Operating
Hazards Analysis
Chapter 17
Operating Hazards Analysis
Examining the human – machine –
operations relationship
Procedure Analysis
 Set of sequenced actions for:
 Operating
 Assembling
 Maintaining
 Repairing
 Calibrating
 Testing…
Procedure Analysis
 Set of sequenced actions for:
 Transporting
 Handling
 Installing or
 Removing…
a product, assembly or component
Procedure Analysis
 Completion of tasks does not expose personnel to
hazards
 Instructions are clear & effective & don’t introduce
errors
 Alternative actions are precluded or effects are
minimized
Procedure Analysis
 Safety-critical steps highlighted with warnings &
cautions
 No extraordinary mental / physical demands
 Realistic times for accomplishment of safety-
critical tasks
Outputs
Proper procedure analysis generates the following outputs:
 Corrective / preventive measures
 Recommendations for changes or improvements in
hardware / procedures
 Development of warning & caution notes
 Requirements for special information / training
 Recommendations for special equipment
Procedures Verification
 Verify procedures after analysis
 Verification done by someone not involved in
writing / analyzing procedures
 Person verifying procedures may use checklist
similar to one on page 95 (Figure 10-10, Human
Factors Checklist)
Contingency Analysis
 Definition: Emergency / potential emergency
caused by occurrence of unprogrammed event
which exists as a transitional stage between
normal operation & an accident
 Actions during first few minutes after losing
control over hazard may determine whether or
not control can be re-established & accident
avoided
Contingency Severity
Depends on:
 Magnitude of affecting condition
 Ability of product to withstand condition
 Configuration at time of occurrence
 Available reaction time
 Operator capability re: corrective action taken
Contingency Analysis
During emergency may not be enough time for
proper reaction if one must simultaneously
determine:
 What is wrong
 Best corrective action
 How to carry out decided action
Contingency Analysis
During critical unexpected emergency:
 Controlled individual is under stress
 Degraded ability to react calmly & suitably
 Multi-tasking in short time frame overwhelming &
usually unsuccessful
 Successful rectification rests in previously
developed & tested procedures
Contingency Analysis Procedure
1. Select contingency to be investigated
2. Sketch sequence / chain of events which
might occur during contingency
Contingency Analysis Procedure
3. Analyze chain of events to determine if possible
action exists to forestall each event
4. Select corrective actions to adopt - one or more
depending on end effect (minor or catastrophic)
5. Ensure corrective actions will be effective &
reliable
Contingency Analysis Procedure
Items to Consider:
1. Product vulnerability
2. Direction & warning methods
3. Corrective actions
Contingency Analysis Procedure
4. Points of no return
5. Emergency equipment
6. Safety & evacuation routes