All accidents, incidents, and near misses should be investigated. The focus of the investigation should be to identify the root cause. While there are many reasons for investigating accidents, the main reason is to keep similar accidents from happening again. Effective and thorough accident investigations show employees that their employer is concerned for their safety and well-being.

Except in relation to Process Safety Management (PSM), the Occupational Safety and Health Administration (OSHA) does not require employers to perform accident investigations. However, some states do require them, so be sure to understand any state laws and regulations. In addition, many insurance companies require accident investigations as a condition of coverage.

• Conclusions emerging from an accident investigation can be essential to preventing future accidents.
• Identifying root causes, exposing errors in processes, and correcting unsafe actions or procedures are among the key objectives of an accident investigation.

When an investigation is performed properly, the results can provide important information to help prevent future accidents. Breaking the chain of accident repetition is one of the most important reasons for accident investigations.

Showing concern for employees is another important aspect. Thorough investigations show employees that their employer is committed to providing a healthy and safe working environment. In contrast, poor accident investigations that only address what happened (or blame employees) may give employees the impression that the company doesn’t care about them.

Unfortunately, many employers and employees feel that the main reason for accident investigation is to find fault. Worse, supervisors may openly reprimand those involved in an accident in front of their peers. Employees may be suspended from work, reassigned to a different work area, or required to attend refresher training. Some employees may even be fired for being involved in an accident. Such consequences discourage interest and participation in the accident investigation. Participation can be encouraged, however, if employees understand the importance of accident investigations and the reasons for conducting an investigation.

Investigation objectives

To promote the need for accident investigations, it is a good idea to have some main objectives in mind. While there are more than four objectives, at least these four should always be considered:

1. Demonstrating to employees that their safety and well-being is of highest priority,
2. Examining the circumstances in which the accident occurred,
3. Determining what changes need to be made to correct the immediate problem(s) that appeared to have caused the accident, and
4. Analyzing the entire safety management process to prevent accidents and the recurrence of accidents.

Identifying root causes

Identifying root causes is the central purpose behind accident investigations. The goal should be to identify failures at a deep level in order to prevent not only a recurrence of the accident, but all potential accidents stemming from the same root cause.

Exposing errors in processes

Exposing errors in processes is an important part of the investigation because one or more errors may have played a part in the accident. The following list provides some examples of possible errors in processes:

• Lack of proper tools or equipment,
• Lack of guards or similar safety devices,
• Unsafe or defective equipment,
• Poor housekeeping,
• Improper use of tools or equipment,
• Lack of protective clothing and equipment,
• Inattention or neglect of safe practices,
• Lack of awareness of hazards involved,
• Improper training, or
• Failure to follow prescribed procedures.

Correcting unsafe acts and conditions

While investigating an accident, some unsafe conditions likely will be discovered. In addition to conditions that may have caused the accident, other conditions that may have contributed to the accident in some way might also be discovered.

The Occupational Safety and Health Administration (OSHA) requires employers to report any fatality, amputation, hospitalization, or loss of eye to the agency within prescribed time frames. Depending on the specifics of the case, OSHA will either perform an on-site inspection or conduct a Rapid Response Investigation (RRI).

During an RRI, OSHA asks employers to conduct a root cause analysis of the injury and report their findings to OSHA, along with steps taken or to be taken to correct the hazard and keep it from happening again.

If an employer conducts a thorough root cause analysis and implements findings, it is unlikely OSHA will then conduct an on-site inspection. However, if the employer does not respond adequately, an on-site inspection will likely be conducted.

• An OSHA standard mandates that employers investigate each incident that involved, or could have involved, a catastrophic release of highly hazardous chemical in the workplace.

Incident investigation is required under the Occupational Safety and Health Administration (OSHA) Process Safety Management (PSM) Standard at 1910.119. Employers covered by the standard must investigate each incident that resulted in, or could reasonably have resulted in, a catastrophic release of highly hazardous chemical in the workplace. The regulation requires employers to start an incident investigation as promptly as possible, but no later than 48 hours after the incident.

Employers must:

• Put together an investigation team,
• Prepare a report after the incident and keep it for five years, and
• Create a system to address recommendations and document corrective actions.

Form an incident investigation team

The incident investigation team must be made up of at least one person who understands the process involved in the incident. This person may be a contract employee if he or she is the person with the appropriate knowledge and experience to thoroughly investigate and analyze the incident.

Write a report

OSHA requires PSM-covered facilities to prepare a report at the conclusion of the investigation with the following information:

• Date of the incident,
• Date the investigation began,
• A description of the incident,
• The factors that contributed to the incident, and
• Recommendations resulting from the investigation.

Review the report with all employees whose job tasks are relevant to the incident findings, including contract employees where applicable.

Establish a system to address the hazards

After the investigation, the employer must implement a system to promptly address and resolve the incident report findings and recommendations. Resolutions and corrective actions must be documented.

Retain reports and other documentation for five years.

• Effective preplanning of an accident investigation is essential since relevant information quality and quantity begin to decline right after an accident.
• A well-trained team, a written plan, and a proper investigation kit can facilitate the accident investigation process.

Effective accident investigation starts before an accident by establishing a well-planned investigation procedure and a written plan. Preplanning is especially important because the quantity and quality of information begins to diminish immediately following the accident.

The accident investigation team should be organized before an accident happens so team members can be trained in accident investigation procedures. Assembling an accident investigation kit is also critical.

Organizing an investigation team

Organize an accident investigation team before an accident occurs so team members can become familiar with the investigation procedures. Team members should know how to:

• Respond to the accident scene before physical evidence is disturbed.
• Sample unknown spills, vapors, residues, etc., noting conditions that may have affected the sample.
• Prepare visual aids such as photos, field sketches, and other graphical representations with the objective of providing data for the investigation.
• Obtain information from eyewitnesses, if possible. Interviews with those directly involved and others whose input might be useful should be scheduled as soon as possible. Interviews should be conducted privately and individually so the comments of one witness will not influence the responses of others.
• Observe key mechanical equipment as it is disassembled.
• Review all sources of potentially useful information. These may include operating logs, previous reports, procedures, equipment manuals, oral instructions, design data, training records, and laboratory tests.
• Determine which accident-related items should be preserved. When a preliminary analysis reveals that an item may have failed to operate correctly or was damaged, arrangements should be made to either preserve the item or carefully document any subsequent repairs or modifications.
• Document the sources of information in the accident report. This will be valuable if further study of the accident becomes necessary.

Although team membership will vary according to the type of accident, a typical team investigating an operating area accident might include:

• A supervisor from the area where the accident occurred;
• Personnel from an area not involved in the accident;
• An engineering and/or maintenance supervisor;
• The safety supervisor;
• Occupational health/environmental personnel;
• Research and/or technical personnel; and
• Other appropriate personnel (i.e., operators, mechanics, or technicians).

Training the investigation team

Members of the accident investigation team should be trained to conduct an investigation. This includes interview techniques, writing reports, evaluating findings, estimating costs, and a host of other activities. Make the team aware of how the investigation reports will be used.

Developing a written plan

The preparation process includes developing a written plan. At a minimum, a written plan should contain the following types of information:

• A complete listing of the investigation team’s chain of command, including who will be in charge, gather physical evidence, take notes and photos, interview witnesses and victims, prepare the final report, and receive copies of the final report;
• A list of personal protective equipment (PPE) that will be needed; and
• A list of special transportation or communication needs.

Assemble a kit

The planning process also requires assembling equipment needed to perform investigative duties. This equipment should be contained in an accident investigation kit. Examples of basic equipment include:

• First-aid kit
• Barricade tape
• Reporting forms
• Photography/video equipment (including tripod if possible)
• Clipboard and notebook
• Tape
• Gloves (both work gloves and surgical gloves)
• Pens and pencils
• Chalk, crayons, or magic markers
• Sketching materials
• Large envelopes
• Measuring tape
• Scissors
• String
• Tags

• A specific series of procedures should be observed when conducting a proper accident investigation.

Conducting an effective accident investigation will involve the following steps:

• Control the scene. Correct any immediate hazards, secure the area, and preserve evidence. Hazards may include fallen electrical wires, fires, chemical spills, or other physical or health hazards. Providing personal protective equipment (PPE), isolating pressurized systems, and supplying emergency lighting helps ensure the safety of workers responding to the accident.
• Identify and collect evidence. Take pictures of the scene, take samples of spilled materials, interview witnesses, review health and safety records and training records, and consider operations errors such as unguarded or defective equipment, poor ventilation or lighting, toxic gases, excessive noise, radiation, or floor openings. This step includes taking notes that can help develop a final report.
• Mark and label all evidence: Evidence is anything that helps establish the facts. Label and mark the accident scene itself to warn others to stay away from the area while the accident is being investigated.
• Determine the root cause(s): Review all collected evidence and facts. The root cause is the true cause of the accident and is usually a system failure, not merely an employee action. For instance, if an employee injured in a fall was not wearing fall protection, one obvious factor is the failure to wear fall protection. However, if the employer did not consistently enforce the policy requiring fall protection, the root cause would be lack of enforcement. Other root causes can include lack of training, failure to maintain equipment, or lack of equipment guarding.
• Develop corrective actions. Work to reduce or eliminate the chances of another accident occurring. Corrective actions directly address the root cause.
• Communicate findings. Report the findings to upper management and other affected departments. To effectively communicate the findings, provide the following information in the final report:
  1. A description of the accident (including date, time, and location);
  2. The facts determined during the investigation (including chronology as appropriate);
  3. A list of the suspected root causes; and
  4. Recommendations for corrective action (including timing and responsibility for completion).
• Implement corrective actions. Ensure the corrective actions developed are actually carried out.

• Responding to an incident and securing the scene involve prompt actions and assessing priorities.

People responding to an accident tend to be in a hurry because there may be injured workers who need help. Responders should use caution to arrive safely. If the first person to arrive is alone at the scene, the responder should:

• Shout for someone to get help.
• Assess the condition of the victim(s).
• Perform any necessary first aid (if trained).
• Briefly leave to call for emergency assistance (if no one arrives to help).

In most cases, several employees will quickly arrive at the accident scene. A designated person should be in charge, preferably the accident investigator, and that person should delegate authority and set priorities. Some accident scene priorities may include:

• Evaluating the situation,
• Assessing the condition of the victim(s),
• Notifying emergency medical services personnel, and
• Performing basic first aid.

While preserving the evidence at the accident scene is essential, it should never be more important than helping others in need or more important than protecting company property from further damage.

Controlling the accident scene is critical, not only to the success of an accident investigation, but also to the safety of those working at the scene. If the accident scene is disturbed, such as equipment moved or spills cleaned up, gathering facts about what happened will be more difficult. In addition, if bystanders are allowed to enter the accident area, they may interfere with the work of response personnel or disturb evidence needed for the investigation.

Securing the scene

Accident scenes are often disorganized; people may be hurt and equipment might be damaged. In addition, people involved in the accident or who witnessed the accident will likely be upset and may even be in shock. To help control the scene:

• Secure the accident scene,
• Prevent additional accidents from occurring,
• Protect company property from further damage,
• Preserve evidence, and
• Keep upper management informed of the situation.

To secure the accident area, ensure that no one at the scene is in further danger from hazards such as falling debris, sharp objects, or rolling equipment. Continue to secure the area by surveying the accident scene for other hazards such as:

• Fallen electrical wires;
• Fires, chemicals, chemical fumes, or smoke;
• Slippery surfaces; or
• Miscellaneous physical and health hazards.

In order to prevent additional injuries, many of these hazards may need to be immediately corrected (such as the removal of fallen electrical wires), thereby disturbing the accident scene. If this is the case, try to get photos and sketches of the hazards and record some notes about how the hazards may have played a part in the accident.

• Procedures for conducting an accident investigation are extensive, but may not apply in all circumstances due to the variety of accidents and diversity of operations.

These recommendations present a suggested direction; they are not mandatory. Because of the variety of accidents investigated and the diversity of operations, no attempt is made to provide a format for use in all situations. Rather, these guidelines represent an example of an effective investigation procedure that will help to:

• Identify and collect evidence,
• Photograph and sketch the accident scene,
• Write notes,
• Interview observers, and
• Identify contributing factors.

• Identifying and collecting evidence is a multilayered process that can establish the facts of an investigation and the root cause of an accident.

Evidence is anything that helps to establish the facts of an accident investigation to help determine a root cause. Types of evidence can include:

Position of tools and equipment: The position of tools and equipment can provide information about how they were being used (or misused) prior to the accident. Because forklifts and other equipment often look the same, record the serial numbers or other identification numbers to help later identify the specific piece of equipment involved in the accident.

Air quality: If the quality of the air may have contributed to the accident in some way, test the air. Specific things to look for when evaluating air quality include exposure to:

• Carbon dioxide,
• Particulate and dust, and
• Fumes or vapors.

If the air quality contributed to the accident, evaluate the engineering or administrative controls to see if the air quality can be improved, and ensure that proper personal protective equipment (PPE) is used. Determine if employees in the accident area were exposed above the permissible exposure limits (PELs).

Equipment operations logs: Equipment operations logs may provide information about the mechanical integrity of equipment, as well as where, when, and how the equipment has been used. Operations logs, charts, and records may also offer vital information about how the equipment was designed, constructed, installed, and maintained. These records also provide information about equipment malfunction history.

Work environment: Determine if any debris, trash, tools, or equipment contributed to the accident. Additional items to investigate could center around the following types of questions:

• Was there adequate lighting?
• Was visibility limited due to dust or mists?
• Was the noise level excessive?
• Were there any distractions?
• If the accident occurred outdoors, what were the weather conditions at the time of the accident?

Floor or surface conditions: Floor or surface conditions often contribute to accidents. Some questions to ask regarding floor or surface conditions could include:

• Was the work surface dry?
• Was the work surface slippery from oil or grease?
• Does the floor plan allow for the free movement of equipment and pedestrians?
• Were materials stored in the aisleways?
• Does the working area contain slip-resistant flooring material to lessen slip and fall hazards on wet, oily, or greasy surfaces?
• Was the work surface in good condition?

Other contributing factors: Some examples of other contributing factors to consider investigating include:

• Operational errors;
• Violations of rules or procedures;
• Employee morale, attitude, and knowledge;
• Health and safety records; or
• Alcohol and drug abuse.

• Photos and sketches portray the facts in clear fashion and are invaluable in reconstructing an accident scene.

Photos document the facts surrounding an accident and provide the investigator with accurate information about the accident. In order to preserve the facts, instruct workers at the accident scene not to move equipment or other items involved in the accident until photos have been taken of the scene. If equipment must be moved to rescue injured workers, instruct the rescuers to move only what is absolutely necessary.

Take photos of anything that will help reconstruct the entire accident scene. This will usually require a series of photos that first focus on the general area, then progress to specific detailed items. When taking a series of photos, consider the following guidelines:

• Begin with long-range pictures that show as much of the scene as possible. Be sure to take several different angles of the scene.
• Next, take medium-range pictures of the scene. These pictures may begin to focus on pieces of equipment, damaged property, or work areas. Place a ruler, pencil, pen, sheet of paper, or some other object of known size next to items to give perspective of the object or area.
• Finally, take close-range pictures that focus on deficiencies and damage.

Record notes that explain the purpose of each picture and the reasons for taking the picture. These notes will help when creating an accident investigation report. Although photos capture relevant information, they can capture irrelevant information as well. As investigative team members study the photos, it is easy to become distracted with all the details and lose focus on what is truly important.

Other disadvantages to photos include: they may be distorted, and they do not show actual distances. For this reason, sketches of the accident scene should be used in parallel with photos.

Sketching the scene

Sketches are drawings made at an accident scene that provide detailed information about the accident. Sketches are helpful because they can be used later in the final accident investigation analysis and report.

A sketch often provides information that a photo will not. While photos play an important role, the images contain everything the camera sees, including things irrelevant to the investigation. In contrast, sketches contain only pertinent information that helps determine the accident cause.

Sketches should always include information such as an arrow pointing north, angles, distances, locations of people and equipment, and structural or geographical data. Include notes about the sketches that will aid in their use and understanding later. Sketches should only contain information that is directly related to the accident scene.

• Taking good notes is vital to assembling the final accident report.

Accident investigation notes are a record of the facts surrounding an accident that contain information about what people have witnessed. Writing good notes helps develop the final accident investigation report.

Investigation notes should focus on the who, what, when, where, how, and why facts of the accident. Some example questions to ask during an investigation that could be used in the investigation report include:

Who:

• Was involved in the accident?
• Was injured?
• Witnessed the accident?
• Reported the accident?
• Notified emergency medical services personnel?

What:

• Happened?
• Company property was damaged?
• Evidence was found?
• Was done to secure the accident scene?
• Was done to prevent a recurrence of the accident?
• Level of medical care did the victims require?
• Was being done at the time of the accident?
• Tools were being used?
• Was the employee told to do?
• Machine was involved?
• Operation was being performed?
• Instructions had been given?
• Precautions were necessary?
• Protective equipment should have been used?
• Did others do to contribute to the accident?
• Did witnesses see?
• Safety rules were violated?
• Safety rules were lacking?
• New safety rules or procedures are needed?

When:

• Did the accident happen?
• Was it discovered?
• Was the accident reported?
• Did the employee begin the task?
• Were hazards pointed out to the employee?
• Did the supervisor last check the employee’s progress?

Where:

• Did the accident happen?
• Was the employee’s supervisor when the accident occurred?
• Were coworkers when the accident occurred?
• Were witnesses when the accident occurred?
• Does this condition exist elsewhere in the facility?
• Is the evidence of the investigation going to be kept?

How:

• Did the accident happen?
• Was the accident discovered?
• Were employees injured?
• Was equipment damaged?
• Could the accident have been avoided?
• Could the supervisor have prevented the accident from happening?
• Could coworkers avoid similar accidents?

Why:

• Did the accident happen?
• Were employees injured?
• Did the employee behave that way?
• Wasn’t protective equipment used?
• Weren’t specific instructions given to the employee?
• Was the employee in that specific position or place?
• Was the employee using that machine or those tools?
• Didn’t the employee check with the supervisor?
• Wasn’t the supervisor there at the time?

• Consistency in conducting interviews and keeping records can assist with ongoing analysis of accident types and trends.
• To conduct a successful accident interview, develop effective interviewing techniques.

Conducting a detailed interview is probably not necessary for every accident. However, a consistent approach will enhance any ongoing analysis of accident types and trends.

When interviewing the victim(s) and observers, the goal is to get the facts, not to assign blame or point out how expensive or damaging the situation may be.

To conduct productive interviews, consider the following points:

• Conduct interviews as soon as possible after the accident, ideally at the accident scene. By interviewing as soon as possible, the employees’ recall will be sharper. Not only is the incident more vivid in their minds, but there is less chance for family or friends to influence the way the mishap is reported.
• Verify the employee’s physical and mental condition, especially if interviewing at the accident scene.
• Express concern for the employee’s well-being. Doing so helps to avoid defensiveness.
• Most companies rely on one person to conduct initial interviews. However, knowledge of a given employee and that employee’s personality could motivate a desire to have a second person present for some people who may get aggressive.

Before conducting an interview, an interviewer should verify compliance with all company policies and/or union contracts. Also, privacy is essential when interviewing. Conduct interviews in a nearby office or vehicle.

List of interviewing do’s

Successful interviewers stress these techniques:

• Conduct the interview at the scene of the accident, if possible.
• Explain that only the facts are needed. Filter out any defensiveness, name calling, or blaming.
• Explain that the goal of the investigation is to prevent future accidents. That puts the interview on the level of learning experience instead of inquisition.
• When interviewing witnesses, remind the employee that the investigation is to determine causes to prevent future injuries.
• Ask open-ended questions. Questions that can be answered yes or no are not open-ended, and the question should be rephrased. An example of a yes/no question would be: “Was the Number 5 press in good condition at the time of the accident?” An example of an open-ended question would be: “How would you describe the condition of the Number 5 press at the time of the accident?”
• Ask the employee to describe exactly what happened. Do not interrupt or ask for more details at this time.
• Repeat the employee’s version of the event back and allow any corrections or additions.
• After the employee has given a description of the event, ask appropriate questions that focus on causes. Avoid using words or body language that suggest fault or blame.
• When finished, remind the employee the investigation was to determine the cause and possible corrective action that can eliminate the cause(s) of the accident.
• End the interview on a positive note by thanking the person for helping with the interview process.

List of interviewing don’ts

When conducting the interview:

• Don’t make judgment calls about the accident and who may be responsible.
• Don’t respond in kind to an employee’s defensiveness, finger pointing, or emotional outbursts.
• Don’t pressure the person being interviewed.
• Don’t use a tone of voice that is demanding, sarcastic, or accusatory.
• Don’t interrupt the person being interviewed.
• Don’t ask why or opinion questions such as, “Why do you think that?”

• Investigators must understand the difference between a surface cause and a root cause before searching for root causes of an accident.
• Reviewing the evidence and examining reasons for employee actions are instrumental in identifying root causes.

Identifying a root cause is ultimately what the accident investigation is all about. The investigation will likely discover several causes, not just one. Determining root causes involves:

• Looking at the overall effect of the accident on people, property, products, and processes;
• Examining all potential causes; and
• Determining the reasons for employee actions that contributed to the accident.

It’s important to understand the difference between a symptom or surface cause, and a root cause.

A symptom is a contributing factor, while a root cause is the actual cause of the accident. For example, if a hammer falls from a scaffold and strikes a worker, the symptom is the falling hammer. The root cause might be a missing toeboard on the scaffold, where the hammer was accidentally pushed off the edge. Telling a worker to be more careful is unlikely to prevent other items from falling in the future.

While it is important to evaluate surface actions and conditions, doing so often leads to an emphasis on the individuals, which then tends to focus blame.

After identifying the root cause or causes, use that information to develop the corrective and preventive actions that will help prevent future accidents.

Reviewing the evidence

Examining the evidence collected along with the notes, photos, and sketches should help identify a root cause. If clarification is needed, consulting further with the accident witnesses and victims may be an option. Understand that some witnesses and victims may be able to provide a detailed account of the accident, while others may not be able to recall much information. Simply try to get them to remember as much information as they can.

Finally, understand that some witnesses or victims may not wish to discuss the accident if they were traumatized by the event. Be sure to ask witnesses or victims if they are able to further discuss the accident.

Examining reasons for employee actions

When looking for root causes, determine why an employee acted a particular way prior to the accident, and look at the specific conditions of the task performed just prior to the accident. Some questions to consider include the following:

• Was there something unusual or different about the job or task on the day of the accident?
• Was there a production push at the time the accident occurred?
• Was there a communications breakdown between employees or supervisors?
• Was the employee properly trained?
• Was personal protective equipment available?
• Was the employee in a hurry? Fatigued? Taking shortcuts to complete the task?
• Were procedures inaccurate?
• Was the accident due to any external factors?
• Were tools being incorrectly used?

Remember, the goal should be to identify the failures at a deep level in order to prevent not only a recurrence of the accident, but all potential accidents stemming from the same root cause.

• Asking the right questions can simplify identification of root causes of an accident.

Source: Occupational Safety and Health Administration (OSHA) incident investigation guide, 2015

A thorough approach to identifying root causes involves questioning employees and supervisors about actions and conditions surrounding the accident. The following questions provide ideas to help an interviewer drill down to the root causes:

1. Did a written or well-established procedure exist for employees to follow?
2. Did job procedures or standards properly identify potential hazards of job performance?
3. Were there any hazardous environmental conditions that may have contributed to the incident?
4. Were the hazardous environmental conditions recognized by employees or supervisors?
5. Were any actions taken by employees, supervisors, or both to eliminate or control environmental hazards?
6. Were employees trained to deal with any hazardous environmental conditions that could arise?
7. Was sufficient space provided to accomplish the job task?
8. Was lighting adequate to properly perform all assigned tasks?
9. Were employees familiar with job procedures?
10. Was there any deviation from established job procedures?
11. Were the proper equipment and tools available and being used for the job?
12. Did any mental or physical conditions prevent the employee(s) from properly performing their jobs?
13. Were there any tasks considered more demanding or difficult than usual (e.g., strenuous activities, excessive concentration required, etc.)?
14. Was there anything different or unusual from normal operations (e.g., different parts, new or different chemicals used, recent adjustments/maintenance/cleaning on equipment)?
15. Was the proper personal protective equipment (PPE) specified for the job or task?
16. Were employees trained in the proper use of any PPE?
17. Did employees use the prescribed PPE?
18. Was PPE damaged or not properly functioning?
19. Were employees trained and familiar with proper emergency procedures, including the use of any special emergency equipment, and was it available?
20. Was there any indication of misuse or abuse of equipment and/or materials at the incident site?
21. Is there any history of equipment failure, were all safety alerts and safeguards operational, and was the equipment functioning properly?
22. If applicable, are all employee certification and training records current and up‐to‐date?
23. Was there any shortage of personnel on the day of the incident?
24. Did supervisors detect, anticipate, or report an unsafe or hazardous condition?
25. Did supervisors recognize deviations from the normal job procedure?
26. Did supervisors and employees participate in job review sessions, especially for those jobs performed infrequently?
27. Were supervisors made aware of their responsibilities for the safety of their work areas and employees?
28. Were supervisors properly trained in the principles of incident prevention?
29. Was there any history of personnel problems or conflicts with or between supervisors and employees, or between employees themselves?
30. Did supervisors conduct regular safety meetings with their employees?
31. Were the topics discussed and actions taken during safety meetings recorded in the minutes?
32. Were the proper resources (i.e., equipment, tools, materials, etc.) required to perform the job or task readily available and in proper condition?
33. Did supervisors ensure employees were trained and proficient before assigning them to their jobs?

One option for uncovering a root cause is to repeatedly ask “why” questions until the process uncovers a deeper reason for a failure.

The Five Whys is one root cause analysis methodology. It is used to explore the cause/effect relationships underlying a particular problem. Ultimately, the goal of applying the Five Whys method is to determine a root cause of a defect or problem.

The following example of a car not starting demonstrates the basic process:

1. Why? - The battery is dead.
2. Why? - The alternator is not functioning.
3. Why? - The alternator belt has broken.
4. Why? - The alternator belt was beyond its useful service life and was never replaced.
5. Why? - I have not been maintaining my car according to the recommended service schedule. (root cause)

Note that the questioning could be taken to a sixth, seventh, or even greater level since the “five” in Five Whys is not set in stone. However, five iterations is generally sufficient to identify a root cause. The real key is to encourage the troubleshooter to avoid assumptions and logic traps and instead to trace the chain of causality in direct increments from the effect through any layers of abstraction to a root cause that still has some connection to the original problem.

• Recommendations for corrective and preventive actions are necessary to minimize or eliminate the likelihood of another accident happening.
• Findings in a final report concerning an accident investigation must be communicated to upper management, with the goal of preventing future accidents.

After determining the root cause of an accident, corrective and preventive actions must be implemented that will eliminate, or at least reduce, the chances of another accident occurring.

Developing an effective set of corrective and preventive actions starts with an evaluation of the identified root cause(s). Usually, recommendations for corrective actions follow in a rather straightforward manner.

Evaluate each root cause to determine how it can be prevented in the future. With the help of other supervisors, managers, and employees, discuss ways to remove the root cause from the system. Ensure that root causes (not merely symptoms or surface causes) are evaluated and discussed.

To aid in a discussion of root causes, refer to the list of why or why-not questions that probably led to the root cause. Develop a list of potential employee actions that may have contributed to the accident. By thoroughly evaluating this information, an investigator will be one step closer to reducing or eliminating root causes of accidents.

Depending on the situation and the type of root cause, there may be several potential options for reducing or eliminating root causes. Some examples may include:

• Seeking input from employees about how to create a safer working atmosphere,
• Conducting hazard assessment classes,
• Establishing procedures to correct or control all current and potential hazards in a timely manner,
• Establishing safety committees,
• Providing for facility and equipment maintenance to reduce equipment malfunctions and breakdowns, and
• Conducting frequent job refresher training classes.

Often, a thorough accident investigation will result in recommendations for improving a process or reducing hazards. Use the investigation as an opportunity to look for ways to improve the efficiency of a process, the working habits of employees, and the overall safety of the working area.

Some example recommendations may include: increasing lighting in a work area, improving machine guarding, establishing new procedures for housekeeping, or improving communication between management and employees.

Communicating the findings

Because upper management is ultimately responsible for the health and safety of the workforce, the findings of the accident investigation must be reported to them. In order to effectively communicate the investigation findings, provide the following information in the final report:

• A description of the accident (including the date, time, and location);
• The facts determined during the investigation (including chronology as appropriate);
• A list of the suspected root causes; and
• The recommendations for corrective and preventive action (including timing and responsibility for completion).

Through proper documentation of the accident investigation findings, and by reviewing the results of the investigation with appropriate personnel, recurrence of accidents may be prevented.