Lecture 7: The Engineer

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Lecture 7 The Engineers Concern for
Safety(Chapter 4, Martin Schinzinger, Ethics
in Engineering)

• ELEC4011 Ethics Electrical Engineering Practice
• Hugh Outhred

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Contents

• Ethical basis for concern for safety
• Concepts of safety risk
• Risk and decision making
• Variability in attitudes to risk
• Socially responsible engineering
• Risk management
• Design for safety
• Facilitate informed choice by user

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Safety

• Safety of one or more human beings
• Absence of harm
• Relative, not absolute
• To live involves an irreducible level of risk
• Assessment of safety by an individual or group
• Requires
• Unbiased interpretation of all relevant
  information
• Appropriate skills to develop an informed opinion
• Sufficient time to reach a (consensus) decision
• Outcome an assessment of relative safety

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Risk

• Potential for an unwanted outcome from an action
• e.g. physical injury to one or more people
• Two aspects
• Nature of unwanted outcome(s), e.g
• Physical injury
• Negative impacts on quality of life
• Environmental damage
• Uncertainty surrounding outcomes
• Sometimes this can be quantified
• Useful test how much would I regret each
  possible outcome?

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Some sources of uncertainty

• Manufacture
• Design errors, component quality, assembly errors
• Installation operation
• Installation errors cost over-runs
• Equipment failure, operator error, volatility in
  input costs, external factors such as weather
• End of life
• Dismantling and disposal costs and impacts

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Two views of uncertainty

• Statistical viewpoint
• Events determined by stable probability
  distributions
• probability distributions may be derived from
  statistical analysis of past experience in
  similar situations
• Hence risk is an objective issue
• Scenario viewpoint
• Past behaviour not a reliable guide to the
  future
• Technological, social and environmental change
• Expectations influenced by social corporate
  culture
• Hence risk is a subjective issue

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Utilitarianism risk
Cost
Risk
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Risk-response matrix
Manage for continuous improvement
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Practical moral issues

• Complete safety impossible
• How safe is safe enough?
• Are risks distributed differently from benefits?
• Quantification of indirect costs can be
  difficult
• Value of human life?
• What indirect costs should be considered?
• Minimum total cost might exceed socially
  acceptable risk
• Who should decide?

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Individual attitudes to risk

• Attitudes influenced by a range of factors
• Voluntary versus involuntary
• Controllable versus uncontrollable
• Work-related versus recreational
• Severity of potential harm
• Extent of relevant knowledge skills
• Individual preferences
• Attitudes dont always appear rational
• Should this affect our respect for them?

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Societal attitudes to risk

• Obscured by the diversity of individual attitudes
• Must be assessed indirectly
• Expert groups
• Public interest advocacy bodies
• Focus groups (random or targeted selection)
• Judicial determination
• Societal norms develop from a history of
  litigation
• Social attitudes evolve through time
• Continuing need for informed consent

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Safe exits prudent avoidance

• Safe exits (last lines of defence)
• Equipment fails safely or can be abandoned
  safely
• dead-mans handle for train drivers,
  safety-belts, airbags
• User can escape safely
• e.g. aircraft parachutes and/or escape slides
• Prudent avoidance (a quasi-legal obligation)
• Avoid unjustified risk to other people
• Both may require coordination between
• Designers, managers, users the public

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Conclusions

• Engineers have a concern for safety
• Duty to equipment users and the public
• Issues in considering risk safety
• Subjective, with variations in individual
  assessment
• There is often a trade-off between safety cost
• Tools for arriving at a reasonable balance
• Public involvement in decision making
• Risk management in design
• Safe exits and prudent avoidance