Best tree | 1/100,000 | 1/20 | 1/1 | 1/2,000,000 |
Worst tree | 1/1,000 | 1/20 | 1/8.6 | 1/170,000 |