Wednesday, 12 October 2016

HUMAN ERROR - FAILURE


Human Error is commonly defined as “a failure of a planned action to achieve a desired outcome”. Error-inducing factors exist at individual, job, and organisational levels, and when poorly managed can increase the likelihood of an error occurring in the workplace. When errors occur in hazardous environments, there is a greater potential for things to go wrong. By understanding human error, responsible parties can plan for likely error scenarios, and implement barriers to prevent or mitigate the occurrence of potential errors.
Errors result from a variety of influences, but the underlying mental processes that lead to error are consistent, allowing for the development of a human error typology. An understanding of the different error types is critical for the development of effective error prevention and mitigation tools and strategies.  A variety of these tools and strategies must be implemented to target the full range of error types if they are to be effective.
Errors can occur in both the planning and execution stages of a task. Plans can be adequate or inadequate, and actions (behaviour) can be intentional or unintentional. If a plan is adequate, and the intentional action follows that plan, then the desired outcome will be achieved. If a plan is adequate, but an unintentional action does not follow the plan, then the desired outcome will not be achieved. Similarly, if a plan is inadequate, and an intentional action follows the plan, the desired outcome will again not be achieved. These error points are demonstrated in the figure below and explained in the example that follows.

Human error – failures in planning and execution


Human error typology

Failures of action, or unintentional actions, are classified as skill-based errors. This error type is categorised into slips of action and lapses of memory. Failures in planning are referred to as mistakes, which are categorised as rule-based mistakes and knowledge-based mistakes.




Skill-based Errors

Skill-based errors tend to occur during highly routine activities, when attention is diverted from a task, either by thoughts or external factors. Generally when these errors occur, the individual has the right knowledge, skills, and experience to do the task properly. The task has probably been performed correctly many times before. Even the most skilled and experienced people are susceptible to this type of error. As tasks become more routine and less novel, they can be performed with less conscious attention – the more familiar a task, the easier it is for the mind to wander. This means that highly experienced people may be more likely to encounter this type of error than those with less experience. This also means that re-training and disciplinary action are not appropriate responses to this type of error.
A memory lapse occurs after the formation of the plan and before execution, while the plan is stored in the brain. This type of error refers to instances of forgetting to do something, losing place in a sequence, or even forgetting the overall plan. 
A slip of action is an unintentional action. This type of error occurs at the point of task execution, and includes actions performed on autopilot, skipping or reordering a step in a procedure, performing the right action on the wrong object, or performing the wrong action on the right object. Typical examples include:
·         missing a step in an isolation sequence
·         pressing the wrong button or pulling the wrong lever
·         loosening a valve when intending to tighten it
·         transposing digits when copying numbers

Mistakes

Mistakes are failures of planning, where a plan is expected to achieve the desired outcome, however due to inexperience or poor information the plan is not appropriate. People with less knowledge and experience may be more likely to experience mistakes. However, as mistakes are not committed ‘on purpose’, disciplinary action is an inappropriate response to these types of error.  Knowledge-based mistakes result from ‘trial and error’. Insufficient knowledge about how to perform a task results in the development of a solution that is incorrectly expected to work.


Rule-based mistakes refer to situations where the use or disregard of a particular rule or set of rules results in an undesired outcome.
There are three types of rule-based mistakes:
·         incorrect application of a good rule
·         correct application of a bad rule
·         failure to apply a good rule.
 Some rules that are appropriate for use in one situation will be inappropriate in another. Incorrect application of a good rule occurs when a rule has worked well on previous occasions, so it is applied to a similar situation with the incorrect expectation that it will work. Sometimes rules are inappropriate or incorrect, and adherence leads to negative outcomes.

Violations

Failure to apply a good rule is also known as a violation. Violations are classified as human error when the intentional action does not achieve the desired outcome. Violations tend to be well-intentioned, targeting desired outcomes such as task completion and simplification. Where violations involve acts of sabotage designed to cause damage, the planned action (violation) has achieved the desired outcome (damage). This type of behaviour does not constitute human error and, following investigation, should be managed through the application of appropriate disciplinary measures. There are three main types of violations pertaining to human error: routine, situational, and exceptional.

A routine violation is one which is commonplace and committed by most members of the workplace. For example, in a particular office building it is against the rules for personnel to use the fire escape stairwell to move between floors, but it is common practice for people to do so anyway.

A situational violation occurs, as its name suggests, in response to situational factors, including excessive time pressure, workplace design, and inadequate or inappropriate equipment. When confronted with an unexpected or inappropriate situation, personnel may believe that the normal rule is no longer safe, or that it will not achieve the desired outcome, and so they decide to violate that rule. Situational violations generally occur as a once-off, unless the situation triggering the violation is not corrected, in which case the violation may become routine over time.

An exceptional violation is a fairly rare occurrence and happens in abnormal and emergency situations. This type of violation transpires when something is going wrong and personnel believe that the rules no longer apply, or that applying a rule will not correct the problem. Personnel choose to violate the rule believing that they will achieve the desired outcome.

Preventing violations requires an understanding of how motivation drives behaviour. Planned behaviour (intentional action) is driven by an individual’s attitude towards that behaviour. Further, individual decision-making is primarily influenced by the consequences the individual expects to receive as a result of their behaviour, which can influence their attitude towards that behaviour.


In most organisations, consequences associated with risk management behaviours compete against those associated with productivity behaviours.  While ‘Safe Production’ is a popular phrase, risk management activities necessarily increase the amount of time required to complete a task. Productivity outcomes are generally more predictable and definitive than those associated with risk management (i.e. definitely achieving a target versus potentially avoiding an incident).  So the perceived value of productivity behaviour may be greater than that of risk management behaviour.

Note: Violations are classified as human error only when they fail to achieve the desired outcome. Where a violation does achieve the desired outcome, and does not cause any other undesired outcomes, this is not human error. These types of violations may include violation of a bad rule, such as a procedure that, if followed correctly, would trip the plant. In such cases, a review of the rules and procedures is advisable.

Post by 
Department of Ocuupational Safety & Health Training Institute
www.doshti.com


HUMAN ERROR - FAILURE


Human Error is commonly defined as “a failure of a planned action to achieve a desired outcome”. Error-inducing factors exist at individual, job, and organisational levels, and when poorly managed can increase the likelihood of an error occurring in the workplace. When errors occur in hazardous environments, there is a greater potential for things to go wrong. By understanding human error, responsible parties can plan for likely error scenarios, and implement barriers to prevent or mitigate the occurrence of potential errors.
Errors result from a variety of influences, but the underlying mental processes that lead to error are consistent, allowing for the development of a human error typology. An understanding of the different error types is critical for the development of effective error prevention and mitigation tools and strategies.  A variety of these tools and strategies must be implemented to target the full range of error types if they are to be effective.
Errors can occur in both the planning and execution stages of a task. Plans can be adequate or inadequate, and actions (behaviour) can be intentional or unintentional. If a plan is adequate, and the intentional action follows that plan, then the desired outcome will be achieved. If a plan is adequate, but an unintentional action does not follow the plan, then the desired outcome will not be achieved. Similarly, if a plan is inadequate, and an intentional action follows the plan, the desired outcome will again not be achieved. These error points are demonstrated in the figure below and explained in the example that follows.

Human error – failures in planning and execution


Human error typology

Failures of action, or unintentional actions, are classified as skill-based errors. This error type is categorised into slips of action and lapses of memory. Failures in planning are referred to as mistakes, which are categorised as rule-based mistakes and knowledge-based mistakes.




Skill-based Errors

Skill-based errors tend to occur during highly routine activities, when attention is diverted from a task, either by thoughts or external factors. Generally when these errors occur, the individual has the right knowledge, skills, and experience to do the task properly. The task has probably been performed correctly many times before. Even the most skilled and experienced people are susceptible to this type of error. As tasks become more routine and less novel, they can be performed with less conscious attention – the more familiar a task, the easier it is for the mind to wander. This means that highly experienced people may be more likely to encounter this type of error than those with less experience. This also means that re-training and disciplinary action are not appropriate responses to this type of error.
A memory lapse occurs after the formation of the plan and before execution, while the plan is stored in the brain. This type of error refers to instances of forgetting to do something, losing place in a sequence, or even forgetting the overall plan. 
A slip of action is an unintentional action. This type of error occurs at the point of task execution, and includes actions performed on autopilot, skipping or reordering a step in a procedure, performing the right action on the wrong object, or performing the wrong action on the right object. Typical examples include:
·         missing a step in an isolation sequence
·         pressing the wrong button or pulling the wrong lever
·         loosening a valve when intending to tighten it
·         transposing digits when copying numbers

Mistakes

Mistakes are failures of planning, where a plan is expected to achieve the desired outcome, however due to inexperience or poor information the plan is not appropriate. People with less knowledge and experience may be more likely to experience mistakes. However, as mistakes are not committed ‘on purpose’, disciplinary action is an inappropriate response to these types of error.  Knowledge-based mistakes result from ‘trial and error’. Insufficient knowledge about how to perform a task results in the development of a solution that is incorrectly expected to work.


Rule-based mistakes refer to situations where the use or disregard of a particular rule or set of rules results in an undesired outcome.
There are three types of rule-based mistakes:
·         incorrect application of a good rule
·         correct application of a bad rule
·         failure to apply a good rule.
 Some rules that are appropriate for use in one situation will be inappropriate in another. Incorrect application of a good rule occurs when a rule has worked well on previous occasions, so it is applied to a similar situation with the incorrect expectation that it will work. Sometimes rules are inappropriate or incorrect, and adherence leads to negative outcomes.

Violations

Failure to apply a good rule is also known as a violation. Violations are classified as human error when the intentional action does not achieve the desired outcome. Violations tend to be well-intentioned, targeting desired outcomes such as task completion and simplification. Where violations involve acts of sabotage designed to cause damage, the planned action (violation) has achieved the desired outcome (damage). This type of behaviour does not constitute human error and, following investigation, should be managed through the application of appropriate disciplinary measures. There are three main types of violations pertaining to human error: routine, situational, and exceptional.

A routine violation is one which is commonplace and committed by most members of the workplace. For example, in a particular office building it is against the rules for personnel to use the fire escape stairwell to move between floors, but it is common practice for people to do so anyway.

A situational violation occurs, as its name suggests, in response to situational factors, including excessive time pressure, workplace design, and inadequate or inappropriate equipment. When confronted with an unexpected or inappropriate situation, personnel may believe that the normal rule is no longer safe, or that it will not achieve the desired outcome, and so they decide to violate that rule. Situational violations generally occur as a once-off, unless the situation triggering the violation is not corrected, in which case the violation may become routine over time.

An exceptional violation is a fairly rare occurrence and happens in abnormal and emergency situations. This type of violation transpires when something is going wrong and personnel believe that the rules no longer apply, or that applying a rule will not correct the problem. Personnel choose to violate the rule believing that they will achieve the desired outcome.

Preventing violations requires an understanding of how motivation drives behaviour. Planned behaviour (intentional action) is driven by an individual’s attitude towards that behaviour. Further, individual decision-making is primarily influenced by the consequences the individual expects to receive as a result of their behaviour, which can influence their attitude towards that behaviour.


In most organisations, consequences associated with risk management behaviours compete against those associated with productivity behaviours.  While ‘Safe Production’ is a popular phrase, risk management activities necessarily increase the amount of time required to complete a task. Productivity outcomes are generally more predictable and definitive than those associated with risk management (i.e. definitely achieving a target versus potentially avoiding an incident).  So the perceived value of productivity behaviour may be greater than that of risk management behaviour.

Note: Violations are classified as human error only when they fail to achieve the desired outcome. Where a violation does achieve the desired outcome, and does not cause any other undesired outcomes, this is not human error. These types of violations may include violation of a bad rule, such as a procedure that, if followed correctly, would trip the plant. In such cases, a review of the rules and procedures is advisable.

Post by 
Department of Ocuupational Safety & Health Training Institute
www.doshti.com


Monday, 15 February 2016

Struck-By Hazard



What Is A Struck-By Hazard?

A struck-by hazard is anything at your worksite that could produce injuries by forcible contact or impact between the injured person and an object or piece of equipment. Struck-by hazards fall into four categories:

·         Flying object
·         Falling object
·         Swinging object
·         Rolling object



What Are The Common Types Of Struck-by Hazards?

The following categories of struck-by hazards include examples of common types of hazards.

Struck-By Flying Object

 “A flying object hazard exists when something has been thrown, hurled, or is being propelled across space”.

Examples of struck-by flying object hazards:
·         A piece of material separates from a tool, machine, or other equipment and strikes a worker.
·         An object is ejected under power by a tool or equipment usually designed for that purpose, such as a nail from a nail gun.
·         Compressed air used to power tools or clean surfaces causes flying object hazards.

  
Struck-By Falling Object

Struck-by falling object hazards are those that involve objects falling from an elevation to a lower level. Injuries from these hazards include instances where the injured person is crushed, pinned, or caught under a falling object.

Examples of struck-by falling object hazards:
·         A worker is struck by a load, or parts of a load, that falls from a vehicle or other equipment
·         A crane boom, or other piece of equipment, breaks, collapses, and strikes a worker.
·         A section from a structure that is being cut apart falls and strikes a person



Struck-By Swinging Object

 Struck-by swinging object hazards usually exist when materials are being mechanically lifted. The load may swing, twist, or turn, especially when there are windy conditions.

Examples of struck-by swinging object hazards:
·         A worker is hit while working within the swing radius of a crane
·         While lifting a load, the boom of a crane collapses and strikes a worker
·         A gust of wind unexpectedly pushes a prefabricated wall while it was being lifted into position, causing it to strike a worker

Struck-By Rolling Object
Struck-by rolling object hazards exist when a worker is exposed to objects that are rolling, moving, or sliding on the same level at which the worker is located. This hazard includes instances involving moving vehicles or equipment.

Examples of struck-by rolling object hazards:
·         Worker is struck by an unmanned rail car
·         A road crew worker is struck by a vehicle
·         A mobile crane runs over a ground crew member



How Can I Protect Myself From Struck-By Hazards?

You can protect yourself from struck-by hazards by following safe practices, including those related to:
·         Heavy equipment [cranes, excavators]
·         Motor vehicles [trucks, cars]
·         General safe work practices
·         Personal Protective Equipment [PPE]

Heavy Equipment Safe practices for preventing struck-by injuries from heavy equipment:

·         Stay away from heavy equipment when it is operating – in fact, be alert to the location of all heavy equipment whether in use or not
·         Stay clear of lifted loads and never work under a suspended load
·         Beware of unbalanced loads
·         Workers should confirm and receive acknowledgement from the heavy equipment operator that they are visible
·         Be aware of the swing radius of cranes and backhoes and do not enter that zone
·         Drive equipment [or vehicles] on grades or roadways that are safely constructed and maintained
·         Make sure that all workers and other personnel are in the clear before using dumping or lifting devices
·         Lower or block bulldozer and scraper blades, end-loader buckets, dump bodies, etc., when not in use, and leave all controls in neutral position
·         Haulage vehicles that are loaded by cranes, power shovels, loaders, etc., must have a cab shield or canopy that protects the driver from falling materials
·         Do not exceed a vehicle’s rated load or lift capacity
·         Do not carry personnel unless there is a safe place to ride.

Motor Vehicles Safe practices for preventing struck-by injuries from vehicles at construction sites:
·         Wear seat belts when provided
·         Check vehicles before each shift to assure that all parts and accessories are in safe operating condition
·         Do not drive a vehicle in reverse gear with an obstructed rear view, unless it has an audible reverse alarm, or another worker signals that it is safe
·         Set parking brakes when vehicles and equipment are parked, and chock the wheels if they are on an incline
·         All vehicles must have adequate braking systems and other safety devices
·         Use traffic signs, barricades, or flaggers when construction takes place near public roadways
·         Workers must be highly visible in all levels of light. Warning clothing, such as red or orange vests, are required; and if worn for night work, must be of reflective material

When working on or near any construction zone:

·         Wear high-visibility reflective clothing
·         Do not put yourself at risk of being struck by a vehicle and do not get caught in a situation where there’s no escape route
·         Do not direct traffic unless you are the flagger
·         Check that necessary warning signs are posted
·         Never cross the path of a backing vehicle
·         Follow “Exit” and “Entry” worksite traffic plan

General Safe Working Practices

WSH provides the following general safe working practices for preventing struck-by injuries:

When working with compressed air: Reduce air pressure to 30 psi if used for cleaning, and use only with appropriate guarding and proper protective equipment; and, never clean clothing with compressed air

When working with hand tools: Do not use tools with loose, cracked, or splintered handles; and, do not use impact tools with mushroomed heads

When working with machines, such as jack hammers, pavement saws: Be sure to be trained on safe operation of machinery; inspect machinery; ensure all guards are in place and in working order; and protect feet, eyes, ears, and hands - wear hearing protection.

When performing overhead work: Secure all tools and materials; use toeboards, screens, guardrails, and debris nets; barricade the area and post signs; and, be sure materials stored in buildings under construction are placed farther than 6 feet of hoist way/floor openings, and more than 10 feet from an exterior wall

When working with powder-actuated tools: Be sure to be trained and licensed to operate these tools if required.

When working with power tools, such as saws, drills, or grinders: Be sure to be trained on how to safely use the power tool; inspect tool(s) before each use; wear safety goggles; operate according to manufacturer’s instructions; and, ensure that all required guards are in place

When pushing or pulling objects that may become airborne: Stack and secure materials to prevent sliding, falling, or collapse; keep work areas clear; and, secure material against wind gusts.

Personal Protective Equipment (PPE)

WSH recommendations for PPE for workers exposed to struck-by hazards:

Eye and face protection:
·         Use based on anticipated hazards
·         Safety glasses or goggles should be worn any time work operations present an eye hazard – for example, during welding, cutting, grinding, nailing (or when working with concrete and/or harmful chemicals or when exposed to flying particles)

Head protection:
·         Wear hard hats where there is a potential for objects falling from above, bumps to the head from fixed objects
·         Hard hats – routinely inspect for dents, cracks, or deterioration; replace after a heavy blow; maintain in good condition

What is my employer required to do to protect workers from struck-by hazards?

Safety Regulation requires employers to protect workers from struck by hazards. Employers are required to:
·         Meet all heavy equipment, motor vehicle, and general requirements included in Safety  standards
·         Provide proper PPE
·         Provide required training

·         Ensure qualification of operator, rigger, signal person, and competent person

Post by Department of Safety & Health Training Institute
www.doshti.com