.2 determine occurrence sequence;
.3 identify unsafe acts or decisions and unsafe conditions,
and then for each unsafe act or decision,
.4 identify the error type or violation;
.5 identify underlying factors; and
.6 identify potential safety problems and develop safety actions.
This process is detailed in appendix 1.
2.1.2 A systematic approach to step 1 is crucial to ensure that critical information is not overlooked or lost and that a comprehensive analysis can be made.
2.1.3 Step 2 involves organizing the data collected in step 1 to develop a sequence of events and circumstances.
2.1.4 In step 3, the information gathered and organized is used to initiate the identification of occurrence causal factors, i.e., unsafe acts, decisions or conditions. Once an unsafe act, decision or condition has been identified, the next stage is to determine the genesis of that particular act, decision or condition.
2.1.5 Step 4 is initiated in order to specify the type of error or violation involved in each identified unsafe act or decision.
2.1.6 In step 5, the focus is on uncovering the underlying factors behind the unsafe act, decision or condition. Fundamental to the process is the notion that for each underlying factor there may be one or more associated unsafe acts, decisions or conditions. The re-examination of each step of the process may show where further investigation is necessary.
2.1.7 Finally, step 6 requires the identification of potential safety problems and the proposing of safety action based on the identified underlying factors.
2.2 General consideration
An occurrence may result in serious injury, illness, damage or environmental impact and sometimes all four. The purpose of a marine casualty or occurrence safety investigation is to prevent recurrence of similar occurrences by identifying and recommending remedial action. All minor occurrences of high potential in terms of credible result should be subjected to a full investigation. Studies have shown that occurrences can have many causal factors and that underlying causes often exist remote from the incident site. Proper identification of such causes requires timely and methodical investigation, going far beyond the immediate evidence and looking for underlying conditions which may cause other future occurrences. Occurrence investigation should therefore be seen as a means of identifying not only immediate causes, but also failures in the total management of the operation from policy through to implementation. For this reason investigations should be broad enough to meet these overriding criteria.
