Heinrichs Domino Theory

Heinrich developed the original domino theory of accident causation in the late 1920s. Although written decades ago, his work in accident causation is still the basis for several contemporary theories. 

According to Heinrich s early theory, the following five factors influence all accidents and are represented by individual dominos  

Negative character traits leading a person to behave in an unsafe manner can be inherited or acquired as a result of the social environment 

Negative character traits are why individuals behave in an unsafe manner and why hazardous conditions exist 

Unsafe acts committed by individuals and mechanical or physical hazards are the direct causes of accidents 

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A classic incident theory is H.W. Heinrich s domino theory of causation, which has had a significant influence on practical incident investigation. (2) Many adaptations of Heinrich s original proposal have been developed by later researchers. Heinrich labeled his five dominoes as follows ... 

Heinrich s approach is to identify, evaluate, and work on the middle dominoes, not just the last one or two dominoes in the line. The domino theory has significant limitations. The basic assumption is that there is a linear relationship between causation and progression. In other words, one occurrence follows another and ends in an incident. In the context of process-related incidents, this assumption is not always valid. Often parallel occurrences coincide to result in an incident rather than occurring as purely sequential occurrences. Nevertheless, the domino theory can provide a useful conceptual framework for simple incidents. 

The origin of the Domino Theory is credited to Herbert W. Heinrich, circa 1931, who worked for Travelers Insurance. Mr. Heinrich nndertook an analysis of 75,000 accident reports by companies insnred with Travelers. This resulted in the research report titled The Origins of Accidents, which concluded that 88 percent of all accidents are caused by the unsafe acts of persons, 10 percent by unsafe physical conditions, and 2 percent are Acts of God. His analysis of 50,000 accidents showed that, in the average case, an accident resulting in the occurrence of a lost-time work injury was preceded by 329 similar accidents caused by the same unsafe act or mechanical exposure, 300 of which produced no injury and 29 resulted in minor injuries. This is sometimes referred to as Heinrich s Law. Mr. Heinrich then defined the five factors in the accident sequence, which he identified as the Domino Theory. Heinrich s work is the basis for the theory of behavior-based safety, which holds that as many as 95 percent of all workplace incidents are caused by unsafe acts. See also Accident Chain Behavior-Based Safety. 

An incident evaluation tool to investigate causes leading to incidents and as a framework for incident investigation. It models the flow of actions that lead to an incident or loss (Figure L.4). It was originally developed by Herbert W. Heinrich and later modified by Frank Bird. See also Domino Theory. 

Finally, the two central points of the domino theory (i.e., Heinrich theory)... 

Heinrich produced some early thinking about accident prevention. He recognized the importance of unsafe acts and conditions and created a theory called the Domino Theory because Heinrich used a row of dominos to illustrate his theory. The theory states that an accident sequence is like a series of five dominos standing on end. One falling can knock the others over. The five dominos in reverse sequence are (1) an injury caused by (2) an accident, which, in turn, is caused by (3) unsafe acts or conditions. Causes for the latter are (4) undesirable traits (such as recklessness, nervousness, violent... 

Heinrich relied on some of these theories to form his Domino Theory of accident causation. See Chapter 3. Today, other methods describe how leaders impact work-related behavior and accident prevention. 

The two key points in Heinrich s domino theory are that (1) injuries are caused by the action of preceding factors, and (2) removal of the events leading up to the incident, especially employee unsafe acts or hazardous workplace conditions, prevents accidents and injuries. Heinrich believed that unsafe acts caused more accidents than unsafe conditions. Therefore, his philosophy of accident prevention focused on eliminating unsafe acts and the people-related factors that lead to injuries (Brauer, 1990). 

Figure 5-2. An illustration of Heinrich s Domino Theory of Accident Causation.

The first steps in being able to prevent accidents from propagating is to understand the combination of factors that can initiate them, and what causes them to escalate [Ontario 1999]. The generally accepted theories of accident causation, for example Heinrich s domino theory [Heinrich 1931] and Reason s organisational accident theory [Reason 1997] may use different terminology, but they do all have common themes ... 

The Domino Theory attributed to Heinrich is based on the theory that a chain or sequence of events can be listed in chronological order to show the events leading up to an accident ... 

The references can be fotmd below this list. Domino Theory (Heinrich, 1931)... 

In 1986, Frank Bird and George Germain [1] used Heinrich s [4] model to develop another accident causation model (Figure 12-8). This model used the same domino theory to show its key concepts of loss control. 

The domino theory of injuries listed five steps that lead to injury. In was first the environmental and social climate and ancestry that allowed the second step of human error to develop. This error in turn led to unsafe acts or mechanical and physical hazards. These acts or hazards then allowed an accident to occur, and then some accidents produced injury. Undesirable human traits such as nervousness were either inherited or created and exacerbated by their environment. These traits created human faults that then allowed unsafe acts such as not wearing protective gloves, or even engineered oversight of the need for machine guarding (Heinrich et al., 1980). Dr. Haddon was removing the fifth step of injury occurrence. Today s efforts of ergonomic control also attempt to remove the possibility of an error as well. 

In 1931, H.W. Heinrich published Industrial Accident Prevention. This work outlined his domino theory of accident prevention. Heinrich identified five factors that result in injury, and likened them... 

The quest for accident causes in the 1920s brought human fallibility into focus. Research showed that 88 per cent of the accidents were primarily caused by dangerous acts on the part of the individual worker (Heinrich, 1959). Heinrich applied an accident model (the Domino theory ), where the cause was related to the event that went wrong immediately before the occurrence of injury. These types of results followed from the central position that the human operator held (and still holds) in the control of industrial production processes. 

For accident mechanism theory, many domestic and foreign scholars and experts have done much research and put forward a lot of typical accident theory. Such as Domino accident model theory proposed by Heinrich in 1936, Energy transfer accident theory proposed by Gibson in 1961, then derived by Haddon in 1966, Gold mine accident model proposed by Lawrence in 1974, and so on. In domestic, Chen Baozhi put forward the two class of hazard point in 1995, Zhang Li put forward Human error accident model in Complex man-machine system in 1996, He Xueqiu put forward... 

Each of these multicauses is equivalent to the third domino in the Heinrich theory and can represent an unsafe act or condition or situation. Each of these can itself have multicauses and the process during accident investigation of following each branch back to its root is known as fault tree analysis. ... 

Heinrich advocated a multidisciplinary approach to safety, focused on engineering, psychology, management, and salesmanship. The emphasis on psychology supported his theory that the majority of accidents were caused primarily by the unsafe acts or behavior of employees— the axiom on which his prevention philosophy was based. This axiom was central to Heinrich s domino model of accident causation, which depicted five dominos lined up in a sequence. As we discussed in Chapter 12 (Figures 12-7 and 12-8), unsafe acts/conditions were placed in the central position, preceded by inherited or acquired personal faults, and followed by an inci-... 

In the 1920s, accident prevention was dominated by the domino sequence theory. At heart of this idea was a four-stage premise theorizing that injuries are caused by accidents, accidents are caused by unsafe acts of people or by exposure to improper mechanical conditions, these unsafe acts and conditions are a result of human faults, and that human faults are created by environment or inherited (Heinrich et al, 1980). In the application of this theory, the worker was the main concentration of effort and blame. It was the psychological focus, such as efforts to increase focus and compliance to rules and procedures, that dominated safety practice. 

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