The most important word in the above risk acceptance criteria is ‘effective.’ Effectiveness should be based on demonstrated performance. Where barriers and controls depend on human actions, they should be complemented by training and competence assurance processes.
Bow ties not only assist in proactively establishing the barriers, controls, and recovery measures nec-essary to manage risks, they offer a frame of reference for understanding how hazardous events (inci-dents and accidents) occur and for refining the barriers, controls, and recovery measures to prevent recurrence. Used in this way, bow ties can be continuously improved with experience.
Several points should be considered in evaluating opportunities to reduce risks including, codes and standards, best practices, expert judgment, risk based analysis (e.g., quantitative risk assessment), company values, and societal values. The UKOOA publication, Industry Guidelines on a Framework for Risk Related Decision Support gives an excellent description of how these factors should be considered in various decision contexts.
ISO 17776:2000 Petroleum and Natural Gas Industries – Offshore Production Installations – Guidelines on Tools and Techniques for Hazard Identification and Risk Assessment is also a useful industry specific reference document.
In addition to these guidelines, to ensure that money is spent where it will do the most good when faced with multiple risk reduction opportunities and insufficient funds to do them all, the opportu-nities should be ranked according to the benefit, cost, and effort required to implement.
The figure below depicts the process whereby benefit, cost, and effort estimates produce a ranking between 1 and 27, with 1 being the most beneficial, least expensive and most easily implemented opportunity.
Take score on cost/benefit scale & multiply with effort
Benefit Effort Score
HML
Cost
L
1 2 3
2 4 6
3 6 9
1 2 3
From
M
1 to 27
H
Benefit, cost, and effort scores are given values of 1, 2, or 3 based on objective and logical criteria. For example, costs of less than $50,000 might be assigned a 1, costs between $50,000 and $100,000 a 2, and costs over $100,000 assigned a 3. The actual values should be set to make rational distinctions between the least and most expensive risk reduction opportunities. The same logic should be used to assign values of 1, 2, or 3 for the benefit and the effort associated with each opportunity. The final ranking number is the product of the benefit, cost, and effort values. An opportunity with high benefit, low cost, and low effort values will yield a ranking number of 1. An opportunity with low benefit, high cost, and high effort values will yield a ranking number 27.
While the above described process helps to rank risk reduction opportunities, it is not intended to override the judgements based on UKOOA’s Industry Guidelines on a Framework for Risk Related Decision Support, which might dictate that all the risk reduction opportunities be employed. When on the other hand, it is not clear where to draw the line on the rank-ordered list of risk reduction opportunities, a plot like the one shown below can produce informed and healthy debate.
Risk Mitigation
Risk Reduction Opportunities
The ultimate test in the evaluation of risk reduction opportunities is the ‘red face test’. If there was an accident caused by the lack of a risk reduction measure that you or your company chose not to employ, could you and your company’s senior management stand before the press or a court of law and explain your choices without having a red face from embarrassment?
Note that quantifying the financial losses likely to result from the lack of a safety feature and com-paring that to the cost of the safety feature is highly discouraged. Ford Motor Company once did such an analysis and predicted that the cost of the deaths likely to result from fuel tank fires after rear-end collisions was less than the cost of the putting rubber bladders in the fuel tanks of its Pinto car model to prevent fuel release after rear-end collisions. In one class-action lawsuit alone, Ford was forced to pay over $1 billion in damages. There could be great liability consequences for any company that knowingly and wilfully fails to take affordable safety measures that have proven effectiveness.
中國航空網(wǎng) www.k6050.com
航空翻譯 www.aviation.cn
本文鏈接地址：飛機(jī)管理指南 Aircraft management guidelines(64)
