Risiko COPY Flashcards

1
Q

What is risk?

A

Risk = combination of consequences and associated uncertainties

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2
Q

What are the risk concept and its denotation

A

(C, U) = Consequences with respect to something of value
OR
(A, C, U) = Consequences with respect to something of value, given the event A

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3
Q

What is the general risk description and what is Risk described by?

A

Risk description = (A’, C’, P, SoK, K)
Risk is described by = (C’, Q, K) and (A’ C’, Q, K)

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4
Q

What do the different variables mean?

A

A’ = Specified events
C’ = Specified consequences
Q = Uncertainty measure describing uncertainties related to A’ and C’. Commonly represented by (P, Sok).
P = Probability
SoK = Strength of knowledge
K = Knowledge that Q and (A’, C’) are based on.

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5
Q

Describe some common risk metrics

A

E[C’] = Expected value
Ef[C] = Average value of return if one runs a project an infinite (or large) amount of times.
VaR = Value at Risk
PLL = Potential loss of lives in a period of one year
FAR = Fatal accident rate. Expected number of fatalities per 100 million exposed hours.

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6
Q

What are the formulas for PLL and FAR?

A

PLL = n * IR
n = number of equally exposed individuals
IR = probability that a specific person is killed in a year

FAR = Fatalities pr. exposed hour * 100 million
OR
FAR = (PLL / Number of exposed hours) * 100 million

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7
Q

Define a frequentist probability

A

Pf(A) = Number of times A would occur when repeating situations over and over nearing infinite.

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8
Q

Define subjective/knowledge-based probability

A

A probability expresses a person’s uncertainty or degree of belief that an event will occur. The person compares the uncertainty or belief related to event A.

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9
Q

What is a crucial assumption related to the underlying value in frequentist probabilities?

A

The value needs to be estimated as the underlying true value is generally not known.

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10
Q

Define Resilience

A

The ability of a system to sustain or restore its basic functionality following an event (risk source).

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11
Q

Define Vulnerability

A

Vulnerability is essentially risk conditioned on the occurrence of an event A.

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12
Q

What is the description of vulnerability?

A

Vulnerability = (C, U|A)

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13
Q

What is the connection between Resilience and Vulnerability?

A

Resilience reflect an aspect of vulnerability by focusing on the systems ability to recover after an event A.

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14
Q

Define Reliability

A

A system’s ability to work as intended

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15
Q

In what way is safety the antonym of risk?

A

High safety = Low Risk
Low Safety = High Risk

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16
Q

What does the term “Safe and secure” mean in practice?

A

The term “Safe and Secure” means that the risk is acceptable/tolerable

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17
Q

What is a Risk matrix? And, what are some of its common limitations?

A

Risk matrix:
Matrix that illustrates risk by different events, using the probability of the event ( P(A’) ), and conditional expected value ( E[C’|A] ).

Limitations:
*Does not reflect the spectre of consequences and lacks considerations of the SoK
*Often, are events poorly plotted and not well defined
*Colour schemes should generally be avoided as they are potentially misleading
*Consequences of an event are not properly represented by one point in the matrix.
*Two events could have same location in matrix, but have vastly different supporting knowledge and consequences.

18
Q

What is a Risk assessment?

A

Methods and approaches for improving our understanding of risks and supporting decision-makers.

19
Q

What is the benefit of a risk assessment?

A

Risk assessments can help identify what may go wrong, why and how, what are the consequences and how bad are they.

20
Q

What are the different stages in a Risk assessment?

A
  1. Planning - Establishing context
  2. Risk analysis & Risk Evaluation
  3. Utilization of risk assessment
21
Q

Explain what the term “management review and judgement” (MRJ) is

A

MRJ is the process between a risk assessment and consequent decision-making.
The MRJ process considers the limitations of the risk assessment. One summarises, interprets and deliberate the risk assessment results such that the results are prepared for decision makers.

22
Q

What is a model-based risk assessment? What is their purpose?

A

Model-based risk assessments are used to understand how a given system functions.
They aim to increase risk understanding by allowing us to change input quantities and measure the effect of risk-reducing measures.

23
Q

List the different examples of model based risk assessments

A
  • Event trees - Assess possible outcomes, associated probabilities
  • Fault trees - Assess the probability of failure in a safety barrier.
  • Block diagram
  • SWIFT - Identify the events leading up to a later event
  • FMEA - Identify and rank failure modes for a system
24
Q

What are the basic symbols in a fault tree, and what is their meaning?

A

Circle - Basic event - Event at the lowest level in the model
Bowed square - And gate - The output event (above) occurs if all outputs (below) occur.
Bowed Triangle - Or gate - The output event (above) occurs if at least one of the input events (below) occurs.
Triangle - Transfer symbol - Used when the same branch occurs at several places in the tree, and when the tree must be drawn on several pages.
Rectangle - Description of event/state - Placed above gates and basic events.

25
Q

What is the connection between a fault tree and a block diagram in terms of reliability and unreliability?

A

Fault tree perspective: What does it take for the system to fail (Top event to occur?)

Reliability block perspective:
Unreliability - What does it take for the system to fail? (Cannot move from left point to right point)
Reliability - What does it take for the system to work (Get from left point to right point)

26
Q

What is the denotation used for the reliability and unreliability of a component?

A

pi = Probability of a component i working (reliability of component i)

qi = Probability of a component i not working (the unreliability of component i)

27
Q

What is the purpose of a event tree analysis?

A

Event tree analyses are used to study the consequences of initiating events.
Can be used qualitatively and quantitatively.

28
Q

Explain the term risk perception

A

Risk perception is a person’s subjective judgement of risk, considering social, cultural and psychological factors.

Risk perception relates to feelings, including fear, but can also cover conscious judgements related to risk.

29
Q

Describe the model used to describe the level of general trust and level of scepticism.
Also, describe the content in the model.

A

The model ranks the level of “general trust” and “Level of Scepticism” as high or low.

Low general trust / Low scepticism - Distrust
Low general trust / High scepticism - Rejection (Cynicism)

High general trust / Low scepticism - Acceptance (Trust)
High general trust / High scepticism - Critical trust

30
Q

What is risk communication, and what is its purpose?

A

Risk communication relates to communicating, exchanging or sharing risk-related information with different groups.

Risk communication aims at improving risk understanding to make appropriate risk-related judgements and decisions.
Also, it has the following functions:
* Enlightenment
* Right-to-know
* Attitude change
* Legitimation
* Risk reduction
* Behavioural change
* Emergency preparedness
* Involvement
* Participation

31
Q

What does the abbreviation “SARF” mean?

A

SARF = Social amplification and attenuation of risk

32
Q

What is SARF?

A

SARF is a framework that includes both technical risk assessments with psychological, cultural and institutional perspectives.

33
Q

Define risk management

A

Risk Management = All activities used to address risk

34
Q

Deliberate on the main strategies for managing risk

A

The strategies should be used in accordance with the relevant context
1. Being risk-informed
2. Acting in accordance with the Cautionary/Precautionary principles
3. Discursive strategies

35
Q

Explain the cautionary principle

A

If an activity’s consequences are potentially severe and subject to uncertainties, cautionary principles are appropriate; otherwise, the activity should not be carried out.

36
Q

Explain the precautionary principle

A

If an activity’s consequences are potentially severe and subject to scientific uncertainties, then precautionary measures should be taken, or the activity should not be carried out.

37
Q

What is a Cost-Benefit Analysis (CBA), and what is the main drawback of this analysis?

A

A CBA is a type of analysis used to calculate the expected net present value of a measure.

38
Q

Name and explain the various figures closely related to a CBA?

A

Expected Net Present Value:
E[NPV] = Expected benefits - Expected costs
OR
E[NPV] = Expected number of lives saved * VSL - Expected cost

VSL = Value of a statistical life - The max value we are willing to pay to reduce the expected number of fatalities by 1

E[NPV] Rules:
E[NPV] > 0 = Implement measure
E[NPV] < 0 = Don’t implement measure

39
Q

Explain what a Cost-effectiveness analysis is

A

A analysis used to calculate the effectiveness of a measure (Often risk reducing measure)

40
Q

What is the formula for determining a cost-effectiveness ratio, and what what is ICAF?

A

Cost-effectiveness ratio (ICAF) = E[expected cost of measure) / E[expected benefit)

41
Q

Define Risk Science

A

Risk Science = The most justified (best) knowledge (and practice of acquiring knowledge) related to risk assessment, communication, and handling.

42
Q

Risk science is divided into two sub-categories. Name and explain the two sub-categories.

A

Applied Risk Science:
This relates to supporting risk knowledge generation in relation to specific activities and handling specific risk problems

Generic Risk Science:
Generic risk science relates to generic risk concepts, principles, approaches and methods on how to understand, assess, characterize, communicate, manage and govern risk.