Hazards Analysis & Risks Assessment
By
Sebastien A. Daleyden
Vincent M. Goussen
Hazards Analysis & Risks Assessment
• Importance of safety in design
• Hazard analysis: What is it?
• An useful engineer’s tool: Designsafe
Importance of safety in design
Unintentional injuries
• Cost of $399 billion a year only in the USA;
• Fifth leading cause of death;
• Due to interaction between machines and
their environment and the way people live
and work
Engineers should more think about the
safety of the users...
Importance of safety in design
The main reasons why we should
more care about safety are:
 Time
 Costs
 Competition
 International Influences
 Capturing knowledge
 Product liability
Hazard analysis: What is it?
Objectives:
Tool for engineers and safety
practitioners to
• identify possible hazards,
• provide an evaluation of the risks,
• prompt alternative design solutions
to mitigate or control the risks to an
acceptable level.
Hazard analysis: What is it?
Hazard: Potentially dangerous condition, which
is triggered by an event, called the cause of
the hazard.
Risk: hazard that is associated with a severity
and a probability of occurrence.
Hazard analysis: What is it?
Hazard analysis: Identify all possible
hazards potentially created by a product,
process or application.
Risk assessment: It is the next step after
the collection of potential hazards. Risk
in this context is the probability and
severity of the hazard becoming reality.
Hazard analysis: What is it?
When performed:
Before the design begins.
Information used:
 Literature,
 Scenarios,
 Expert opinions,
 Personal experience.
Hazard analysis: What is it?
General risk assessment protocol :
Establish Analysis Parameters
Identify Hazards
Assess Risks
Derive Risk Rating
Reduce Risks
Verify Effectiveness
Document Results
Hazard analysis: What is it?
Establish Analysis Parameters
Identify Hazards
Assess Risks
Derive Risk Rating
Reduce Risks
Verify Effectiveness
Document Results
These parameters can be
limits of the machine or
design, limits on uses,
limits on the scope of the
analysis, or other limits.
Hazard analysis: What is it?
Establish Analysis Parameters
Identify Hazards
Assess Risks
Derive Risk Rating
Reduce Risks
Verify Effectiveness
Document Results
The nature of this step
lends itself to a team
approach such as
brainstorming.
Hazard analysis: What is it?
Establish Analysis Parameters
Identify Hazards
Assess Risks
Derive Risk Rating
Reduce Risks
Verify Effectiveness
Document Results
Two risk factors are used:
• severity of injury
• probability of occurrence
Hazard analysis: What is it?
Establish Analysis Parameters
Risk matrix:
Severity Category
Identify Hazards
Assess Risks
Derive Risk Rating
Reduce Risks
Verify Effectiveness
Document Results
Probability Level Catastrophic Critical
Marginal
Negligible
Frequent
High
High
Serious
Serious
Probable
High
High
Serious
Low
Occasional
High
Serious
Low
Low
Remote
Serious
Low
Low
Low
Improbable
Serious
Low
Low
Low
If the risk is determined to not be
acceptable, it is necessary to reduce
that risk by implementing protective
measures.
Hazard analysis: What is it?
Establish Analysis Parameters
Identify Hazards
Remedy actions are taken to
reduce risks following the hazard
hierarchy:
Assess Risks
Derive Risk Rating
Reduce Risks
Verify Effectiveness
Document Results
• Eliminate hazards through the design
 Protect
 Warn the user
 Train the user(s)
 Personal protective equipment
Hazard analysis: What is it?
Establish Analysis Parameters
Identify Hazards
Assess Risks
Derive Risk Rating
Reduce Risks
Verify Effectiveness
Document Results
This assessment verifies
that the remedy actions
have reduced the risks to
an acceptable level.
Hazard analysis: What is it?
Establish Analysis Parameters
Identify Hazards
Assess Risks
Derive Risk Rating
Reduce Risks
Verify Effectiveness
Document Results
The documentation can be added
to a technical file for future use.
Hazard analysis: What is it?
When to stop:
There is no zero risk, always some
residual risk remains.
If the residual risk is acceptable, then
the risk assessment process is
completed.
Hazard analysis: What is it?
Caution:
Any hazard, which is not identified, will not
be addressed by safety measures and will
not be detecting during testing.
Hazard not identified during this analysis
can create substantial risk to users of the
design.
Hazard analysis: What is it?
An efficient tool:
A new computer tool, named
Designsafe, specially designed to speed the
hazard analysis process has become
available.
It uses a task-based method to ensure all
hazards to users are identified.
An useful engineers’ tool: Designsafe
dse has developed a fast, easy-to-use tool for
engineers and safety professionals to incorporate
safety through design by:
 identifying hazards
 prompting engineers to think about hazards which
they otherwise might overlook
 conducting a risk assessment for identified hazards
 reducing risks in a structured method
 preventing accidents and reducing liability
An useful engineers’ tool: Designsafe
what it is...
 an engineering tool for improving product
designs and processes
 a systematic method for conducting a taskbased safety analysis
 a technique for eliminating and controlling
hazards
An useful engineers’ tool: Designsafe
what it does...
 gives designers a quick and easy tool to evaluate safety
issues through design
 permits quick assessment of engineer's change orders
to safety issues
 assists design engineers in completing a safety analysis
for their products/processes
 helps companies identify potential hazards and
provides methods for elimination
 prioritizes design activities related to risk
An useful engineers’ tool: Designsafe
what are the benefits...
 helps prompt remedy actions for existing hazards
 can be employed at all stages of the life cycle of a
design
 assists in obtaining the CE mark for assessing
European markets
 can be printed for documentation or a technical file
 helps assure all hazards are addressed to completion
An useful engineers’ tool: Designsafe
what are the limits...
 It’s a guide, not an expert system;
 Poor inputs or incomplete data lead to poor results.
What could be the next steps ?
Fault Tree Analysis (FTA)
• a powerful diagnostic tool for analyzing
complex systems,
• begins with selecting the “top event”,
• repeating this process at successive levels
using standardized symbols identifies
primary and secondary faults.
What could be the next steps ?
Failure Modes and Effects Analysis
 identifies potential product modes which could
lead to accidents,
 breaks down designs into components or
subcomponents, then systematically evaluates
the potential for and effects of individual
failures,
 results of the analysis are used to evaluate and
implement preventive measures to eliminate or
control hazards.