CHAPTER 04

PDODUCT DESIGN ERGONOMICS

4.1. INTRODUCTION

The word ergonomics comes from two Greek words:

• ERGO: meaning work

• NOMOS: meaning laws

Ergonomics is a science focused on the study of human fit, and decreased fatigue and discomfort

through product design. Ergonomics applied to office furniture design requires that we take into

consideration how the products we design fit the people that are using them. At work, at school, or at home,

when products fit the user, the result can be more comfort, higher productivity, and less stress. However in

the past designers relied on common sense when considering the needs of the people who would use and

operate the products and systems they designed. Ergonomics is a relatively new science and can be

described as 'The science of looking at how people relate to the products or systems that they use or come in

to contact with.' In simple terms ergonomics is about how to make people more efficient at what they do.

A good example of how a product is ergonomically designed is a mobile phone. The phone has

rounded edges to make it comfortable, the distance between the microphone and the speaker fits the distance

between the average adults ear and mouth and the buttons are well spaced and easy to use. Notice also that

the buttons use a bold typeface that is easy to read.

Ergonomics can be an integral part of design, manufacturing, and use. Knowing how the study of

anthropometry, posture, repetitive motion, and workspace design affects the user is critical to a better

understanding of ergonomics as they relate to end-user needs.

As well as trying to improve the design of new products and systems, ergonomics is also used to

improve the efficiency of existing ones. It is very important to ensure that people who spend a long time in

1

the same position do not develop painful and crippling problems such as repetitive strain injury (RSI).

Computer operators, for example sit for very long periods repeating very simple movements. One way of

solving the problem may be to design a better chair. Most chairs are like the ones you sit on at school, they

cannot be adjusted. We have to adjust ourselves to suit the chair which results in fidgeting, discomfort and

loss of attention. Ergonomic designers believe that adjustable chairs would be better. If the operators were

more comfortable, efficiency would be improved and there would be less chance of injury.

So, ergomonics is about making things the right shape, size and weight for humans. But what if the room

that you are working in is too hot or too cold? People work best at ‘room temperature’ which is about 20 0 C.

You cannot work efficiently if you are too hot or too cold. Ergomics also considers noise, vibration, light,

and smell. In fact if your senses are uncomfortable you will not work efficiently.

Take a look at the picture below. The person is sitting at a work desk that has been ergonomically designed.

The heating, lighting and noise are carefully controlled in offices so that people are comfortable and work at

their best. Offices are carefully designed so that people can work efficiently.

SOME OF THE MOST IMPORTANT PRINCIPLES OF ERGONOMICS

The designer should aim for sitting position of work when it is not possible due to nature of work

then only standing position should be considered

Any unnatural position of the body should be avoided for reduction of body fatigue

The working area should be properly designed both for sitting and standing postures of the body

The most frequent movement of the arms should be close to the body as possible so that a person can

use implements without stretching them

The system requiring the use of knobs, levers, hand grips and push buttons should be properly

designed and located for efficient control as they directly influence the efficiency of the operator.

Ergonomics can be split up in to three main areas:

1) Anthropometrics

The study of human measurements such as height, arm length, reaches, etc.

2) Physiology

The study of bodily strength, fatigue, reaction times etc.

3) Psychology

2

The study of behavior - especially the way we react to heat, light, texture, color, noise, etc.

These sciences are applied by the ergonomist towards two main objectives:

the most productive use of human capabilities and,

the maintenance of human health and well-being.

HISTORY OF ERGONOMICS

The foundations of the science of ergonomics appear to have been laid within the context of the

culture of Ancient Greece.

Evidence indicates that Hellenic civilization in the 5th century BC used ergonomic principles in the

design of their tools, jobs, and workplaces.

World War II marked the development of new and complex machines and weaponry, and these made

new demands on operators' cognition.

The decision-making, attention, situational awareness and hand-eye coordination of the machine's

operator became key in the success or failure of a task.

It was observed that a fully functional aircraft, flown by the best-trained pilots, still crashed.

In 1943, Alphonse Chapanis , a lieutenant in the U.S. Army, showed that this so-called "pilot error"

could be greatly reduced when more logical and differentiable controls replaced confusing designs in

airplane cockpits.

In 1949 a group of people decıded to form a socıety for ‘the study of human beıngs ın theır workıng

envıronment.

4.2. INTERACTION BETWEEN MEN AND MACHINE

Most machines work in coordination with people. Consider the types of interactions you have with a

standard gas-powered lawn mower. First, in starting and pushing the mower you occupy a work space

around the mower. You have to bend in this space to reach the starting of mechanism, then you have to

position yourself while holding your arms at a certain height to push and steer the mower. Second you

provide a source of power to the mower to start it and to push it. (Even if electrically started you have to

push a button or turn a key). Additionally, it takes muscle power to steer it, whether you are walking behind

or riding it. Third you act as a sensor, listening to determine if anything is stuck in the mower, and feeling

with your hands any feedback motion through seeing whether you are going so that you can steering that

might give you information on how well you are guiding the mower. Fourth, based on the information

received by the sensory inputs, you act as a controller. You determine how much power to provide and in

what direction the mower under control.3

These four ways a person interacts with the product: as occupant of work space, as power source, as sensor,

and as a controller - form the basis of the study of the human factors that play a major role in the design of a

device.

Beyond these four basic types of interactions between the product and person, there are further human

interactions issues that must be considered during design. First, even those devices that spend their operating

life remote from all human interaction, at the bottom of a well or in a deep space, must first be assembled.

The assembler must interface with the device in the same four ways as described in the lawn-mower

example. Second, most devices have to be maintained, which presents yet another situation for the

consideration of human interaction in the design of a product.

Human factors must be taken into account for every person who comes into contact with the product,

whether during manufacturing, operation, maintenance and repair or disposal.

Two reasons for this concern with human factors are quality and safety.

Products are perceived to work as they should if they are comfortable to use (there is a good match

between the device and the person in workspace), they are easy to use (minimal power required), their

operating conditions is easily sensed, and their control logic is natural, or used friendly. Of equal

importance is the concern for safety. Although not listed as one of the factors in the survey, it is readily

assumed that an unsafe design will never be perceived as quality product. Customers assume that neither

they nor others will be injured, and that no property will be destroyed (obvious exceptions are products that

are designed to destroy or injure)

In the following sections all the issues will be further explored, with emphasis on understanding the

interactions between humans and machines in order to ensure that quality and safety are designed into the

product.

4.3. ANTHROPOMETRICS

.

4

Anthropometry is the science that measures the range of body sizes in a population. It provides data

on dimensions of the human body in various postures. When designing products it is important to remember

that people come in many sizes and shapes. Anthropometric data varies considerably between regional

populations. For example, Scandinavian populations tend to be taller, while Asian and Italian populations

tend to be shorter.

The challenge for designers and engineers is to design things which can be used by the majority of

the population. Because we are all different this often means providing a limited form of adjustment. The

driver’s seat in a car has a number of adjustments which allow it to be customized by each driver. It is only

Formula One drivers who have cockpits tailor-made to their own measurements!

Knowing the measurements of the person or persons for whom you are designing is the key to

successful design. Anthropometrics is the study of facts and figures relating to the human body such as

height, arm length, weight, etc. Henry Dreyfus, an American industrial designer, pioneered the gathering

of this information; he called it human engineering. He was concerned about extreme dimensions as well as

the average ones, as people come in all shapes and sizes. In addition to producing charts of the average

anatomical sizes of all parts of the human body, he also gathered information on every conceivable aspect,

such as: the amount of pressure the average foot can comfortably exert on a pedal; how hard a hand can

effectively squeeze; the reach of an arm. All this information produces a very detailed picture of the average

man and woman.

However, anthropometric data differs between races, and changes with time. For example, some

Asian races were traditionally smaller than western races. British manufacturers exporting beds to Japan had

to make smaller beds than those sold in Europe. However with improved diet and an increased protein

intake, these races are quickly catching up. Most races are gradually getting bigger because of both better

diet and better health care. Look at the doorways in old houses - nowadays many people have to bend down

to get through them.

If a graph is plotted of the height of any population, it will look like the one shown below. This is

known as the normal distribution curve. The line through the middle of the graph is known as the 50th

percentile or means (average) value. If height were being measured, the 50th percentile would be the height

that occurred most often. People whose height falls on the 50th percentile line are often said to have average

height. People whose height falls on the 5th percentile can be said to be small people, while people whose

height falls on the 95th percentile can be said to be tall people.

Designers should ensure that their products will be able to be used by 5th to 95th percentile users. To

design for people who do not fall in to the 5 th to 95th range would be very impractical. The 1st to 5th are

people who are very small whilst the 95th to 100th are very tall.

When selecting optimum sizes it is a common mistake to always design for the average person. For

example, if a door were made on the basis of average height then all those people over 50% would bump

5

their heads on the top. Therefore we select data based on the height of the 95th percentile male. Do you

know why we choose male?

Use the following criteria to decide which percentile range to select data from.

For Clearance the height should be no less than the 95th percentile user i.e. the largest.

For Reach the height should be no more than that of the 5th percentile user i.e. the smallest.

For Postural situations we often have to consider the average or 50th percentile value because this

accommodates the most users.

Once the correct percentile range has been chosen the actual measurements can be found in a number of

ways. The simplest method is to look up anthropometric tables. These contain vast amounts of information

on human dimensions in the 5th, 50th and 95th percentiles for men and women. They also contain

anthropometric data on various age groups of children.

Another method is to take measurements from a sample population of users and use these people when

testing prototypes.

Before selecting anthropometric data you must consider how the product will be used so that you can

determine where sizes will be affected by the human body. e.g. if you were carrying something such as a

briefcase then the distance from your hand to the floor would be important. However if you were pulling

something behind you then your stride would have to be taken in to account so that the device does not catch

your heels.

A sketch such as the one shown below would be a helpful starting point. This shows an ergonomic and

indicates crucial measurements.

6

Before looking at the anthropometric tables, study your sketches and ask yourself the following questions:

(i) Are you looking for a clearance, reach or postural measurement?

(ii) Which percentile range will you be looking for? (5th, 50th or 95th)

(iii) Will you be looking for male or female measurements?

Percentile Humans

Anthropometric dimensions for each population are ranked by size and described as percentiles.

It is common practice to design for the 5th percentile (5th %) female to the 95th percentile (95th %) male.

The 5th% female value for a particular dimension (e.g. sitting height) usually represents the smallest

measurement for design in a population.

Conversely, a 95th% male value may represent the largest dimension for which one is designing.

7

The 5th% to 95th% range accommodates approximately 90% of the population.

To design for a larger portion of the population, one might use the range from the 1st% female to the 99th%

male.

Figure. The relative sizes of different percentile humans. Data is from Dreyfuss, Kroemer, and Woodson texts referenced at the end of this handbook.

ANTHROPOMETRIC DATABASES

Anthropometric datasets compare people of different ages and occupations. Data in anthropometric

databases may represent static dimensions, such as “lower leg length” or functional dimensions such as

“reach.”

Common office environment posture measurements. Values are in Table 1.

Measurement Letter Female Male

Standing Overhead Reach A 74.9” – 86.8” 81.2” – 93.7”Standing Height B 60.2” – 68.4” 64.8” – 73.5”Standing Eye Height C 56.9” – 65.0” 61.4” – 69.8”

8

Standing Forward Reach D 30.8” – 36.1” 33.8” – 39.5”Sitting Height E 31.3” – 35.8” 33.6” – 38.3”Sitting Eye Height F 42.6” – 48.8” 46.3” – 52.6”Sitting Knee Height G 19.8” – 23.2” 21.4” – 25.0”Seat Depth H 16.9” – 20.4” 17.7” – 21.1”

Table 1. Anthropometric measurements (including allowances for clothing) of small and large males and females, from BIFMA Ergonomics Guidelines, 2002. All measurements are in inches.

4.4. PHYISOLOGY

Physiology is the science of how living things work. This subject is of interest to designers so that they can

design products or systems within the limitations of the human body. It gives information about the

functioning of the human body.

a) Work physiology addresses the energy requirements of the body and sets standards for acceptable

physical workrate and workload, and for nutrition requirements.

b) Environmental physiology analyses the impact of physical working conditions – thermal, noise and

vibration, and lighting – and sets the optimum requirements for these.

A car braking system must be designed in such a way that any driver can easily exert a force on the pedal

and bring the car to rest. Thus information needs to be gathered on the strength of peoples’ legs and then

lever and hydraulic systems designed to suit such forces. The designer must also consider which part of the

body is most suited to performing a specific task. Legs are stronger than arms and are more suited to simple

repetitive tasks involving large forces such as applying the brakes. Hands and fingers are more nimble and

are better suited to finer controls such as a steering wheel or adjusting the volume on a radio.

The shape and size of hand - grips vary tremendously and depend on the tasks that they are used for. The

picture below shows two grips, one is for a gas cooker ring whilst the other is for adjusting the height of an

office chair. The cooker control has a smooth texture and no grip as it is easy to turn and is used for fine

adjustment however the chair adjuster has to be gripped firmly to enable the user to tighten it; therefore it

has been serrated to provide plenty of grips.

To input information into the product, there must be controls that readily interface with the human.

Following figure shows 18 common types of controls and their use characteristics; it also gives dimensional,

9

force, and recommended use information. Note that the rotary selector switch is recommended for more than

two positions and is rated between ‘acceptable’ and ‘recommended’ for precise adjustment. Thus the rotary

switch is a good choice for the time control of the dryer. Also, for rotary switches with diameters between

30 and 70 mm, the torque to rotate them should be in the range from 0.3 to 0.6 N.m. this is important

information when one is designing or selecting the timing switch mechanism.

10

11

Humans often have to supply some force to power a product or actuate its controls. Human force-generation

data are often included with anthropometric data. This information comes from the study of biomechanics

(the mechanics of human body). Listed in above figures is the average human strength for different body

positions. In the data for “arm force standing “we find that the average pushing force 40 inch off the ground

(the average height of the mower handle) is 73 lb, with a note that hand forces of greater that 30 to 40 lb are

fatiguing. Although only averages, these values do give some indication of the maximum forces that should

be used as design requirements. Biomechanics considers the operation of the muscles and limbs, and ensures

that working postures are beneficial, and that excessive forces are avoided.

4.5. PSYCHOLOGY

Psychology is the study of the mind and the way it works. Using your five senses you transmit

information from the world around you to your brain. The brain interprets this information and provokes a

reaction. For example, a sudden loud noise will prompt you to cover your ears with your hands.

12

All aspects of the environment affect the way you behave i.e. if it is sunny you may feel happy and if it is

cloudy you may feel sad. In the same way a bright room will heighten your senses whereas a dull room will

make you subdued. There are a variety of aspects of product design which will affect your behavior and

having an understanding of how the mind works is important when designing the human/product

interface.

Designers can improve the human/product interface by making a product easy to use. The user must be able

to easily sense important information be it through touch, sight or sound and then react accordingly. For

example the on/off button must be easy to find and symbols for each of the different functions of a product

should be easy to understand.

The shape of a product can also suggest its function and dictate the way in which used - this is called

product semantics. The picture below shows an inkjet printer. The position of the input and output trays,

combined with the rounded form, suggest the path of the paper through the printer.

The display of information especially in a plane cockpit or power station control room presents a challenge

for a designer. Displays showing rates of change such as speedometers can be either digital or analogue. A

digital display is better for accurate measurements when the rate of change is slow whereas an analogue

display is better for showing faster rates of change and giving an overall picture of what is happening. In

practice a combination of both is used.

Look at a typical car dashboard. Identify which displays are analogue and which are digital and try to

explain why they were chosen.

On complex control panels important information such as warnings have to be relayed quickly to the

operator and this is when more than one sense may have to be called on. For instance a flashing light may

not be enough to attract the pilot’s attention in the cockpit so a warning sound may also be necessary.

One recent development in microprocessor technology is the membrane switch panel. These are often

found on products used out of doors such as mobile phones and cash dispensers. One problem with such

panels is that the switches don't move so you are often unsure if you have pressed the button or not. The

solution is to use a bleep which sounds as you press the button thus confirming that it has been pressed. If

one sensation is reinforced by another then you feel as if you have more control over the product or system.

4.6. VISUAL DISPLAYS

13

In general, when designing controls for interface with humans, it is always best to simplify the structure of

the tasks required to operate the product. Recall the characteristics of the short-term memory of human

beings. We learnt there that humans can deal with only seven unrelated items at a time. Thus, it is important

not to expect the user of any product to remember more than four or five steps. One way to overcome the

need for numerous steps is to give the user mental aids. Office reproducing machines often have a clearly

numbers sequence (symbol display) marked on the parts to show how to clear a paper jam, for example.

In selecting the type of controller, it is important to make the actions required by the system match

the intentions of the human. An obvious example of mis-match would be to design the steering wheel of a

car so that it rotates clockwise for a left turn-opposite to the intention of the driver and inconsistent with the

effect on the system. This is an extreme example; the effect of controls is not always so obvious. It is

important to make sure that people can easily determine the relationship between the intention and the action

and the relationship between the action and the effect of the system.

A product must be designed so that when a person interacts with it, there is only one obviously

correct thing to do. If the action required is ambiguous, the person might or might not do the right thing. The

odds are that many people will not do what was wanted, will make an error, and, as a result, will have a low

opinion on the product.

14

4.7. CASE STUDIES

15

4.7.1. DESIGN OF CONTROL PANEL OF A CLOTH DRYER

Most interfaces between humans and machines require human sense the state of the device and based

on the data to control it. Thus products must be designed with importance features readily apparent, and they

must provide for easy control of these features.

Consider the control panel from the clothe dryer. The panel had three controls, each of which is

intended both to actuate two toggle switches. The top switch is a three-position switch that controls the

temperature setting to either “low”, “permanent press”, or “high”. The bottom switch is a two-position

switch that is automatically toggles to off at the end of the cycle or when the dryer door is opened. This

switch must be pushed to start the dryer. The dial on the right controls the time for either the no-heat cycle

(air dry) on the top half of the dial or the heated cycle on the bottom half.

The dryer controls must communicate two functions to the human: temperature setting and time.

Unfortunately, the temperature settings on this panel are hard to sense because the ‘temperature’ rocker

switch does not clearly indicate the status of the setting and the air-dry setting for temperature is on the dial

that can override the setting of the ‘temperature switch’. There are two communication problems in the time

setting also; the difference between the top half of the dial and the bottom half is not clear and the time scale

is the reverse of the traditional clockwise dial. The user must not only sense the time and temperature and

must regulate them through the control. Additionally, there must be a control to turn the dryer on. For this

dryer, the rocker switch does not appear to be the best choice for this function. Finally, the labeling is

confusing.

16

This control panel is typical of many that are seen every day. The used can figure out what to do and what

information is available, but it takes some conjecturing. The more guessing required to understand the

information and to control the action of the product; the lower perceives quality of the product. If the

controls and labeling were as unclear on a fire extinguisher, for example, it would be all but useless-and

therefore dangerous. There are many ways to communicate the status of a product to a human. Usually the

communication is visual; however, it can also be through tactile or audible signals. The basic types of visual

displays are shown in figure.

When choosing which of the displays to use, it is important to consider the type information that needs to be

communicated. Figure.6 relates five different types of information to the types of displays.

Comparing the clothes-dryer control panel of figure to the information of figure, the temperature control

require only discrete settings and the time control a continuous (but not accurate) value. Since toggle

switches are not very good at displaying information, the top switch of the panel of figure, should be

replaced by any of the displays recommended for discrete information. The use of the dial to communicate

time setting seems satisfactory.

An alternative design of the dryer control panel is shown in figure. The functions of the dryer have been

separated, with the temperature control on one rotary switch. The ‘start’ function, a discrete control action, is

now a button, and the timer switch has been given a single scale and made to rotate clockwise. Additionally,

the labeling is clear and the model number is displayed for easy reference in service calls. In addition, note

that for the rocker switch, no more than two positions are recommended. Thus the top switch on the dryer,

figure.4 is not a good choice for the temperature setting.

CHAPTER 05

HUMAN VALUES IN DESIGN

5.1. INTRODUCTION

17

Engineering is not only applying scientific laws and principles to technical problems. It is focused on

improving the lot of society, and as such, it brings engineers into the mainstream of business and industry.

Almost all entry-level engineers become involved, at least tangentially, with situations that call for some

understanding of the law and situations that call for ethical judgments. Therefore, this chapter presents a

brief overview of some legal and ethical issues in engineering, with topics as broad as law and ethics we can

only scratch the surface, so we have chosen to focus on those issues that are most pertinent to engineering

design.

The followings are examples of where a design engineer might be concerned with legal and ethical issues:

Preparing a contract to secure the services of a product data management firm

Reviewing a contract to determine whether a contractor who built an automated production facility

has satisfactorily fulfilled the terms of a contract.

Deciding whether it is legal and ethical to reverse engineer a product

Managing a design project to avoid the possibility of a product liability suit.

Protecting the intellectual property created as part of a new product development activity.

Deciding whether to take a job with a direct competitor that is bidding on a contract in the area

where you are not working.

5.2. CONTRACTS

A Contract is a promise by one person to another to do or not to do something. Only promises that the

law will enforce are contracts. The three elements of a contract are: offer + acceptance + consideration.

An offer is an expression made by one person that leads another person to reasonably expect that the

promisor wishes to create an agreement. The offer must be clear, definite, and specific, with no room for

serious misunderstanding. An acceptance of the offer is necessary to make a contract legally binding. Both

the offer and the acceptance must be voluntary acts. A contract cannot be forced on anyone, A contract is

not enforceable by laws unless it contains an agreement to exchange promises with value, the consideration.

For example, if A and B enter into a contract in which A promises to pay B 1000 dollars for modifying a

CAD software package, both the money and the service are considerations.

5.3. TYPES OF CONTRACTS

An express contract is the contract in which all of the terms are agrees upon and expressed in words,

either written or oral. An oral contract, once made, can be just as legal as a written contract, but it is much

more difficult to prove and enforce. Moreover, many states have statutes of fraud that requires writing for

certain contracts to be enforceable.

An implied contract is a contract in which the agreement between parties is enforced by the legal system

wholly or in part by their actions. For example, Jim goes to the local convenience store, where he has an

account. He picks up a Sunday New York times and holds it up so the clerk sees him take it and the clerk

18

nods in return as he leaves the store with the paper. Jim has made an implied contract to pay for the

newspaper.

A bilateral contract is a contract in which two parties have both made a promise to each other. A promise is

made in return for a promise. Each party is both a promisor and a promise.

A unilateral contract is one in which the promisor does not receive a promise as consideration for her

promise but instead agrees to pay if she receives an act or service. For example, Mrs. Jones says to John

smith, “I promise to pay you 100 dollars tomorrow if you will clean out my basement and garage today”.

John is immediately goes to work. This constitutes acceptance of the offer and creates a unilateral contract.

An Engineer will have to deal with contracts in a number of different situations. Contracts for the purpose or

sale of property are common. On taking a job you may be asked to sign a contract stating that all technical

ideas that you develop belong to the company, even those conceived will not in the job. These contracts are

often negotiable at the time of employment and are something to consider when you are looking for

employment. In technical dealings between companies, one of the parties may be asked to sign a

confidentiality agreement. This is a contract in which one of the parties agrees to not disclose, make use of,

or copy a design or product that the other party is about to disclose.

Types of contracts when there is more than one promisor or promisee

Types of contracts Numbers of parties Liability

Joint Two or more persons promise the

same performance as a single party

All promisors are liable for complete

fulfillment of the contract

Several Separate promises made by more than

one promisor

Each promisor is liable for his or her

individual promise

Joint and several Two or more parties make a joint

contract but also state that they are

individually liable for completion of

contract

All promisors face cumulative liability

5.4. GENERAL FORM CONTRACTS

In general, every business contract should contain the following information:

1. Introduction to the agreement. Includes title and date

2. Name and address of all parties. if one of the parties is a corporation, it should be so stated.

3. Complete details of the agreement. State all promises to be performed. Include such details as

specifications and expected outcomes. Give details on promises of payments, including amounts,

timing of payments, and interest.

4. Include supporting documents such as technical information, drawings, specifications, and

statements of any conditions on which the agreement depends.

5. Time and date of the start of the work and of excepted completion.

19

6. Terms of payment

7. Damages to be assessed in case of nonperformance. Statement of how disputes are to be arbitrated.

8. Other general provisions of the agreement

9. Final legal wordings. Signature of parties, witnesses, and notary public.

5.5. DISCHARGE AND BREACH OF CONTRACTS

A contract is said to be discharged when the agreement has been performed to the satisfaction of both

parties. The contracting parties can agree at any time that the contract has been discharged. It can be

discharged if it becomes impossible to perform due to circumstances outside the control of the contracting

parties. e.g., force majeure. However, extreme difficulty in executing the contract does not discharge it even

if it becomes more costly to carry out than originally anticipated.

A breach of contract occurs when one party fails to perform his or her part of the contract. A legal injury

is said to have occurred, and the injured party can sue in court for damages. General or compensatory

damages are awarded to make up for the damage that occurred. Special damages are awarded for the direct

financial loss due to the breach.

5.6. LIABILITY

Any party to a contract must be clear on the potential liability he or she is incurring. Liability means

being bound or obligated to pay damages or restitution. Two ways to incur liability are breaking a contract

or committing a tort, such as fraud or negligence.

A breach of contract refers to violating a contract’s promise. Failure to deliver details drawings of a nes

machine by the date specified in the contract is a breach of contract. It makes no difference whether this was

done intentionally or not.

Fraud is intentional deceitful action aimed at depriving another party of his or her rights or causing

injury in some respect. Examples would be doubling billing a client or falsely certifying that a component

has passed ASME pressure vessel code.

Negligence is failure to exercise proper care and provide expertise in accordance with the standards of

the profession that result in damage to property or injury to person. This is the most common way for an

engineer to incur liability to the public. For example, an engineer fails to include a major source of loading

in design calculations for a public product so that the design fails. Note that being honest and well-

intentioned does not absolve the engineer from a legal charge of negligence.

5.7. PRODUCT LIABILITY

Product liability refers to the legal actions by which an injured party seeks to recover damages for

personal injury or property loss from the producer or seller of a product. Product liability suits are pursued

under the laws of tort.

20

5.8. DESIGN ASPECTS OF PRODUCT LIABILITY

The following aspects of the design process should be emphasized to minimize potential problems from

product liability.

1. Take every precaution to assure that there is strict adherence to industry and government standards.

Conformance to standards does not relieve or protect the manufacturer from liability, but it certainly

lessens the possibility of product defects.

2. All products should be thoroughly tested before being released for sale. An attempt should be made

to identify the possible ways a product can become unsafe and tests should be devised to evaluate

those aspects of the design. When failure modes are discovered, the design should be modified to

remove the potential cause of failure.

3. The finest quality control techniques available will not absolve the manufacturer of a product

liability if in fact the product being marketed is defective. However, the strong emphasis on product

liability has placed renewed emphasis on quality engineering as a way to limit the incidence of

product liability.

4. Make a careful study of the relationships between your product and upstream and downstream

components. You are required to know how malfunctions upstream and downstream of your product

may cause failure to your product. You should warn users of any hazards of foreseeable misuses

based on these system relationships.

5. Documentation of the design, testing, and quality activities can be very important. If there is a

product recall, it is necessary to be able to pinpoint products by serial or lot numbers. If there is a

product reliability suit, the existence of good, complete records will help establish an atmosphere of

competent behavior. Documentation is the single most important factor in winning or losing a

product liability lawsuit.

6. The design of warning labels and users instruction manual should be an integral part of the design

process. The appropriate symbols, color, and size and the precise wording of the label must be

develops after joint meeting of the engineering, legal, marketing, and manufacturing staffs. Use

international warning symbols.

7. Create a means of incorporating legal developments in product liability into the design decision

process. It is particularly important to get legal advice from the product liability angle on innovative

and unfamiliar designs.

8. There should be a formal design review before the product is released for production.

5.9. PROTECTING INTELLECTUAL PRORERTY

The protection of intellectual property by legal means has become a topic of general interest and

international diplomatic negotiations. There are two conflicting motivations for this:

1. Creations of the mind are becoming more valuable in the information age, and

21

2. Modern information technology makes it easy to transfer and copy such information.

We saw that intellectual property is protected by patents, copyrights, trademarks, and trade secrets. These

entities fall within the area of property law, and as such they can be sold or leased just like other forms of

property.

The functional features of a design can be protected with utility patent. A utility patent protects not only the

specific embodiments of the idea shown in the patent application but functional equivalent as well. A well-

written patent is the best protection for a valuable data. If an idea is worth patenting, it is worth hiring an

experienced patent attorney to do the job well.

A different type of patent, the design patent, covers the ornamental aspects of a product such as its shape,

configuration, or surface decoration. Design patents are easier to obtain than utility patents, and they are

easier to enforce in court. If a competitive design has essentially the same overall appearance, then it is in

violation of your patent. A design patent can have only one claim, which is a serious disadvantage, because

it means that every unique aspect of a product’s design requires a separate patent. This can be expensive.

A copyright has only limited usefulness in protecting product designs. This form of intellectual property is

primarily intended to protect writing.

Trademarks are used to protect the names or symbols (logo) of products. A related from of protection is

known as trade dress. This consists of distinctive features of a product like its color, texture, size, or

configuration. Trademark and trade dress are intended to protect the public about the source of a product-

that is, to protect against cheap ‘ knock-offs’. Trademark protection is achieved by registration with the

patent and trademark office or by actual use of the trade mark in the market place such that it achieves

market recognition. Obviously, it is easier to defend against a competiting trademark if it is registered. A

registered trademark is issued for 20 years and can be renewed every 20 years as long as the product remains

in the market place.

An innovation becomes a trade secret when a company prefers to forgo legal protection for the intellectual

property. The reason for doing this is often a feeling that patents are difficult or costly to defend in the

particular area of technology, or an unwillingness to let the public know what the company is doing. If the

company takes active steps to protect the trade secret, then the courts will protect it as a form of intellectual

property. Process innovations are more often protected by trade secrets than product innovations. Companies

sometimes require nondisclosure agreements from their employees and may attempt to legally prevent an

employee who leaves their employ with sensitive trade knowledge from working for a competitors in order

to protect a trade knowledge from working for a competitor in order to protect a trade secret.

5.10. THE LEGAL AND ETHICAL DOMAINS

We move now from considerations of the law to a discussion of ethics, and how ethical issues affect

the practice of engineering design. Ethics is the principles of conduct that governs the behavior of an

individual or a profession. It provides the framework of the rules of behavior that are moral, fair, and proper

22

for a true professional. Ethical conduct is behavior desired by society and is above and beyond the minimum

standards of the law.

Quadrant 1, legal and ethical behavior, is where you should strive to operate at all times. Most design and

manufacturing activities fall within this quadrant. Indeed, a good case can be made that quality id dependent

on ethical behavior. ’Doing what is right in the first place and doing what is best for all involved, when done

at every level of the organization and in every work process, has proven to be the most efficient way of

conducting a business.

Quadrant 2, legal and unethical, is the concern of the rest of this chapter. The goal is to explain how to

identify unethical behavior and to learn what to do about it when it occurs. There is a feeling that unethical

behavior in the workplace is increasing because of increasing workplace pressures and changing societal

standards. Most corporations have adopted codes of ethics. Many have established an ethics office and

offering ethics training to their personnel. It is interesting that the prevailing view about ethics instruction

has changed substantially. Throughout most of the 20th century the common view about ethics was that you

either or when you are growing up, it was too late. This is changing today to a view that ethics is a teachable

subject that can be learnt by just about everyone.

Quadrant 3, illegal and unethical, is the sector where ‘go-to-jail’ cards are distributed. In general most

illegal activities are unethical.

Quadrant 4, illegal and ethical, is a relatively rare event. An example could be an engineer who had signed

a secret agreement with an employer, but then found that the employer has been engaged in producing a

product that was very hazardous to the general public. Unable to get attention focused on the problem within

the company, the engineer goes to the press to warn the people. The engineer has breached a contract, but in

what is believed to be a highly ethical cause. Such a person would be called a whistle blower.

5.11. CODE OF ETHICS

23

We start by making a distinction between morality and professional ethics. Morality refers to those

standards of conduct that apply to all individuals within society rather than only to members of a special

group. These are the standards that every rational person wants every other person to follow and include

standards such as the followings:

Respect the rights of others

Show fairness in your dealings with others

Be honest in all actions

Keep promises and contracts

Consider the welfare of others

Show compassion to others

Note that each of these standards of conduct is based on the italicized values.

5.12. PROFESSIONAL ETHICS

By professional ethics we mean those standards of conduct that every member of a profession expects every

other member to follow. These ethical standards apply to members of that group simply because they are

members of that professional group. Like morality, standards and ethical conduct are value-based. Some

values that are professional ethics include:

Honesty and truth

Honor- showing respect, integrity, and reputation for achievement

Knowledge- gained through education and experience

Efficiency- producing effectively with minimum of unnecessary effort

Diligence- persistent effort

Loyalty- allegiance to employer’s goals

Confidentiality- dependable in safeguarding information

Protecting public safety and health

Note that some of these values are directed toward the employer (eg: diligence), some toward the customer

(e.g: confidentiality), some towards the profession (e.g. honor).

TYPICAL ETHICAL QUESTIONS ASSOCIATED WITH PRODUCT DESIGN

STEPS IN PRODUCT DESIGN POSSIBLE ETHICAL QUESTIONS

Market study Is the study unbiased, or has it been embellished to attract investors or

management support?

Conceptual design Will the product be useful or will it be just a gimmick?

Embodiment design Does the design team have sufficient expertise to properly judge whether

computer programs are giving reliable results? Have any patents been

violated?

Detail design Has checking of results been done?

Manufacturing Is the workplace safe and free of environmental hazards? Is enough time

24

allowed to do quality work?

Product use Is the product is safe to use? Are users informed of possible hazards?

Retirement from service Has the design allowed for recycle or reuse?

CHAPTER 05

HUMAN VALUES IN DESIGN

5.1. INTRODUCTION

Engineering is not only applying scientific laws and principles to technical problems. It is focused on

improving the lot of society, and as such, it brings engineers into the mainstream of business and industry.

Almost all entry-level engineers become involved, at least tangentially, with situations that call for some

understanding of the law and situations that call for ethical judgments. Therefore, this chapter presents a

brief overview of some legal and ethical issues in engineering, with topics as broad as law and ethics we can

only scratch the surface, so we have chosen to focus on those issues that are most pertinent to engineering

design.

The followings are examples of where a design engineer might be concerned with legal and ethical issues:

Preparing a contract to secure the services of a product data management firm

Reviewing a contract to determine whether a contractor who built an automated production facility

has satisfactorily fulfilled the terms of a contract.

Deciding whether it is legal and ethical to reverse engineer a product

25

Managing a design project to avoid the possibility of a product liability suit.

Protecting the intellectual property created as part of a new product development activity.

Deciding whether to take a job with a direct competitor that is bidding on a contract in the area

where you are not working.

5.2. CONTRACTS

A Contract is a promise by one person to another to do or not to do something. Only promises that the

law will enforce are contracts. The three elements of a contract are: offer + acceptance + consideration.

An offer is an expression made by one person that leads another person to reasonably expect that the

promisor wishes to create an agreement. The offer must be clear, definite, and specific, with no room for

serious misunderstanding. An acceptance of the offer is necessary to make a contract legally binding. Both

the offer and the acceptance must be voluntary acts. A contract cannot be forced on anyone, A contract is

not enforceable by laws unless it contains an agreement to exchange promises with value, the consideration.

For example, if A and B enter into a contract in which A promises to pay B 1000 dollars for modifying a

CAD software package, both the money and the service are considerations.

5.3. TYPES OF CONTRACTS

An express contract is the contract in which all of the terms are agrees upon and expressed in words,

either written or oral. An oral contract, once made, can be just as legal as a written contract, but it is much

more difficult to prove and enforce. Moreover, many states have statutes of fraud that requires writing for

certain contracts to be enforceable.

An implied contract is a contract in which the agreement between parties is enforced by the legal system

wholly or in part by their actions. For example, Jim goes to the local convenience store, where he has an

account. He picks up a Sunday New York times and holds it up so the clerk sees him take it and the clerk

nods in return as he leaves the store with the paper. Jim has made an implied contract to pay for the

newspaper.

A bilateral contract is a contract in which two parties have both made a promise to each other. A promise is

made in return for a promise. Each party is both a promisor and a promise.

A unilateral contract is one in which the promisor does not receive a promise as consideration for her

promise but instead agrees to pay if she receives an act or service. For example, Mrs. Jones says to John

smith, “I promise to pay you 100 dollars tomorrow if you will clean out my basement and garage today”.

John is immediately goes to work. This constitutes acceptance of the offer and creates a unilateral contract.

An Engineer will have to deal with contracts in a number of different situations. Contracts for the purpose or

sale of property are common. On taking a job you may be asked to sign a contract stating that all technical

ideas that you develop belong to the company, even those conceived will not in the job. These contracts are

often negotiable at the time of employment and are something to consider when you are looking for

26

employment. In technical dealings between companies, one of the parties may be asked to sign a

confidentiality agreement. This is a contract in which one of the parties agrees to not disclose, make use of,

or copy a design or product that the other party is about to disclose.

Types of contracts when there is more than one promisor or promisee

Types of contracts Numbers of parties Liability

Joint Two or more persons promise the

same performance as a single party

All promisors are liable for complete

fulfillment of the contract

Several Separate promises made by more than

one promisor

Each promisor is liable for his or her

individual promise

Joint and several Two or more parties make a joint

contract but also state that they are

individually liable for completion of

contract

All promisors face cumulative liability

5.4. GENERAL FORM CONTRACTS

In general, every business contract should contain the following information:

10. Introduction to the agreement. Includes title and date

11. Name and address of all parties. if one of the parties is a corporation, it should be so stated.

12. Complete details of the agreement. State all promises to be performed. Include such details as

specifications and expected outcomes. Give details on promises of payments, including amounts,

timing of payments, and interest.

13. Include supporting documents such as technical information, drawings, specifications, and

statements of any conditions on which the agreement depends.

14. Time and date of the start of the work and of excepted completion.

15. Terms of payment

16. Damages to be assessed in case of nonperformance. Statement of how disputes are to be arbitrated.

17. Other general provisions of the agreement

18. Final legal wordings. Signature of parties, witnesses, and notary public.

5.5. DISCHARGE AND BREACH OF CONTRACTS

A contract is said to be discharged when the agreement has been performed to the satisfaction of both

parties. The contracting parties can agree at any time that the contract has been discharged. It can be

discharged if it becomes impossible to perform due to circumstances outside the control of the contracting

parties. e.g., force majeure. However, extreme difficulty in executing the contract does not discharge it even

if it becomes more costly to carry out than originally anticipated.

27

A breach of contract occurs when one party fails to perform his or her part of the contract. A legal injury

is said to have occurred, and the injured party can sue in court for damages. General or compensatory

damages are awarded to make up for the damage that occurred. Special damages are awarded for the direct

financial loss due to the breach.

5.6. LIABILITY

Any party to a contract must be clear on the potential liability he or she is incurring. Liability means

being bound or obligated to pay damages or restitution. Two ways to incur liability are breaking a contract

or committing a tort, such as fraud or negligence.

A breach of contract refers to violating a contract’s promise. Failure to deliver details drawings of a nes

machine by the date specified in the contract is a breach of contract. It makes no difference whether this was

done intentionally or not.

Fraud is intentional deceitful action aimed at depriving another party of his or her rights or causing

injury in some respect. Examples would be doubling billing a client or falsely certifying that a component

has passed ASME pressure vessel code.

Negligence is failure to exercise proper care and provide expertise in accordance with the standards of

the profession that result in damage to property or injury to person. This is the most common way for an

engineer to incur liability to the public. For example, an engineer fails to include a major source of loading

in design calculations for a public product so that the design fails. Note that being honest and well-

intentioned does not absolve the engineer from a legal charge of negligence.

5.7. PRODUCT LIABILITY

Product liability refers to the legal actions by which an injured party seeks to recover damages for

personal injury or property loss from the producer or seller of a product. Product liability suits are pursued

under the laws of tort.

5.8. DESIGN ASPECTS OF PRODUCT LIABILITY

The following aspects of the design process should be emphasized to minimize potential problems from

product liability.

9. Take every precaution to assure that there is strict adherence to industry and government standards.

Conformance to standards does not relieve or protect the manufacturer from liability, but it certainly

lessens the possibility of product defects.

10. All products should be thoroughly tested before being released for sale. An attempt should be made

to identify the possible ways a product can become unsafe and tests should be devised to evaluate

those aspects of the design. When failure modes are discovered, the design should be modified to

remove the potential cause of failure.

28

11. The finest quality control techniques available will not absolve the manufacturer of a product

liability if in fact the product being marketed is defective. However, the strong emphasis on product

liability has placed renewed emphasis on quality engineering as a way to limit the incidence of

product liability.

12. Make a careful study of the relationships between your product and upstream and downstream

components. You are required to know how malfunctions upstream and downstream of your product

may cause failure to your product. You should warn users of any hazards of foreseeable misuses

based on these system relationships.

13. Documentation of the design, testing, and quality activities can be very important. If there is a

product recall, it is necessary to be able to pinpoint products by serial or lot numbers. If there is a

product reliability suit, the existence of good, complete records will help establish an atmosphere of

competent behavior. Documentation is the single most important factor in winning or losing a

product liability lawsuit.

14. The design of warning labels and users instruction manual should be an integral part of the design

process. The appropriate symbols, color, and size and the precise wording of the label must be

develops after joint meeting of the engineering, legal, marketing, and manufacturing staffs. Use

international warning symbols.

15. Create a means of incorporating legal developments in product liability into the design decision

process. It is particularly important to get legal advice from the product liability angle on innovative

and unfamiliar designs.

16. There should be a formal design review before the product is released for production.

5.9. PROTECTING INTELLECTUAL PRORERTY

The protection of intellectual property by legal means has become a topic of general interest and

international diplomatic negotiations. There are two conflicting motivations for this:

3. Creations of the mind are becoming more valuable in the information age, and

4. Modern information technology makes it easy to transfer and copy such information.

We saw that intellectual property is protected by patents, copyrights, trademarks, and trade secrets. These

entities fall within the area of property law, and as such they can be sold or leased just like other forms of

property.

The functional features of a design can be protected with utility patent. A utility patent protects not only the

specific embodiments of the idea shown in the patent application but functional equivalent as well. A well-

written patent is the best protection for a valuable data. If an idea is worth patenting, it is worth hiring an

experienced patent attorney to do the job well.

A different type of patent, the design patent, covers the ornamental aspects of a product such as its shape,

configuration, or surface decoration. Design patents are easier to obtain than utility patents, and they are

29

easier to enforce in court. If a competitive design has essentially the same overall appearance, then it is in

violation of your patent. A design patent can have only one claim, which is a serious disadvantage, because

it means that every unique aspect of a product’s design requires a separate patent. This can be expensive.

A copyright has only limited usefulness in protecting product designs. This form of intellectual property is

primarily intended to protect writing.

Trademarks are used to protect the names or symbols (logo) of products. A related from of protection is

known as trade dress. This consists of distinctive features of a product like its color, texture, size, or

configuration. Trademark and trade dress are intended to protect the public about the source of a product-

that is, to protect against cheap ‘ knock-offs’. Trademark protection is achieved by registration with the

patent and trademark office or by actual use of the trade mark in the market place such that it achieves

market recognition. Obviously, it is easier to defend against a competiting trademark if it is registered. A

registered trademark is issued for 20 years and can be renewed every 20 years as long as the product remains

in the market place.

An innovation becomes a trade secret when a company prefers to forgo legal protection for the intellectual

property. The reason for doing this is often a feeling that patents are difficult or costly to defend in the

particular area of technology, or an unwillingness to let the public know what the company is doing. If the

company takes active steps to protect the trade secret, then the courts will protect it as a form of intellectual

property. Process innovations are more often protected by trade secrets than product innovations. Companies

sometimes require nondisclosure agreements from their employees and may attempt to legally prevent an

employee who leaves their employ with sensitive trade knowledge from working for a competitors in order

to protect a trade knowledge from working for a competitor in order to protect a trade secret.

5.10. THE LEGAL AND ETHICAL DOMAINS

We move now from considerations of the law to a discussion of ethics, and how ethical issues affect

the practice of engineering design. Ethics is the principles of conduct that governs the behavior of an

individual or a profession. It provides the framework of the rules of behavior that are moral, fair, and proper

for a true professional. Ethical conduct is behavior desired by society and is above and beyond the minimum

standards of the law.

30

Quadrant 1, legal and ethical behavior, is where you should strive to operate at all times. Most design and

manufacturing activities fall within this quadrant. Indeed, a good case can be made that quality id dependent

on ethical behavior. ’Doing what is right in the first place and doing what is best for all involved, when done

at every level of the organization and in every work process, has proven to be the most efficient way of

conducting a business.

Quadrant 2, legal and unethical, is the concern of the rest of this chapter. The goal is to explain how to

identify unethical behavior and to learn what to do about it when it occurs. There is a feeling that unethical

behavior in the workplace is increasing because of increasing workplace pressures and changing societal

standards. Most corporations have adopted codes of ethics. Many have established an ethics office and

offering ethics training to their personnel. It is interesting that the prevailing view about ethics instruction

has changed substantially. Throughout most of the 20th century the common view about ethics was that you

either or when you are growing up, it was too late. This is changing today to a view that ethics is a teachable

subject that can be learnt by just about everyone.

Quadrant 3, illegal and unethical, is the sector where ‘go-to-jail’ cards are distributed. In general most

illegal activities are unethical.

Quadrant 4, illegal and ethical, is a relatively rare event. An example could be an engineer who had signed

a secret agreement with an employer, but then found that the employer has been engaged in producing a

product that was very hazardous to the general public. Unable to get attention focused on the problem within

the company, the engineer goes to the press to warn the people. The engineer has breached a contract, but in

what is believed to be a highly ethical cause. Such a person would be called a whistle blower.

5.11. CODE OF ETHICS

We start by making a distinction between morality and professional ethics. Morality refers to those

standards of conduct that apply to all individuals within society rather than only to members of a special

31

group. These are the standards that every rational person wants every other person to follow and include

standards such as the followings:

Respect the rights of others

Show fairness in your dealings with others

Be honest in all actions

Keep promises and contracts

Consider the welfare of others

Show compassion to others

Note that each of these standards of conduct is based on the italicized values.

5.12. PROFESSIONAL ETHICS

By professional ethics we mean those standards of conduct that every member of a profession expects every

other member to follow. These ethical standards apply to members of that group simply because they are

members of that professional group. Like morality, standards and ethical conduct are value-based. Some

values that are professional ethics include:

Honesty and truth

Honor- showing respect, integrity, and reputation for achievement

Knowledge- gained through education and experience

Efficiency- producing effectively with minimum of unnecessary effort

Diligence- persistent effort

Loyalty- allegiance to employer’s goals

Confidentiality- dependable in safeguarding information

Protecting public safety and health

Note that some of these values are directed toward the employer (eg: diligence), some toward the customer

(e.g: confidentiality), some towards the profession (e.g. honor).

TYPICAL ETHICAL QUESTIONS ASSOCIATED WITH PRODUCT DESIGN

STEPS IN PRODUCT DESIGN POSSIBLE ETHICAL QUESTIONS

Market study Is the study unbiased, or has it been embellished to attract investors or

management support?

Conceptual design Will the product be useful or will it be just a gimmick?

Embodiment design Does the design team have sufficient expertise to properly judge whether

computer programs are giving reliable results? Have any patents been

violated?

Detail design Has checking of results been done?

Manufacturing Is the workplace safe and free of environmental hazards? Is enough time

allowed to do quality work?

Product use Is the product is safe to use? Are users informed of possible hazards?

32

Retirement from service Has the design allowed for recycle or reuse?

33