Accident Investigation
“If you think safety is expensive, try an accident”
Multiple Accident Causes
There are more than one cause of an accident, not only in sequence but occurring at the same time.
Methods of calculating loss rates from raw data:
Accident or Incident severity rate:
Number of days lost compared with number of man hours worked
Ill-health prevalence rate:
Number of ill health conditions compared with number of people (Number of people in the population exposed)
The data collection by
- The organization
- An enforcing authority
- Medical provision organizations
- Government statistics organizations
- Insurance organization
Standard Outline (implied) legal requirements and HSE guidance, Investigating Accidents and Incidents
Outline purposes to discover underlying causes, root-cause analysis, prevention of recurrence, legal liability, data gathering and identification of trends description of investigation procedures and methodologies to include incident report forms, gathering of relevant information, interviewing witnesses, analysis of information and the involvement of managers, supervisors, employees, safety representatives and others in the investigation process outline use of failure tracing methods - such as fault tree analysis and event tree analysis (ETA) - as investigative tools.
- Step one: Gathering the information
- Step two: Analysing the information
- Step three: Identifying risk control measures
- Step four: The action plan and its implementation
Adverse event includes:
- Accident: an event that results in injury or ill health;
- Incident:
– Near miss: an event that, while not causing harm, has the potential to cause injury or ill health. (in this guidance, the term near miss will be taken to include dangerous occurrences);
– Undesired circumstance: a set of conditions or circumstances that have the potential to cause injury or ill health.
Hazard: the potential to cause harm, including ill health and injury; damage to property, plant, products or the environment, production losses or increased liabilities.
Immediate cause: the most obvious reason why an adverse event happens, eg the guard is missing; the employee slips etc. There may be several immediate causes identified in any one adverse event.
Consequence:
Fatal: work-related death;
Major injury/ill health: including fractures (other than fingers or toes), amputations, loss of sight, a burn or penetrating injury to the eye, any injury or acute illness resulting in unconsciousness, requiring resuscitation or requiring admittance to hospital for more than 24 hours; serious injury/ill health: where the person affected is unfit to carry out his or her normal work for more than three consecutive days;
Minor injury: all other injuries, where the injured person is unfit for his or her normal work for less than three days; damage only: damage to property, equipment, the environment or production losses. (referring to the potential to cause harm to people.)
Terms with Likelihood that an adverse event will happen again:
- Certain: it will happen again and soon;
- Likely: it will reoccur, but not as an everyday event;
- Possible: it may occur from time to time;
- Unlikely: it is not expected to happen again in the foreseeable future;
- Rare: so unlikely that it is not expected to happen again.
Risk: The level of risk is determined from a combination of the likelihood of a specific undesirable event occurring and the severity of the consequences (ie how often is it likely to happen, how many people could be affected and how bad would the likely injuries or ill health effects be?)
Risk control measures: are the workplace precautions put in place to reduce the risk to a tolerable level
Root cause: an initiating event or failing from which all other causes or failings spring. Root causes are generally management, planning or organisational failings.
Underlying cause: the less obvious ‘system’ or ’organisational’ reason for an adverse event happening, eg pre-start-up machinery checks are not carried out by supervisors; the hazard has not been adequately considered via a suitable and sufficient risk assessment; production pressures are too great etc.
Event and Cause
Cause of Adverse Events
þ Immediate causes: the agent of injury or ill health (the blade, the substance, the dust etc);
þ Underlying causes: unsafe acts and unsafe conditions (the guard removed, the ventilation switched off etc);
þ Root causes: the failure from which all other failings grow, often remote in time and space from the adverse event (eg failure to identify training needs and assess competence, low priority given to risk assessment etc).
To prevent adverse events, you need to provide effective risk control measures which address the immediate, underlying and root causes.
Legal reasons for investigating
þ To ensure you are operating your organisation within the law.
þ The Factory Act, requires employers to plan, organise, control, monitor and review their health and safety arrangements. Health and safety investigations form an essential part of this process.
þ The fear of litigation may make you think it is better not to investigate, but you can’t make things better if you don’t know what went wrong!
þ The fact that you thoroughly investigated an accident and took remedial action to prevent further accidents would demonstrate to a court that your company has a positive attitude to health and safety.
þ Investigation findings will also provide essential information for your insurers in the event of a claim.
Information and insights gained from an investigation
þ An understanding of how and why things went wrong.
þ An understanding of the ways people can be exposed to substances or conditions that may affect their health.
þ A true snapshot of what really happens and how work is really done. (Workers may find short cuts to make their work easier or quicker and may ignore rules. You need to be aware of this.)
þ Identifying deficiencies in your risk control management, which will enable you to improve your management of risk in the future and to learn lessons which will be applicable to other parts of your organisation.
Benefits arising from an investigation
þ The prevention of further similar adverse events. If there is a serious accident, the regulatory authorities will take a firm line if you have ignored previous warnings.
þ The prevention of business losses due to disruption, stoppage, lost orders and the costs of criminal and civil legal actions.
þ An improvement in employee morale and attitude towards health and safety. Employees will be more cooperative in implementing new safety precautions if they were involved in the decision and they can see that problems are dealt with.
Investigation Report Forms vary in design, layout and content.
Level 1 Report: Initial investigation report by first line managers. Mainly identifying immediate causes of accidents.
Level 2 Report: In-depth investigation by other managers and health and safety professionals. More analysis and investigation of root / underlying causes.
Level 3 Report: Reports prepared by the investigation teams. The common structure of the report tends to determine
What happened (The loss), How it happened (The event), Why it happened (The causes) and Recommendations (Corrective and preventive actions).
Understanding this line of investigation is not value to the organization but value addition. Post investigation or any incident report most of the organization or individuals are not able to follow or arrange for the correct provision needed for post incident it becomes cost finding objective or consequence cost. For a systematic investigation or any incident reporting objective is to first educate people on information gathering, quantifying not qualitatively outlining best practices.
Through practical approach incident or accident investigation is required to be on a measurable scale. Working on industrial safety and occupational health doable we often come across many facts, systems and terms. To scale the implementation process of upgradation of any industrial system one should focus on few points us under.
1. Provide an action plan with SMART objectives (Specific, Measurable, Agreed, Realistic and Timescaled);
2. Ensure that the action plan deals effectively not only with the immediate and underlying causes but also the root causes;
3. Include lessons that may be applied to prevent other adverse events, eg. assessments of skill and training in competencies may be needed for other areas of the organisation;
4. Communicate the results of the investigation and the action plan to everyone who needs to know;
5. Include arrangements to ensure the action plan is implemented and progress monitored.
