Engineering Ethics : Chapter 5 4j35p

*No duty of the engineer is more important than her duty to protect the safety and well-being of the public . *In this chapter,we will look into safety and risk. We will also examine the nature of accident and try to determine what the engineer’s role is in preventing accidents and ensuring the safety of the public.

The engineering codes of thics show that engineers have a responsibility to society to produce product that are safe. There is an implied warranty that products are safe to use .clearly, nothing can be 100% safe, but engineers are required to make products as safe as reasonably possible. Thus,safety should be an integral part af any engineering design.

Safety is at the same time avery precise and a very vague term . Vague because safety is avalue judgment Precise because in many cases we can readily distinguish a safe design from an un safe one *It is impossible to discuss safety wiyhout including adiscussion of risk *Risk is akey element in any engineering design *it is impossible to design any thing to be completely risk free.

*Safety and risk are essentially subjective and depend on many factors:

1- voluntary vs involuntary, Many consider something safer if they knowingly take on the risk , but would find it unsafe if forced to do. 2- short-term vs long-term consequences . Something that might cause a short illness or disability seems safer than something that will result in permanent disability.

3- Expected probability. Many might find a 1 in 1,000,000 chance of severe injury to be an acceptable risk , whereas a 50:50 chance of fairly minor injury might be unacceptable (it is important to here that the expected probability is only an educated guess) 4- Reversible effects. Something will seem less risky if the bad effects are ultimately reversible.

5- Threshold levels for risk. Something that is risky only at fairly high exposures will seem safer than something with a uniform exposure to risk. *if there is a threshold for the effect, generally there will be a greater tolerance for rsik. 6- Delayed vs immediate risk, an activity whose harm is delayed for many years will seem much less risky than something with an immediate effect.

Thus, whether something is unsafe or risky often depends on how asked , this create some confusion for the engineer who decide ,so in making a decision ,some analysis methods, especially line drawing and flow charting, can be used to help the engineer to take right decision for safety.

There is no important duty for an engineer more than the safety of the public.

Safety is an essential aspect of an engineering responsibilities.

To ensure the safety of an engineering design, four criteria must be met.

The engineering design must comply with the applicable laws.

This requirement must be easy to meet, because the legal standards of safety are well known, published and easy accessible .

The second rule says that the acceptable design must meet the standards of accepted engineering practice.

You can’t create a design that is less safe than what everyone else in the profession understands to be accessible.

An example on the 2nd rule: In a power supply design, the federal safety laws might not require that the design be inaccessible to a consumer who opens up a computer.

If manufactures designed the supplies so that no lethal voltages can reach the , then that design is considered to be standard and to be followed by all designer even if it increases the cost.

A real-life example is the DC-10 case. The airframe was adapted from another design, but wasn’t in accordance with the aircraft manufacturing. This requirement is harder to comply with the standards because the concept of accepted engineering practice is somehow not applicable!!

The 3rd rule says that any design alternatives that are potentially safer must be explored.

This requires some creativity in seeking alternative solutions.

With some creativity, you can discuss strategies for the design with specialists in your field and discover new strategies with them

The 4th rule says that the engineer must be aware of potential product misuses by the s and the design should be to avoid these misuses.

As stated before, this requires some creativity. But if the is too stupid to use the design, don’t bother your self too much!!

Once the product is designed, both prototypes and devices should be tested.

This test ensures both functionality and safety of the design.

And to be aware, these tests should not be only for testing and ensuring functionality.

How Should Safety Help In Engineering Design Process? One version of this process is found in Wilcox [1990] and is summarized as follows:

We should define the problem first.. Know What Caused It?.. And What The Possible Solutions for it! This Step include determining the needs and requirements and sometimes the constraints.

We here determine how the solutions meets the specifications and multiple alternative design are created.

*We have to determine the pros and cons of each solution. * Here we determine the consequences of each design solution and determining whether it solves the problem or not. *To know what will be the cost for each solution.

We must test the solutions and choose the best solution for the design because doing so will help in improving it.

We must select the best solution among the suggested ones ..

Must minimize the risk to create the best design. Minimizing the risk by “Go Slow” Approach.

now all we have to do is to implement and achieve the solution we chosen; because it’s been the best solution for the best design.

Long Viewpoint will increase the cost. Will take a long time doing it. But: it will guarantee the best design. Improve the design.

Decreases the injuries in the design.

*The Management of ford decided not to take the long-term viewpoint and not to spent extra money on it. *They didn’t improve the design for the placement of the gas tank.

*They Faced Some Serious Problems and accidents. *People complained about the vehicles. *They Lost their reputation In the market.

It’s a method that helps engineers to analyze risk and determine whether a project should proceed or not.

Risk-Benefit Analysis is the comparison of the risk of a situation to its related benefits.

We accept a certain level of risk in our lives as necessary to achieve certain benefits.

*We assigned dollar amount for the risks and benefits. *then we select the most favorable ratio between risks and benefits.

And here we must consider that those who are taking the risks are also those who are benefiting. we can see that this task is difficult because sometimes it’s too hard to quantify and put a realistic price to the risks but still a useful technique.

There have been numerous studied of accidents and their causes with attempts to categorize them. Therefore understand the nature of accidents and find the ways to prevent them. In order to protect the safety of the public as the most important mission for engineers. They can be categorized in three types: procedural, engineered, and systemic [Langewiesche 1998].

The most common accidents.

Result of someone making a bad choice or not following established procedures. Amenable to be solved.

Example (in the airline industry) :

It happens due to the misreading of an important gauge. Flying when the weather should have dictated otherwise. Failure to follow regulations and procedures

Caused by flaws in the design such as:

- failures of materials - Devices that don’t perform as expected or don’t perform under all circumstances encountered. This accidents should be anticipated in the design stage and corrected during test.

Example (turbines)

microrocks sometimes develop in turbine blades in aircraft engines and when these microrocks become severe enough the blade can fail and break apart.

Hard to understand and hard to control.

Occurs in very complex technologies. Its difficult to be taken into during design, because there are many factors seeming insignificant come into the play.

Example (airline industry)

Modern aircraft are very complicated systems so that running them requires the work of many individuals. These individuals may commit mistakes, one mistake alone isn’t significant, but if several individuals committed a series of mistakes, this mistakes together may cause a major accident.

*The ford crown victoria police interceptor was introduced in 1979 and quickly became the best choice for law enforcement agencies throughout the US. *During the late 1990’s the crown victoria police interceptor (VI) made up about 85% of all law enforcement vehicles with over 400,000 units in service. *But after several well-publicized accident involving fires resulting from rear-end collisions, many police department halted the purchase of the VI.

*First, Ford adapted the Crown Victoria for use as a police vehicle and made some modification to make the vehicle suitable for police officers.

*But one aspect was not redesigned for police use !, which is the placement of the fuel tank.

*The fuel tank was located behind the rear axle, underneath the trunk, which was in a crush zone if the vehicle is hit from behind making it more susceptible to damage. *In addition, the orientation f the tank was in proximity to bolt that protruded from the axle and the suspension. In a collision the tank can be pushed into these bolts, resulting in piercing the tank and spilling gasoline on the ground, and the gasoline often ignites, engulfing the automobile in flames. *It should be noted here that this design met all federal safety standards.

*According to the national highway transportation safety istration (NHTSA), from 1991 to 2001, there were 16 police deaths that resulted from Crown Victoria catching fire after being struck from behind. *And there were more complains from different states like Florida, Arizona, etc. asking ford to look into the safety of the Crown Victoria. *In 2001, ford issued a technical service bulletin that suggested some retrofitting of the vehicles, including replacing a hexagonal-shaped bolt near the gas tank with a rounder, smoother one that would less likely to pierce the tank. *Ford did not notify law enforcement agencies of this bulletin, and also expected the local police agencies to pay for these changes.

In 2002, a police officer in Arizona was killed in a Crown Victoria after a fire caused by a rear-end crash. after this the state of Arizona canceled a $4 million order for more CVPIs. and as a result of the negative publicity , in 2002 ford announced that it would pay to install shields around the gas tanks and redesign the car. In 2003 ford announced plans to add a fire suppression system onto new cars. unfortunately, existing CVPIs could not be retrofitted with this safety system. In 2003, these problems culminated when the national association of police organization filled a lawsuit agains ford, in addition police departments in florida, ohio, texas, alabama and new jersey have filled a lawsuit agains ford. Since then ford has worked to make the CVPI safer and less susceptible to this type of accident.

It is clear that the design of the CVPI met federal standards, and it is also clear that more could have been done to ensure that the design of this vehicle was safe. Also should be noted here that ford has a history of problems associated with gas tank placement in its production. In the 1970s, the ford pinto, a compact car, also had problems with a gas tank.

The problems with the pinto are well documented and resulted in numerous lawsuits and huge problems for ford.`