Conducting an Accident Investigation
Course 102
Safety Certified Supervisor Series

MODULE 5: DETERMINING SURFACE AND ROOT CAUSES

Event Analysis

In the last module we learned that each event in our sequence will include descriptions of actors and their actions that may have contributed to the accident.

Our next step is to examine each event to determine the hazardous conditions and unsafe or inappropriate behaviors representing the surface causes for the incident or accident:

1. the actor represents a hazardous condition, and
2. action that represents an unsafe or inappropriate behavior.

What techniques can we use to help us do the event analysis? Let's take a look at one technique that I have found efficient in conducting an event analysis.

I've modified the commonly used "fishbone diagram," used successfully by many as a general problem solving tool, to help conduct an event analysis.

1. Get a sheet of paper.
2. At the top of the sheet write "Accident Analysis". Doing this reminds you that you're breaking down the process into a number of events.
3. At the left side of the sheet, centered, write "The Injury".
4. Extend a horizontal line out from the right of the box.
5. Describe the injury event on the horizontal line.
6. Identify and circle the actors and actions described in the event statement.
7. Start asking why questions about the actor and actions to uncover any hazardous conditions or unsafe behaviors.
8. Draw lines either angling up or down from the circled actors and actions and write the answers to your questions.
9. Repeat these steps with each of the new level of answers.

The diagram you produce using this procedure should look something like this. Each level of questioning will get you closer to the root cause(s) that allowed the hazardous condition or unsafe behavior.