My Class

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IE 419 Work Design Productivity and
Safety Dr. Andris Freivalds Class 21
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Basics of Accident Prevention(Heinrich,
Petersen, Roos Industrial Accident Prevention)

• Accident Prevention direct control of workers,
  machines, environment to prevent accidents
• Safety Management - long range planning,
  education, training to prevent accidents

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Accident Prevention Process
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Domino Theory (Identify Problem)
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Ex. 1 - Domino Theory

• Sparks from grinder ignite nearby gasoline
  causing operator to be burned.
• Lack of Control
• Basic Causes
• Immediate Causes
• Accident
• Injury

Multiple causation!
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Accident Causation
Unsafe Acts Unsafe Conditions





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Accident Iceberg
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3 Es of Accident Prevention

• Engineering redesign of job/workplace
• Education training
• Enforcement discipline, rules
• Accident Causation Models ?

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Life Change Unit Theory

• Accident probability is situational
• Overload taxes persons capacity
• Leads to accidents (or illness)
• gt300 ? 79 in 2 yrs
• gt200 ? 51 in 2 yrs
• gt150 ? 37 in 2 yrs

Rank Life Event Units
1 Death of spouse 100
2 Divorce 73
4 Jail term 63
6 Injury 53
27 End school 26
41 Vacation 13
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Motivation-Reward Satisfaction Model
(Identify Problem)
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Behavioral Based Training

• ABC approach
• A antecedents
• B behavior
• C - consequences

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Collect Data Analyze Data

• Systematic approach
• Who, what, where, when, how, why
• Inspection
• Job/methods analysis
• Worksite analysis
• Job Safety Analysis (JSA)
• (Look beyond direct causes!!)

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Job Safety Analysis (JSA)(Job Hazard Analysis,
Methods Safety Analysis,Critical Incident
Technique, Failure Mode and Effects Analysis
(FMEA), Hazard and Operability Study (HAZOP))

• Break down job into elements
• List them in sequential order
• Examine them critically
• Focus on
• Worker
• Method
• Machine
• Material

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(No Transcript)
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Ex. 2 - JSA

• Scenario Two inspectors smashed their toes when
  a stack of armor plate (36x24x? in), standing on
  end against workbench, slid to the floor. They
  were stacked there because of insufficient room
  to leave them on delivery pallet, towed from
  Receiving. Since each piece needed to Rockwell
  tested, the inspectors stacked the plates on end
  rather than laying them flat on the floor, which
  would require later lifting (NIOSH!!). Similar
  accidents had occurred earlier, but without
  injuries.
• Typical Solution

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Ex. 2 JSA cont (Old Method)
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Ex. 2 JSA cont (New Method)
Recommendation Adjustable, powered transporter
(two)
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Advantages of JSA

• Maps out all details
• Quick, simple, objective
• Compares old new methods
• Examines effects on production
• Analyze safety before accident occurs
• Leads into Fault Tree Analysis

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Select Remedy Decision-Making Tools - Hazard
Action Table
Conditions
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Ex. 3 - Value Engineering
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Value Engineering - Safety

• Define Factors
• Effect on safety
• Cost
• Morale
• Social/environment
• Choose Alternatives depends
• Determine Weights judgmental
• Rate each alternative by factor - relative
• Resulting Value (sum of products) selects proper
  alternative

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Risk Analysis Basics

• Basic premise/approach
• All risks can not be eliminated
• However, can reduce potential loss
• Go for max cost effectiveness
• Risk of loss increases with
• ? probability that hazard will occur
• ? exposure to the hazard
• ? consequences of hazardous event

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Risk Analysis - Procedure

• Assign numerical values to factors
• Multiply factors ? overall risk score
• Risk score is a numerical value
• Good for relative comparison (not absolute)

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Factor Values
Likelihood Values
Expected 10
Possible 6
Unusual 3
Remote 1
Conceivable 0.5
Impossible 0.1
Exposure Values
Continuous 10
Daily 6
Weekly 3
Monthly 2
Few/year 1
Yearly 0.5
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Possible Consequences
Possible Consequences Value Possible Consequences Value
Catastrophe (many fatalities, 108 damage) 100
Disaster (few fatalities, 107 damage) 40
Very serious (fatality?, 106 damage) 15
Serious (serious injuries, 105 damage) 7
Important (injuries, 104 damage) 3
Noticeable (first aid, 103 damage) 1
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Risk Score
Risk Situation Value Risk Situation Value
Very high risk, discontinue operations 400
High risk, immediate correction 200-400
Substantial risk, correction needed 70-200
Possible risk, attention needed 20-70
Risk?, perhaps acceptable lt 20
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Ex. 4 - Risk Calculation
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Ex. 5 - Risk and Cost Effectiveness
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Apply Remedy and Monitor

• Who applies remedy
• Safety specialist/engineer
• Line supervisors
• Workers
• Monitor effectiveness of accident prevention
• Close the feedback loop
• Variety of statistical approaches

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Accident and Injury Statistics

• Incidence (frequency) rate
• IR incidents x 200,000
• hrs exposure
• Severity rate
• SR days lost x 200,000
• hrs exposure

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Chi-Square Analysis

• ?2 ? (Ei Oi)2/ Ei Ei
  HixOT/HT
• M areas Ei expected
• Oi observed OT Total observed
• Hi hours worked in area i
• HT total hours worked ? m -1

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Ex. 6 - Chi-Square Analysis
Dept. CTD Hours IR Ei
A 22 900,000
B 4 600,000 1.3 7.4
C 10 1,400,000 1.4 17.4
Total 36 2,900,000 2.5 36

• ?2 ? (Ei Oi)2/ Ei

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Red Flagging Control Chart
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Red Flagging - Monitor