MEM 604: Social, Legal and Ethical Considerations for Engineering

MEM 604: Social, Legal and Ethical Considerations for Engineering

Managing Safety and Liability

Anticipatable Risk?Anticipatable Risk?

• How would an engineer assess the differences between the 1945 crash of a B-25 into the Empire State Building and the attack by 727s on the World Trade Center?

• What is the significance of the efforts to weaken building codes and apply untested design principles to maximize commercial prospects?

• Could they or should they have anticipated the possibility of the terrorist attacks?

Liability and SafetyLiability and Safety

• Risk is an ineliminable feature of engineering.• That is true for the use of well established

principles and substances.• It is particularly true for innovative techniques and

products.• In response, engineers are required to:

• anticipate and estimate risk;• be conscious of their willingness to tolerate risk;• define acceptable risk;• be aware of the principles of legal liability.

Starting with the CodesStarting with the Codes

• For engineers, the natural place to start a discussion of safety and risk is with the various codes of ethics that govern professional behavior.

• These codes of largely consistent in placing a high premium on safety. In as much as safety and risk are inversely related to each other, the more substantial the safety measures in place the smaller the risk, and vice versa.

Codes and SafetyCodes and Safety

• Though the codes consistently require engineers to emphasize safety in their designs and oversight responsibilities, as is typical with codes, the generality of their guidance may not be sufficiently action guiding.• Cf. NSPE code, p. 292-3.

• In addition to general concerns for safety, another common element of Codes is emphasis on the significance of informed consent.

• As part of commonly accepted practice is the notion of “factors of safety.”

Local CodesLocal Codes

• In addition to professional codes, engineers are obligated to design in conformity to local codes.

• Failure to do so is a significant moral and legal failure.

• Additionally, engineers who identify limitations in existing codes have an obligation to pursue changes to the code.

The Challenges of Risk AssessmentThe Challenges of Risk Assessment

• As clearly as we can specify an engineer’s obligation to public welfare, there is nonetheless often considerable ambiguity in correctly assessing safety implications.

• This is largely due to the difficulty of assessing risk.

• Though we can never remove the uncertainty of the activity, there are a number of techniques that can be employed to reduce it.

Defining Some ConceptsDefining Some Concepts

• Risk: “the product of the likelihood and the magnitude of the harm” (137).

• Harm: “an invasion or limitation of a person’s freedom or wellbeing” as measured in human or material terms (Ibid).

• The definitions of both terms make clear why some expertise is helpful in assessing risk and safety issues.

Laypersons and RiskLaypersons and Risk

• Humans are notoriously bad at estimating risk. Experts have a real advantage here.

• Non-Experts do not as carefully isolate their evaluation of risk from their consideration of other potentially relevant factors.

• To some extent, the differences may be attributable to ignorance, but to a large extent they are doubtless attributable to different contexts of evaluation.

Normal Accidents?Normal Accidents?

• The difficulties attendant on risk assessment has led some to argue that we need to stop thinking of accidents as anomalies and begin to understand them as part of the normal course of affairs.

• This particularly true of high risk technologies, due to two factors: • Tight Coupling: processes closely linked.

• Complex Interactions: interactions between elements difficult to predict.

Normalized DevianceNormalized Deviance

• The challenge posed by high risk technologies can be exacerbated by the tendency of people familiar with the risks to tolerate it.

• The tolerance has been labeled Normalized Deviance.

• Something like this seems to be at the root of the Challenger disaster.

Experts, Utilitarianism and RiskExperts, Utilitarianism and Risk

• For the expert, some version of Utilitarian analysis is usually employed to identify acceptable risk.

• From this perspective, acceptable risk can be defined as, “…one in which, given the options available, the probability of producing harm is at least equaled by the probability of producing benefit” (138).

• The problems with this approach are essentially the same problems that utilitarianism itself is faced with (measurement, justice).

• One response has been what the editors of the text identify as “The Capabilities Approach,” in which vague concepts of utility are replaced with more readilly apreciable concepts of human capacity.

• Laypersons are usually more committed to a Respect for Persons approach.

• Key to such an approach is the concept of Informed Consent

• Informed consent occurs when three conditions are met:• No coercion;• Relevant information is provided;• Rational and competent evaluation is possible.

Respect for Persons: Informed ConsentRespect for Persons: Informed Consent

Respect for Persons: JusticeRespect for Persons: Justice

• At the heart of the notion of informed consent is a concern for justice. It doesn’t seem right that some individuals should bear the burden for the group.

• For the layperson, acceptable risk can be defined as, “…one in which risk is assumed by free and informed consent, or properly compensated, and which is justly distributed” (170).

Acceptable Risk?Acceptable Risk?

• The concepts of Normal Accidents and Normalized Deviance underscore the sense in which we must all be willing to accept some level of risk.

• The question becomes: What is acceptable risk?

• There are a couple of different techniques we can review which can help us resolve this question, when it arises.

Fault TreesFault Trees

• One method that engineers can use to help them identify and assess risks is the Fault Tree.

• A fault tree is a diagram specifying the failure modes of a system.• Failure Mode: a way in which a system, structure or process can

malfunction (156).

• They aid in the systematic analysis of the failure modes of a project, to the extent that they can be anticipated.

Example of a Fault TreeExample of a Fault Tree

• www.relexsoftware.com/ resources/art/art_fta.asp

Event TreesEvent Trees

• Another device that can be used to help identify and assess risks is called an Event Tree.

• An event tree is a diagram which traces out the possible implications of a hypothetical system, structure or process failure.

• The advantage of such diagrams is their ability to include quantitative analysis of risk.

Example of an Event TreeExample of an Event Tree

• http://www.adventengineering.com/images/Other_images/NucEventtree.gif

Problems with these TechniquesProblems with these Techniques

• Both of these methods have important limitations.• It is difficult to anticipate all of the failure

modes.• It is difficult to anticipate all human errors.• It is difficult to assign probabilities to all of the

possible events.

Engineers and LiabilityEngineers and Liability

• Standard of Proof in Tort Law: Preponderance of the Evidence.

• Guiding Legal Principle in Liability Cases: Proximate cause.

• Despite these (low) standards, tort law may still not provide enough protection for consumers or end-users of a product.

What Should You Do?What Should You Do?

• The editors articulate a principle of acceptable risk which can be useful when risks are morally acceptable (160).

• They highlight a number of issues that may or should constrain the use of the principle in specific cases.

• The key is that any such principle can only do so much for us. We still have to do the hardwork of analysis and evaluation.