You've completed the initial of the accident analysis by gathering information and using it to break the accident down into an accurate sequence of events. You have a good mental picture of what happened. Now it's time to continue the analysis process by completing each of the following three phases of analysis to determine what caused those events. This module will introduce us to the three phases of analysis below:
Check out this short audio clip by Dan Clark of the theSafetyBrief.com. Folklore that “accidents happen” has been proven wrong. But are people naturally accident prone? In this podcast, Dan Clark delves into these topics.
As mentioned earlier in the course, accidents are processes that culminate in an injury or illness. An accident may be the result of many factors (simultaneous, interconnected, cross-linked events) that have interacted in some dynamic way. In an effective accident investigation, the investigator will conduct three levels of cause analysis:
Injury analysis: At this level of analysis, we do not attempt to determine what caused the accident, but rather we focus on trying to determine how harmful energy transfer caused the injury. Remember, the outcome of the accident process is an injury.
Surface Cause Analysis: Here you determine the hazardous conditions and unsafe behaviors described in the sequence of events that dynamically interact to produce the accident. The hazardous conditions and unsafe behaviors uncovered are the surface causes for the accident and give clues that point to possible system weaknesses.
Root cause analysis: At this level, you're analyzing the weaknesses in the safety management system that contributed to the accident. You can usually uncover weaknesses related to inadequate safety policies, programs, plans, processes, or procedures. Root causes always pre-exist surface causes and may function through poor component design to allow, promote, encourage, or even require systems that result in hazardous conditions and unsafe behaviors. This level of investigation is also called "common cause" analysis (in quality terms) because you're identifying a system component that may contribute to common conditions and behaviors that exist or occur throughout the company.
One last important point to make is that most accident processes are far more complex than you might originally think. Some experts believe at least 10 or more factors come together to cause a serious injury accident. Other experts state that an average of 27 factors directly and indirectly contribute to a serious accident.
Only by thoroughly conducting all three levels of analysis can you design system improvements that effectively eliminate hazardous conditions and unsafe behaviors at all levels of the organization. The accident investigation can not serve as a proactive safety process unless system improvements effectively prevent future accidents.
It's important to understand that all injuries to workers are caused by one thing: the harmful transfer of energy. Let's take a look at some examples that illustrate this important principle.
In the next section, we'll take a closer look at each of the types of energy that might cause injury.
The important point to remember here is that the "direct cause" of the injury is not the same as the "surface cause" of the accident event.
Injuries always somehow result in the transfer of a harmful level of energy to a person's body. The severity of the injury depends on the magnitude of the harmful energy. Below are the various forms of energy that can be harmful.
In the last module, you learned that each event in our sequence will include an actor and an action that may have contributed to the accident. Once we have identified the actors and actions in the sequence of steps, our next job is to conduct an event analysis to determine the surface causes for the accident.
The surface causes of accidents are those hazardous conditions and unsafe or inappropriate behaviors within the sequence of events that have directly caused or contributed in some way to the accident.
Hazardous conditions may exist in any of the categories below.
It's important to know that most hazardous conditions in the workplace are the result of the unsafe or inappropriate behaviors that produced them.
Below are some examples of unsafe or inappropriate employee/manager behaviors.
We recommend using both the "5-Why Analysis" and "Fishbone Diagram" to help you conduct an event analysis to uncover surface causes. Follow the steps below to conduct a Fishbone Diagram:
The diagram you'll produce using this procedure should look something like the diagram to the right. In fact, it will probably look more complex. Each level of questioning will get you closer to the root cause(s) that contributed to the hazardous conditions or unsafe behaviors. Ultimately, you'll start identifying inadequate policies, programs, plans, processes, procedures and practices (the 6P's): you're getting to the real root causes!
Now let's switch gears. Instead of talking about unique conditions and behaviors, let's take a look at analyzing the surface causes to determine possible safety management system weaknesses. There are many "general" conditions and behaviors (variables) inherent in the safety management system. Oh yes... to me the safety management system is "organic". By that I mean it is dynamic, ever-changing and behaves as though it were alive. Think about it. If that's a little too metaphysical for you... read on.
The root causes for accidents are the underlying safety management system weaknesses, which consist of thousands of variables, any number of which can somehow contribute to the surface causes of accidents. These weaknesses can take two forms.
Safety managers should work with safety engineers to eliminate or reduce exposure to hazards through effectively improving safety system components. Because systems design work common throughout the workplace, eliminating any single root cause may simultaneously eliminate many hazardous conditions and unsafe behaviors.
Since root causes reside within safety management systems, upper management -- those who formulate systems, are most likely going to be involved in making the necessary improvements. When analyzing for system weaknesses, it may be beneficial to coordinate closely with those who will be responsible for implementing system improvements.
Take a look at the Accident Weed, an excellent analogy that helps us understand the relationship between surface and root causes for accidents.
Finally, according to SAIF Corporation in Oregon, most accidents in the workplace result from unsafe work behaviors.
These statistics imply that management system weaknesses contribute in some way for fully 98% (conditions + behaviors) of all workplace accidents. So, ultimately, most accidents are the result of safety management system weaknesses.
To effectively fulfill your responsibilities as an accident investigator, you must not close the investigation until these root causes and solutions have been identified.
Whew! That was a lot to take in. Time for the quiz!
Before beginning this quiz, we highly recommend you review the module material. This quiz is designed to allow you to self-check your comprehension of the module content, but only focuses on key concepts and ideas.
Read each question carefully. Select the best answer, even if more than one answer seems possible. When done, click on the "Get Quiz Answers" button. If you do not answer all the questions, you will receive an error message.