Chapter 20. Accident Causation and Investigation Flashcards
Reasons to conduct an accident investigation
- prevent future occurrences of same incident
- accidents and illnesses limit efficiency and productivity
- accidents are detrimental to employee morale
- federal and state regulations
- insurance premiums lower with fewer accidents
Domino Theory of Accident Causation
First scientific approach to accident prevention
* accident is one event in a chain reaction / sequence
1. social environment
2. human error /fault of person
3. unsafe act or condition
4. accident
5. Injury
Henrich’s Axioms of Industrial Safety
- injuries result from completed set of factors
- accidents only occur as result of unsafe act by person or a physical or mechanical hazard
- most accidents are from unsafe behavior
- unsafe acts do not always result in an accident/injury
- Reasons for unsafe actions will aid in corrective actions
- Severity is fortuitous and cause largely preventable
- accident prevention analogous with best practices
- management should be responsible for safety
- supervisor is key person in accident prevention
- any accident results in direct and indirect costs
Heinrich’s corrective sequence actions
3E
1. Engineering
2. Education
3. Enforcement
Human Factors Theory of Accident Causation
Accidents entirely result of human error
1. Overload
2. Inappropriate worker response
3. Inappropriate activities
Accident/ Incident Theory of Accident Causation
Peterson’s Model
Based on Human Factors Theory
Adds system failure
Adds decision to err (subconcious or concious - Superman syndrome)
Management role is multilayered- training, enforcement, policy setting, compliance
Epidemiological Theory of Accident Causation
causal relationship between environmental factors and disease
predispositional characteristics and situational characteristics
Systems Theory of Accident Causation
relationship between man, machine stystems and the surroundings
the liklihood of a system failure increases with increasing complexity in the hardware
severity of a potential outcome increases if time for error correction is short, information to the operator is ambiguous or inderct, and subsystems are interconnected
Energy Release Theory of Accident Causation
accidents - energy and transference
to prevent accidents
* prevent build up of energy
* reduce initial amount of energy
* prevent release of energy
* control energy release
* separate energy release from objects
Behavior Theory of Accident Causation
behavior based- 7 principles
1. intervention
2. identification of internal factors
3. motivation to behave in the desired manner
4. focus on the positive consequences of appropriate behavior
5. application of scientific method
6. integration of information
7. planned interventions
BBS program should include
common goals
clear definitions
observational data
decisions based on data
feedback
review
Modern Causation Model
Injury (Result), Mishap (Accident) and Operating Error
Modern Causation Model Errors
Operating errors
Systems Defects
Command Error
Safety Program defects
Safety Management Error
Safety management error countermeasures
training
education
motivation
task design
Safety program defect countermeasures
revise information collection
collection
analysis
implementation
Command error defect countermeasures
training
education
motivation
task design
Systems defects countermeasures
SOPs
regulations
policy letters
statements
operating errors countermeasures
engineering
training
motivation
mishap countermeasures
PPE
barriers
separation
result countermeasures
containment
firefighting
rescue
evacuation
first aid
Near Miss Relationship
For every serious injury, there are 59 minor andd 600 near misses
Accident Investigation Prodecures
- Secure the scene
- Provide care to injured
- Isolate scene
- Assign tasks
- Preliminary briefing
- Visit accident site
- Inspect accident site
- Interviews
- Determination
- Check
- Most likely sequence of events
- Post investigation briefing
- Summary report
- Report distribution
Interviews
should be conducted as soon as possible following an accident
Methods to formulate an hypothesis regarding accident
principle agreement
principle difference
principle of concommitant variation
Gross Hazard analysis
rough assessment
potential causes
diagram
Job Safety Analysis
breaks jobs into steps and identifies hazards associated
Failure Mode and Effect Analsys
determine where failures occur
lists manner and mode of possible failures and effects of failures
Fault tree analysis
logic diagram
potential cuases of accident and reasons backward
tree diagram
Multilinear evens sequence
timeline chart of sequence of events
Investigation report should include
- cover page
- title page
- executive summary
- table of contents
- narrative
- conclusions and recommendations
Narrative body of report should include
background
account of accident
discussion/analysis
recommendations
summary
