EFFECTIVE METHODS AND

PROCEDURES USED IN AN ACCIDENT INVESTIGATION

What is “accident”, “accident

investigation” and “purpose of

Accident investigation

WHAT IS AN “ACCIDENT”?

Accident is an unplanned undesirable event that interrupts a planned activity and that results in injury/illness or property damage

WHAT IS ACCIDENT INVESTIGATION?

An accident investigation is the analysis and account of an accident based on

information gathered by a thorough and conscientious examination of all factors

involved.

WHY DO COMPANIES DO ACCIDENT INVESTIGATION? Accidents are investigated in order to:

Prevent future incidentsTo identify and correct/eliminate unsafe

conditions, acts or proceduresReduce costs and down timeRegulatory requirementsProcess WCB claims

WHO CONDUCTS INVESTIGATION? Expert in accident causation

Are accidents caused by: Unsafe Acts or Unsafe Conditions?

experienced in investigative techniques fully knowledgeable of

work processesprocedurespersons and industrial relations

environment unbiased/impartial

Principles and process of accident

investigation

BASIC PRINCIPLES OF EFFECTIVE ACCIDENT INVESTIGATION accidents are generally rooted in

management system flaws or failures all accidents (or at least their outcomes)

are preventable investigations must be aimed at

identifying root causes proper investigative techniques investigative training

ACCIDENT INVESTIGATION PROCESS There are ten steps that add up to a thorough

and effective investigation.  They are: Understand the need for investigation Prepare for the investigation Gather the facts about the accident Analyze the facts Develop conclusions Analyze conclusions Make a report Make appropriate recommendations Follow through on recommendations Follow-up on corrective actions  

Understand the need for investigation The most important reason for conducting

investigations is that accidents indicate when something is wrong with the system of operating.

Uncovering the causes, and remedying the defects, can strengthen the operation, as well as eliminate future accidents.

Prepare For The Investigation The best way to handle accidents, when they do

occur, is to be prepared for them. After the unexpected happens, it is too late for

preparation; you need to make sure two areas are addressed. 

Gather The Facts: While the first two sections should be completed

well in advance of any actual accidents, the "gathering of facts" begins only when an accident/incident has actually taken place. It marks the beginning of the investigation itself.

The best approach is having a good plan, knowing the on-site priorities, and knowing where to start.

Analyze The Facts: This is an on-going process that begins when you

gather the first facts and begin mentally weighing them. This weighing of facts includes statements of witnesses and their credibility.

Develop Conclusions As the facts are gathered and analyzed,

conclusions can begin to be drawn about what happened and what caused it to happen.

This should be formally presented, with statements of conclusions and the relevant facts on which they were based, so that this is a matter of verifiable record. 

Analyze The Conclusions This analysis may refer either to a tentative or

partial conclusion, while still gathering facts, or to the final conclusions after all facts are known, weighed, and analyzed.

Make A Report The accident report should bring all this material together:

facts, analysis, and conclusions. The information has been gathered on the people involved, the

situation or specific incident. These facts have been reviewed and revised. Now all the information should be formalized into a report. Everything included in the report should be supported by facts

and evidence; unsubstantiated statements or mere speculations do not belong in the final report.

Make Appropriate Recommendations The best report in the world has failed if it merely states facts

and draws conclusions. Corrective actions are needed, and the report should

recommend them. Make specific recommendations indicating precisely what

should be done to correct the situation.

Follow Through On Recommendations Just the recommendations in the report are not

enough. The key word is action. Someone must demand action to keep the same or

a similar event from happening again. Someone in top management should insist that

corrective actions be taken as recommended and accountability take place. 

Follow-Up On The Corrective Action Review the corrective actions made. This step is essential at the end of the process, and

should continue to be evaluated on a less formal basis. 

Elements of Effective Incident Investigation

Procedures

The basic elements of an incident investigation report are as follows: Who was involved? What injuries were sustained? What property damage was sustained? Date and

Time of the incident Location of the incident Brief statement by the employee as to what

happened A cause analysis of the loss Corrective action to address the root cause of the

loss

Usefulness, Effectiveness and

Limitations of Accident Investigation

Usefulness:  As compared to non-systematic investigations,

methods of accident investigation based on a systematic concept have numerous advantages, which include the following: They allow the causal network of each accident to be

defined collectively, from which it is easier to devise new preventive measures and foresee their impact without being limited to the direct causes of the injury.

They provide those involved in the analysis with a richer and more realistic mental representation of the “accident phenomenon” that permits a global understanding of work situations.

In-depth accident investigations (especially when they are extended to cover incidents and undesired events) can become a means and appropriate occasion for dialogue between management and operators.

Effectiveness:  In order to be effective, accident investigation

requires that four conditions are satisfied concurrently: an evident commitment on the part of the top

management of the establishment, who must be able to ensure the systematic implementation of such procedures

training of the investigators management, supervisors and workers fully informed

concerning the aims of the investigation, its principles, the requirements of the method and the results expected

real improvements in safety conditions that will encourage those involved in future investigations.

Limitations: Even when carried out very well, accident investigation

suffers from a double limitation: It remains a procedure for investigating risks a posteriori (in

the manner of systems analysis), with the aim of correcting existing situations.

It does not therefore dispense with the need for a priori (prospective) investigations, such as the ergonomic investigation of jobs or, for complex systems, safety investigations.

The usefulness of accident investigations also varies with the safety level of the establishment where they are applied.

In particular, when the safety level is high (the accident rate is low or very low), it is evident that serious accidents result from the conjunction of numerous independent random factors that are relatively harmless from the safety viewpoint when considered outside the context under investigation.

Effectiveness of Preventive Measures

The effectiveness of a preventive measure can be judged with the help of the following criteria:

The stability of the measure The effects of a preventive measure must not disappear with time:

informing the operators (in particular, reminding them of instructions) is not a very stable measure because its effects are often transient. The same is moreover true of some protective devices when they are easily removable.

The possibility of integrating safety. When a safety measure is added on - that is, when it does not contribute

directly to production - it is said that safety is not integrated. Generally speaking, any preventive measure entailing an additional cost

for the operator should be avoided, whether it is a physiological cost (increasing the physical or nervous load), a psychological cost, a financial cost (in the case of salary or output) or even a simple loss of time.

The non-displacement of the risk Some preventive measures may have indirect effects that are detrimental

to safety. It is therefore always necessary to foresee the possible repercussions of a preventive measure on the system (job, team or workshop) in which it is inserted.

The possibility of general application (the notion of potential accident factor)  This criterion reflects the concern that the same preventive action may be applicable

to other jobs than the one affected by the accident under investigation. Whenever possible, an effort should be made to go beyond the particular case that

has given rise to the investigation, an effort that often requires a reformulation of the problems discovered.

The information obtained from an accident may thus lead to preventive action relating to factors that are unknown but present in other work situations where they have not yet given rise to accidents. For this reason they are called “potential accident factors”.

The effect on root “causes” As a general rule, the prevention of accident factors near to the point of injury

eliminates certain effects of dangerous situations, while prevention acting well upstream of the injury tends to eliminate the dangerous situations themselves.

An in-depth investigation of accidents is justified to the extent that the preventive action is equally concerned with the upstream factors.

The time taken for application The need to act as rapidly as possible after the occurrence of an accident so as to

avoid its reoccurrence is often reflected in the application of a simple preventive measure (an instruction, for example), but this does not eliminate the need for other more lasting and more effective action.

Every accident must therefore give rise to a series of proposals whose implementation is the subject of follow-up.

Accident problem solving techniques

PROBLEM SOLVING STEPS Accidents represent problems that must be solved

through investigations. Several formal procedures solve problems of any degree of complexity such as:

The Scientific Method The principle of agreement The principle of differences The principle of concomitant variation

Change Analysis Sequence Diagrams Gross Hazard Analysis Job Safety Analysis Failure Mode and Effect Analysis Fault Tree Analysis

THE SCIENTIFIC METHOD The scientific method forms the basis of nearly all problem

solving techniques. It is used for conducting research. In its simplest form, it involves the following sequence:

making observations developing hypotheses testing the hypotheses

The principle of agreement An investigator uses this principle to find one factor that

associates with each observation. The principle of differences

This principle is based on the idea that variations in observations are due only to differences in one or more factors.

The principle of concomitant variation This principle is the most important because it combines the

ideas of both of the preceding principles. In using this principle, the investigator is interested in the factors that are common as well as those that are different in the observations.

CHANGE ANALYSIS As its name implies, this technique emphasizes

change. To solve a problem, an investigator must look for deviations from the norm. As with the scientific method, change analysis also follows a logical sequence.

Use the following steps in this method: Define the problem (What happened?). Establish the norm (What should have happened?). Identify, locate, and describe the change (What,

where, when, to what extent). Specify what was and what was not affected. Identify the distinctive features of the change. List the possible causes. Select the most likely causes.

SEQUENCE DIAGRAMS Gantt charts are sequence diagrams.

Use them for scheduling investigative procedures. They can also aid in the development of the most probable sequence of events that led to the accident.

Such a chart is especially useful in depicting events that occurred simultaneously.

GROSS HAZARD ANALYSIS Perform a gross hazard analysis (GHA) to get a rough

assessment of the risks involved in performing a task. It is "gross" because it requires further study. It is

particularly useful in the early stages of an accident investigation in developing hypotheses.

A GHA will usually take the form of a logic diagram or table.

In either case, it will contain a brief description of the problem or accident and a list of the situations that can lead to the problem.

In some cases, analysis goes a step further to determine how the problem could occur.

A GHA diagram or table thus shows at a glance the potential causes of an accident.

One of the following analysis techniques can then expand upon a GHA.

JOB SAFETY ANALYSIS Job safety analysis (JSA) is part of many existing

accident prevention programs. In general, JSA breaks a job into basic steps, and

identifies the hazards associated with each step. The JSA also prescribes controls for each hazard. A JSA is a chart listing these steps, hazards, and

controls. Review the JSA during the investigation if a JSA

has been conducted for the job involved in an accident.

Perform a JSA if one is not available. Perform a JSA as a part of the investigation to determine the events and conditions that led to the accident.

FAILURE MODE AND EFFECT ANALYSIS Failure mode and effect analysis (FMEA) determines where

failures occurred. Consider all items used in the task involved in the

accident. These items include people, equipment, machine parts, materials, etc.

In the usual procedure, FMEA lists each item on a chart. The chart lists the manner or mode in which each item can

fail and determines the effects of each failure. Included in the analysis are the effects on other items and

on overall task performance. In addition, make evaluations about the risks associated

with each failure. That is, project the chance of each failure and the severity of its effects.

Determine the most likely failures that led to the accident. This is done by comparing these projected effects and risks with actual accident results.

FAULT TREE ANALYSIS Fault tree analysis (FTA) is a logic diagram. It shows

all the potential causes of an accident or other undesired event.

The undesired event is at the top of a "tree." Reasoning backward from this event, determine the circumstances that can lead to the problem.

These circumstances are then broken down into the events that can lead to them, and so on.

Continue the process until the identification of all events can produce the undesired event.

Use a logic tree to describe each of these events and the manner in which they combine.

This information determines the most probable sequence of events that led to the accident.

Conclusion

CONCLUSION Accidents result from a failure of people, equipment, supplies,

or surroundings to behave as expected. A successful accident investigation determines not only what

happened, but also finds how and why the accident occurred. Investigations are an effort to prevent a similar or perhaps

more disastrous sequence of events. Most accident investigations follow a research technique

called the scientific method. This method involves gathering and analyzing facts, and developing hypotheses to explain these facts.

Each hypothesis must be tested against the facts, and the most probable explanation of the accident needs to be selected. Any one of several problem solving techniques based on this approach may be used. An investigation is not complete however, until completion of a final report. Responsible officials can then use the resulting information and recommendations to prevent future accidents.

REFERENCES: http://

www.labtrain.noaa.gov/osha600/refer/menu16a.pdf

http://cmrris.com/news-manufacturing-details/23/ten-step-accident-investigation-process.html-       

Accident Investigation: OSH Answers. (2006). Retrieved April 6, 2012 from http://www.ccohs.ca/oshanswers/hsprograms/investig.html

OSHA Instruction CPL 2.89, Incorporating the Family of Accident or Illness Victims into the Fatality Investigation.

OSHA Instruction STP 2.22A, May 14, 1986, State Plan Policies and Procedures Manual.