Jouni KivistRahnasto

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Content

• Risk analysis
• Risk analysis, Risk assessment, Risk management
• Risk analysis methods
• 2. Qualitative risk estimation
• Nominal
• Ordinal (qualitative)
• Ordinal (semi-quantitative)
• Example Occupational health and safety risk (BS
  8800 2004)
• 3. Quantitative risk estimation
• Frequency or probability severity of
  consequences
• Simple examples
• Fourth home work

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1. Risk analysis

• Risk analysis, Risk assessment, Risk management
• Risk analysis methods

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Risk analysis, Risk assessment, Risk management
Thread identification Identify harmfull
events and existing risk controls
Risk analysis
Risk estimation Estimate frequency severity
Risk assessment
Risk evaluation Define acceptance criteria and
apply it
Risk management
Alternative options and decision making
Planning and implementing risk controls
Follow-up
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• Essential questions (Kaplan Garrick)
• What can go wrong?
• How likely is it?
• What are the losses (consequences)

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Risk analysis methods

• Look for example book part 2.3 Risk analysis
  methods
• Some methods
• Studies (surveys, interviews, statistics, etc)
• Checklists
• Brainstorming
• SWOT (strengths, weaknesses, opportunities,
  threads)
• PPA (Potential problem analysis)
• FMEA (Failure mode and effect analysis
• HAZOP (Hazard and operability analysis)
• Modeling
• Event tree
• Scenarios
• Failure tree
• Monte-Carlo simulation
• Delphi
• etc.
• Top down approach

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2. Qualitative risk estimation

• Nominal
• Ordinal (qualitative)
• Ordinal (semi-quantitative)
• Example Occupational health and safety risk (BS
  8800 2004)

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Nominal
8
Ordinal (qualitative)
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Ordinal (semi-quantitative)
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Example Occupational health and safety risk(BS
8800 2004)
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Unacceptable
Conditionally acceptable
Acceptable
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(No Transcript)
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3. Quantitative risk estimation

• Frequency or probability severity of
  consequences
• Simple examples

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Frequency or probability severity of
consequences Risk

• R ?SiPiCi? i 1,2, , n
  (Modarres 2006)
• Si Scenario of events the lead to hazard
  exposure
• Pi Likelihood of scenario i
• Ci Consequence of the occurred scenario i
• Generally
• R ?fici
• f Frequency of scenario i
• c Consequence of scenario i
• We are aiming to estimate
• Frequency, or
• Events/time
• Probability, and
• P(Event) (e.g. probability that scenario occurs
  within the following year)

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Very simple example 1
Frequency of an accident is 3/10 years-1 Cost
of one accident is 20 000 What is the
financial risk for the following 5 years?
R ?fici
3
R 5 years X
X
20 000
10 years
R 30 000
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Very simple example 2

• Probability Pplc that an product fails within
  its lifetime and causes product liability claim
  is 10-3. ( no class actions!)
• Total volume N of the production is 109 pieces
• Costs c of single claim is 500
• What is the expect total product liability cost
  for the product?
• R ?fici
• f Pplc N 10-3 109 106
• c 500
• R 106 500
• R 500 000 000
• What do you think Can we accept or tolerate the
  risk?

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Very simple example 3
In Finland, 6700 traffic accidents occur
annually. One accident out of 20 is fatal. How
many people do we loos annually?
R ?fici
(
)
(
)
(
)
Consequence
Event
Consequence
Risk

Frequency
Consequence
X
Time
Time
Event
(
)
(
Accident
)
(
)
Death
Death
X
Risk

Year
Accident
Year
(
)
(
(
6700
)
)
Death
1
X
Risk

Year
Year
20
(
)
335
Death
Riski

Year
Year
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What did we learn about the qualitative risk?

• The magnitude of risk can be estimated in various
  ways! e.g.
• Total costs of events
• Deaths/year
• Expected loss of lifetime
• Number of lost customer
• Etc.

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Fourth home work
Bulb
Switch
Fuse
Wire
Plug
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See the book 2.3.7.4.2 Fault-Tree and
Success-Tree Analyses2.3.7.2 Failure Mode and
Effects Analysis

• The bulb is not lighting
• What are the alternative causes for the problem?
• Use Fault tree analyse to solve the problem
• Analyse the system by FMEA (failure mode and
  effect analysis)