UNIT III

ENGINEERS RESPONSIBILITY FOR SAFETY

THREE CATEGORIES OF CONSUMERSActive consumers Who have control in choosing the item or the manner in which it can be used safely.

Passive consumers Who have less choice and less control over the use.

Bystanders Who are exposed to dangers even without using them.

DEFINITIONSSafety- The ability to make or keep something safe.A thing is safe if its risks are judged to be acceptable John A Shedd.

Risk- The potential that something unwanted or harmful may occur. It is the possibility of meeting a danger or suffering harm or loss.

CONCEPT OF SAFETYUnder-estimation of risk An unsafe product may actually be considered to be safe enough, because of the wrong judgment of the user.Over-estimation of risk Even if a product is comparatively safe and risks are less, some consumers may be overcautious, or over consciousness about safety.No estimation of risk Do not make any judgment at all about the risk.

RISKRisk in technology could include dangers of bodily harm, economic loss, or environmental degradation.Safety is a concrete concept, while risk is a vague, hypothetical concept Risk is reality and safety is fantasy

DEGREE OF RISK ACCEPTABILITYAcceptability of RiskA risk is acceptable when those affected are generally no longer apprehensive about it.

Voluntarism and ControlA person is said to take voluntary risk , when he is subjected to risk by either his own actions or actions taken by others

Effect of Information on Risk AssessmentsEg. 600 livesCase 1 is adopted: 200 people will be savesCase 2 : 1/3 probability that 600 people will be saved, and 2/3 probability that no people will be saved?Which will you opt for?

Case 3: 400 people will dieCase 4: 1/3 probability that nobody will die, and 2/3 probability that 600 people will die.Which of the two cases would you favour?Job related RisksMagnitude and Proximity

TYPES OF ACCIDENTSProcedural Accidents Are the result of someone making a bad choice or not following established standard procedures.

Engineered Accidents Caused by the errors in the design.

Systematic Accidents - Are difficult to understand and difficult to control.

DETERMINATION OF RISKKnowledge of RiskUncertainties in DesignTesting for Safety

KNOWLEDGE OF RISK

To assess a risk, an engineer must first identify it.

To identify a risk, an engineer must first know the information about the safety of standard products.

UNCERTAINTIES ENCOUNTERED IN DESIGN PROCESS

A decision on maximizing profit or maximizing the return on investment.Applications like dynamic loading instead of static loading, vibrations, wind speeds.Materials and skills required in the manufacturing.Changing economic realities.Unfamiliar environmental conditionsThe available standard data are based on statistical averages only.Due to the inherent nature of processes, all components have a tolerance in design leading to the probability statistics by which assemblies capability is assessed.

TESTING METHODS FOR SAFETYScenario Analysis Starts from a given event, and then studies the different consequences that might develop from it

2. Failure modes and Effects Analysis Examines the failure modes of each component without focusing on causes or relationships among the elements of a complex system.

3. Fault- Tree Analysis Proposes a failure system and then traces the event back to possible causes at component level

4. Event Free Analysis This is the reverse of the faulty free analysis

FACTORS ON WHICH RISK DEPENDS UPONWhether the risk is voluntary or involuntary?Whether the risk is immediate or delayed?Whether the consequences are of short term or of long term?The expected probability of occurrenceWhere the effects are reversible or not?Personal or public riskThe threshold level of the riskInformation availableOccupational risks

RISK ASSESSMENTA risk assessment is simply a careful examination of what, in your work, could cause harm to the people, so that you can weigh up whether you have taken enough precautions or should do more to prevent harm.

RISK BENEFIT ANALYSISA method of analysis that helps an engineer to determine whether to proceed with a project or not is the risk benefit analysis. What are the benefits of the project / products?Is the project / product worth the risks connected with its use? Do benefits outweigh the risks?

DIFFICULTIESBoth risk and benefits are very difficult to quantify.. Becoz of uncertaintiesWho takes the risk and who enjoys the benefits?Difficult to express both risk and benefits in a common set of units.

ETHICS IMPLICATIONS IN RBAUnder what conditions, someone in society is entitled to impose a risk on someone else on behalf of a supposed benefit to others?

How can we consider the worst case scenario of persons exposed to maximum risk while they are also obtaining only minimum benefits?

Are their rights violated? Are they provided safer alternatives?

PERSONAL RISK

Making judgments on the basis of the amount of life insurance taken out by an individual

Assessing a hazardous job by looking at the increased wages a worked demands to carry out the taskPUBLIC RISK AND PUBLIC ACCEPTANCEACCOUNTING PUBLICLY FOR BENEFITS AND RISKBECOMING A RESPONSIBLE ENGINEER REGARDING RISK

REDUCING RISKRisk Management : May be defined as the eradication or minimization of the adverse effects of the pure risks to which an organization is exposed.Elements of a risk management programme: Risk identificationRisk evaluationRisk control

Risk identification Physical inspection, safety audit, job-safety analysis, management and worker discussions, historical data analysisRisk Evaluation - measured on the basis of economic, social and legal considerationsRisk Control Risk avoidance to avoid the task by discontinuing the operation producing the riskRisk retention Retaining a particular risk for which any consequent loss is financed by the organizationRisk transfer - InsuranceRisk Reduction Reduction or elimination of all aspects of accidental loss that lead to a wastage of an organizations assets.

THE GOVERNMENT REGULATORS APPROACH TO RISKRegulators could decide to regulate only when there is a provable connection between a substance and some undesirable effect.Regulators could eliminate any possible risk insofar as this is technologically possible.An acceptable risk is one in which protecting the public from harm has been weighted more heavily than benefiting the public

COMMUNICATING RISK TO THE PUBLIC1. Should be aware that the publics approach to risk is not the same as that of the risk expert. In particular, risky cannot be identified with a measure of the probability of harm. Thus, engineers should not say risk when they mean probability of harm. They should use the two terms independently.2. Engineers should be wary of saying, There is no such thing as zero risk. The public often uses zero risk to indicate not that something involves no probability of harm but that it is a familiar risk that requires no further deliberation. 3. Engineers should be aware that the public does not always trust experts and that experts have sometimes been wrong in the past. Therefore, engineers, in presenting risks to the public, should be careful to acknowledge the possible limitations in their position. They should also be aware that laypeople may rely on their own values in deciding whether or not to base action on an experts prediction of probable outcomes.

4. Engineers should be aware that government regulators have a special obligation to protect the public, and that this obligation may require them to take into account considerations other than a strict costbenefit approach. Although public policy should take into account costbenefit considerations, it should take into account the special obligations of government regulators.

5. Professional engineering organizations, such as the professional societies, have a special obligation to present information regarding technological risk. They must present information that is as objective as possible regarding probabilities of harm. They should also acknowledge that the public, in thinking about public policy regarding technological risk in controversial areas (e.g., nuclear power), may take into consideration factors other than the probabilities of harm.

*M.Anupama, AP-EEE, PCET*