accident investigation unit V assignment

BOS 4601, Accident Investigation 1

Course Learning Outcomes for Unit V Upon completion of this unit, students should be able to:

3. Apply accident investigation techniques to realistic case study scenarios. 3.1 Develop a barrier analysis chart and worksheet for an accident investigation.

4. Evaluate analytical processes commonly used in accident investigations.

Reading Assignment Chapter 8: Change Analysis Chapter 9: Barrier Analysis In order to access the resources below, you must first log into the myCSU Student Portal and access the Business Continuity & Disaster Recovery Reference Center database within the CSU Online Library. Kongsvik, T., Haavik, T., & Gjøsund, G. (2014). Participatory safety barrier analysis: A case from the offshore

maritime industry. Journal Of Risk Research, 17(2), 161-175. Pranger, J. (2009). Selection of incident investigation methods. Loss Prevention Bulletin, 2009(209), 1-12.

Unit Lesson In the previous unit, we learned that documenting the sequence of events that led up to an accident is critical to the accident investigation process. When conditions surrounding each event are added to the timeline, potential causal factors begin to emerge. However, an events and causal factors chart by itself may not be enough to identify all causal factors. It is a best practice to use more than one analysis technique during an accident investigation. Every technique has some limitations, and using multiple techniques will improve the reliability of the investigation conclusions (Oakley, 2012). In this unit, we examine two analytical techniques: change analysis and barrier analysis. Both are simple to use, and both can provide significant insight into answering the question of why an accident happened. Change analysis is used to determine if there was a change in procedures or conditions that led to an accident. This is done by comparing the accident sequence (which we have already determined using an events and causal factors chart) to a sequence for the task where an accident did not occur, to a set of procedures that say how the task should be performed, or to an imagined “ideal” sequence (Oakley, 2012). Routine and repetitive tasks are good candidates for this analytical technique. Change analysis is useful as long as there is an accident-free situation that can be used for comparison. The changes between an accident sequence and an accident-free sequence can be subtle and easily overlooked. One of the potential weaknesses of change analysis is that it might lead some investigators to place blame for changes on the workers. Not all “changes” are caused by the workers. For example, the temperature may have been warmer in the accident sequence than in the accident-free sequence, or perhaps a new, unfamiliar product was being handled. It is best to use change analysis in concert with one or more additional analysis techniques.

UNIT V STUDY GUIDE

Analytical Techniques I

BOS 4601, Accident Investigation 2

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Barrier analysis looks at the barriers that should have, or could have, allowed the hazard to reach the target (Oakley, 2012). Barriers are control functions that are designed to stop the accident sequence at one or more points. Note once again the importance of documenting the event sequence when conducting accident analysis. Barriers can be “hard,” like a machine guard or personal protective equipment, which will prevent physical contact with the hazard; however, barriers can also be “soft,” like training and written procedures, which, if followed, will prevent contact with the hazard. Barriers can be categorized into three main types, which are as follows (Oakley, 2012):

 barriers that failed,

 barriers that were not used, and

 barriers that did not exist. These categories will be helpful when we begin to identify corrective actions. Barriers that fail often correspond to engineering failures. Barriers not used may be the result of poor decision making or inadequate training. Barriers that did not exist often reveal flaws in the hazard identification and control process. Now, we need to return to the accident sequence presented in Unit IV, and we will use it for a brief demonstration of how change analysis and barrier analysis can be applied. On January 2, 2016, at 5:34 a.m., Sam, the night maintenance technician, noticed a leak in the water pipe in the valve department. The valve had been leaking for four months, but because a maintenance request had not been submitted, the problem was not fixed. Sam was about to clock out at 5:40 a.m. and decided to leave a note for Mary, the first shift technician, to mop up the area. At 5:53 a.m., an air horn was sounded for everyone to respond to an area. As workers arrived, they noted that Bob (another employee) was lying in a pool of water. It was very obvious to everyone that Bob’s leg was broken. An ambulance was called, and, at 6:00 a.m., Bob was transported to the hospital. During the investigation, it was learned that Sam had noted the water but decided not to clean the area immediately. Sam left a note at the desk at 5:41 a.m. and departed the area. Mary was supposed to clock in at 5:40 a.m., but she called her supervisor, Tom, at 5:33 a.m.; she was unable to talk to him, so she left a message that she would be arriving at 6:00 a.m. since she was running late. Tom, the supervisor, also called at 5:33 a.m., and he left a message for Mary, saying that he was running 15 minutes late. Mary, who arrived at 5:53 a.m., heard the alert horns and responded to the accident. To see the events and causal factors chart for this accident, click here. Change Analysis For demonstration purposes, we will use an ideal situation as our comparison accident sequence. We see that if there was no water on the floor, Bob would not have slipped and fallen. Of course, we need to look a bit further into the event sequence that resulted with the water on the floor. In an ideal situation, the leak would have been fixed when it was first discovered. In an ideal situation, Sam would have cleaned up the water when he noticed it. Finally, in our ideal situation, the communication between Tom and Mary could have been more effective. To see the change analysis chart for the accident, click here. We did not identify anything different than what we had included in the earlier events and causal factors chart, but the change analysis format provides a better opportunity to lead us to possible corrective actions. The analysis clearly shows responsibility at the worker, supervisor, and management levels. Barrier Analysis The hazard in our accident scenario is the water on the floor. The target is Bob, the injured worker. Our analysis needs to identify barriers that could have prevented Bob from coming in contact with the water. Brainstorming barriers might result in a list, such as follows:

 procedure requiring “wet floor” sign (administrative barrier – not used or does not exist);

 procedure requiring immediate spill cleanup (administrative barrier – not used or does not exist);

BOS 4601, Accident Investigation 3

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 supervisor training (administrative barrier – not used or does not exist); and

 maintenance procedures (administrative barrier – not used or does not exist). There are many ways to look at barriers. If we knew that a procedure requiring a “wet floor” sign did exist, then we could say it was an engineered barrier that was not used. An analysis is likely to change as more information is revealed. Root causes are discovered only after extensive investigative work. To see the barrier analysis chart for the accident, click here. The barrier analysis chart accomplishes the following: contains additional information discovered after the initial brainstorming of possible barriers, leads us directly to causal factors, and starts us on the path to possible corrective actions. Note that it also provides a bit more depth on causal factors than provided by the change analysis. Change analysis and barrier analysis are easy to use and, when used together, complement each other well. In the next unit, we will examine more techniques that can be used.

Reference

Oakley, J. S. (2012). Accident investigation techniques: Basic theories, analytical methods, and applications (2nd ed.). Des Plaines, IL: American Society of Safety Engineers.

Suggested Reading To learn more about conducting accident investigations, take a few minutes to read the report below. It explores some major methods of accident investigation that are being used, and it discusses the application of these methods. Sklet, S. (2002). Methods for accident investigation. Retrieved from

http://frigg.ivt.ntnu.no/ross/reports/accident.pdf This handbook, created by the U.S. Department of Energy, provides a sequential process for conducting accident investigations. The document assists in determining how and why an accident happened, and the document touches on how to develop conclusions to prevent the accident from happening again. U.S. Department of Energy. (2012). Accident and operational safety analysis: Volume I: Accident analysis

techniques. Retrieved from http://energy.gov/sites/prod/files/2013/09/f2/DOE-HDBK-1208- 2012_VOL1_update_1.pdf