3.1 Theories/Models and Use of Loss Causation Techniques (사고발생이론의 이해)- 1
◈ Accident/Incident Ratio Studies - 사고 비율에 대한 연구
The actual figures vary between the different accident triangles but the important thing to note is that, for every major incident or fatality, there are many more less serious r near-miss incidents.
하인리히(Heinrich)의 1:29:300 법칙이 잘 알려져있지만 이 외에도 여러 사람/기관들에 의한 사고 비율에 대한 연구 사례가 있습니다.
◈ Domino and Multi-Causality Theories
The domino theory presents a simplified model, which considers only one cause of an accident. Also, in the Heinrich model, the focus is on immediate rather than root causes. Both models are highly reactive and cannot be used to predict the likelihood of accident.
사고발생이론에는 Domino 이론과 Multi-Causality 이론이 있는데 Domino(도미노) 이론은 사고발생 과정 중 한 가지의 원인에 대해서만 고려를 합니다. 특히 하인리히 도미노 이론은 root cause 보단 immediate cause에만 집중을 하게 되는데 이렇게 사고발생 과정 중 한 가지의 원인만 제거하면 사고의 발생을 막을 수 있을 것이라는 식의 접근은 상당히 수동적인 방식이며 사고의 발생을 예측하는데 한계를 가지고 있습니다.
◈ Single Cause Domino Theory
1) Heinrich's Accident Sequence
우리가 일반적으로 알고 있는 하인리히 도미노 이론 입니다.
According to Heinrich:
"A preventable accident is one of five factors in a sequence that results in an injury. The injury is invariably caused by an accident and the accident in turn is always the result of the factor that immediately precedes it."
| Accident Factors | Description |
| 1. Ancestry and social environment (선천적/사회환경적 요소) |
Reclessness, stubbornness, greed and other undesirable traits of character that may be passed along through inheritance. |
| 2. Fault of person (개인의 결함) | Inherited or acquired faults of person such as recklessness, violent temper, nervousness, excitability. These constitute reasons for committing unsafe acts or for the existence of mechanical or physical hazards. |
| 3. Unsafe act and/or mechanical or physical hazard (불안전한 행동/기계적, 물리적 위험) |
Unsafe performance of persons such as: standing under danger areas, careless starting of machines, removal of safeguards and horseplay; mechanical or physical hazards such as unguarded gears or points of operation, insufficient light, which result in accidents. |
| 4. Accident (사고) | Events such as falls of persons, striking of persons by flying objects, etc. are typical accidents which cause injury. |
| 5. Injury (상해) | Fractures, lacerations, etc. are injuries which result directly from accidents. |
In the case of the accident sequence, perhaps the easiest factor to eliminate is Number 3, the "unsafe act and/or mechanical or physical hazards".
2) Bird and Loftus theory
Bird and Loftus extended Heinrich's theory to take into account the influence of management in the cause and effect of accidents, suggesting a modified sequence of events:
① Lack of control by management
② This permits the existence of basic causes (i.e. personal and job factors)
③ In turn, this leads to immediate causes (such as substandard practices, conditions or errors)
④ These are subsequently the direct causes of the accident.
⑤ Finally, this results in loss (which may be categorised as negligible, minor, serious, or catastrophic)