CED Unit II Part 1 [Compatibility Mode]

7/29/2019 CED Unit II Part 1 [Compatibility Mode]

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ED 9211 CONCEPTS OF ENGINEERING

DESIGN

UNIT II - CUSTOMER ORIENTED DESIGN &

SOCIETAL CONSIDERATIONS

Presented by

B.Stalin,M.E., (Ph.D).,Assistant Professor

Anna University : Chennai

Regional Centre, Madurai

UNIT II CUSTOMER ORIENTED DESIGN

& SOCIETAL CONSIDERATIONS

Identification of customer needs- customerrequirements- Quality Function Deployment-Product Design Specifications- Human Factors inDesign Ergonomics and Aesthetics. Societalconsideration - Contracts Product liability Protecting intellectual property Legal andEthical domains Codes of ethics Ethicalconflicts Environment responsible design-futuretrends in interaction of engineering with society.

TEXT BOOK:

George E. Dieter, Engineering Design - A Materials and Processing Approach,

McGraw Hill, International Editions, Si ngapore, 2000

OVERVIEW OF THE CONCEPTS OF ENGINEERING DESIGN

Identification of Customer Needs

Increasing worldwide competitiveness creates

a need for greater focus on the customers

wishes.

Engineers and businesspeople are seeking

answers to such questions as:

Who are my customers?

What does the customer want?

How can the product satisfy the customer whilegenerating a profit?


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Webster defines a customer as one that

purchases a product or service.

end user or external customer

Total quality management viewpoint, the

definition of customer can be broadened to

anyone who receives or uses what an

individual or organization provides.

Internalcustomer


Preliminary Research on Customers Needs

Brainstorming

Ideas for improvement were grouped into

common areas by using an affinity diagram


Gathering Information from Customers

Interviews with customers

Focus groups

Customer complaints

Warranty data

Customer surveys


Constructing a Survey Instrument

Determine the survey purpose

Determine the type of data-collection method to

be used

Identify what specific information is needed

Design the questions

Pilot lot the survey

Administer the survey


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Identification of Customer Needs Evaluating Customer Surveys

Focus musts and wants

Bar graph

Pareto diagram

Customer Requirements

Information gathered from customers and

research on products from market literature

and experimentation contributes to creating a

ranked listing of customer needs and wants.

These are the needs that form the end users

opinion about the quality of a Product.


From a global viewpoint, we should recognize thatthere is a hierarchy of human needs that motivateindividuals in general. Physiological needs such as thirst, hunger, sex, sleep,

shelter, and exercise. These constitute the basic needs ofthe body, and until they are satisfied, they remain theprime influence on the individuals behavior.

Safety and security needs, which include protection againstdanger, deprivation, and threat. When the bodily needsare satisfied, the safety and security needs becomedominant.

Social needs for love and esteem by others. These needsinclude belonging to groups, group identity, and socialacceptance.

Customer Requirements Psychological needsfor self-esteem and self-respect

and for accomplishment and recognition.

Self-fulfillment needsfor the realization of ones fullpotential through self development, creativity, andself-expression.


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Differing Views of Customer Requirements

From a design team point of view, the customer

requirements fit into a broader picture of the PDP

requirements, which include product performance,

time to market, cost, and quality.

Garvin identified the eight basic dimensions of

quality for a manufacturedproduct.

Performance: The primary operating characteristics of a

product. This dimension of quality can be expressed in

measurable quantities, and therefore can be ranked

objectively.

Customer Requ rements Features: Those characteristics that supplement aproducts basic functions. Features are frequently used to

customize or personalize a product to the customers

taste.

Reliability: The probability of a product failing or

malfunctioning within a specified time period.

Durability: A measure of theamount of use one gets from

a product before it breaks down and replacement is

preferable to continuedrepair. Durabilityis a measureof

product life. Durabilityand reliabilityare closely related.

Serviceability : Ease and time to repair after breakdown.

Other issues are courtesy and competence of repair

personnel and cost and ease of repair.

Conformance: The degree to which a products design

and operating characteristics meet both customer

expectations and established standards.


Aesthetics: How a product looks, feels, sounds, tastes,

and smells. The customerresponse in this dimension is

a matter of personal judgment and individual

preference.

Perceived quality: This dimension generally is

associated with reputation. Advertising helps to

develop this dimension of quality, but it is basically the

quality of similar products previously produced by the

manufacturer that influences reputation.

Classifying Customer Requirements A Kano diagram is a good tool to visually partition customer requirements

into categories that will allow for their prioritization. Kano recognized that

there are four levels of custom er requirements: (1) Expecters (2) Spokens

(3) Unspokens (4) Exciters

Expecters: These are the basic attributes that one would expect to see

in the product, i.e., standard features. Expecters are frequently easy to

measure and are used often in benchmarking.

Spokens: These are the specific features that customers say they want

in the product. Because the customer defines the product in terms of

these attributes, the designer must be willing to provide them to

satisfy the customer.

Unspokens: These are product attributes the customer does not

generally talk about, but they remain important to him or her. They

cannot be ignored. It takes great skill on the part of the design team toidentify the unspoken requirements.

Exciters: Often called delighters, these are product features that make

theproductunique and distinguish it from the competition.


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Customer Requirements Customer Requirements

Prioritized list of customer requirements Basic CRs that are discovered by studying competitor products during

benchmarking

Unspoken CRs that are observed by ethnographic observation

High-ranking customer requirements (CRs) found from the surveys

Exciter or Delighter CRs that the company is planning to address with

new technology.

The highest-ranked CRs are called critical to quality customer

requirements (CTQ CRs). The designation of CTQ CRs means

that these customer requirements will be the focus of design

team efforts because they will lead to the biggest payoff in

customersatisfaction.

Quality Function Deployment

Quality function deployment (QFD) is a planning and team

problem-solving tool that has been adopted by a wide variety

of companies as the tool of choice for focusing a design

teams attention on satisfying customer needs throughout the

product development process.

The term deployment in QFD refers to the fact that this

method determines the important set of requirements for

each phase of PDP planning and uses them to identify the set

oftechnical characteristics of each phase that most contribute

to satisfyingthe requirements.


QFD is a largely graphical method that aids a design team in

systematically identifying all of the elements that go into the

product development process and creating relationship

matrices between key parameters at each step of the process.

Gathering the information required for the QFD process forces

the design team to answer questions that might be glossed

over in a less rigorous methodology and to learn what it does

not know about the problem. Because it is a group decision-

making activity, it creates a high level of buy-in and group

understanding of the problem.

QFD, like brainstorming, is a tool for multiple stages of the

design process. In fact, it is a complete process that provides

input to guide the design team.


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The Development of QFD in Brief

QFD was developed in Japan in the early 1970s, with its first

large-scale application in the Kobe Shipyard of Mitsubishi Heavy

Industries. It was rapidly adopted by the Japanese automobile

industry. By the mid-1980s many U.S. auto, defense, and

electronic companies were using QFD. A recent survey of 150

U.S. companies showed that 71 percent of these have adopted

QFD since 1990. These companies reported that 83 percent

believed that using QFD had increased customer satisfaction

with their products, and 76 percent felt it facilitated rational

design decisions. It is important to remember these statistics

because using QFD requires a considerable commitment oftime

and effort. Most users of QFD report that the time spent in QFD

saves time later in design, especially in minimizing changescaused by poorly defining the originaldesign problem.



The product planning phase of QFD, called the

House of Quality, feeds results into the design

of individual parts, giving inputs into the

process planning design stage, which become

inputs into the production planning phase of

QFD.

QFD process is known as a methodology for

infusing the voice of the customer into everyaspect of the design process.

Quality Function Deployment The House of Quality translates customer requirements

into quantifiable design variables, called engineering

characteristics .

This mapping of customer wants to engineering

characteristics enables the remainder of the design process.

When the HOQ is constructed in its most comprehensive

configuration, the process will identify a set of essential

features and product performance measures that will be the

target values to be achieved by the design team. More

informationcan be interpreted from the House of Quality.

It can also be used to determine which engineering

characteristics should be treated as constraints for the design

process and which should become decision criteria forselectingthe best design concept.

QFDs House of Quality is a natural precursor to establishing

the product design specification.


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Quality Function Deployment Quality Function Deployment

Quality Function DeploymentQuality Function Deployment


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The House of Quality Configurations

Steps for Building a House of Quality

The Streamlined House of Quality

Room 1: Customer requirements

Room 2: Engineering characteristics

Room 4: The relationship matrix

Room 5: Importance Ranking

Absolute importance

Relative importance

Rank order


The Correlation Matrix or Roof of the House

of Quality

Room 3: The correlation matrix

Assessment of Competitors Products in

House of Quality

Room 7, Technical Assessment

Setting Target Values for Engineering

Characteristics

Room 8, Setting Target Values

Interpreting Results of HOQ

Product Design Specifications The goal ofdesign process planning is to identify, search, and

assemble enough information to decide whether the product

development venture is a good investment for the company,

and to decide what time to market and level ofresources are

required.

The resulting documentation is typically called a new product

marketing report. This report can range in size and scopefrom

a one-page memorandum describing a simple product change

to a business plan of several hundred pages. The marketing

report includes details on such things as the business

objectives, a product description and available technology

base, the competition, expected volume of sales, marketing

strategy, capital requirements, development cost and time,

expected profit over time, and return to the shareholders.

Product Design Specifications

In product development process, the results of the design planning

process that governs the engineering design tasks are compiled in the

form of a set of product design specifications (PDS). The PDS is the basic

control and reference document for the design and manufacture of the

product.

The PDS is a document that contains all of the facts related to the outcome

of the product development. It should avoid forcing the design direction

toward a particular concept and predicting the outcome, but it should also

contain the realistic constraints that are relevant to the design. Creating

the PDS finalizes the process of establishing the customer needs and

wants, prioritizing them, and beginning to cast them into a technical

framework so that design concepts can be established.

The process of group thinking and prioritizing that developed the HOQ

provides excellent input for writing the PDS. However, it must be

understood that the PDS is evolutionary and will change as the design

process proceeds.


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The beginning of the concept generation process, the PDS

should be as complete as possible about what the design

should do. However, it should say as little as possible about

how the requirements are to be met. Whenever possible the

specifications should be expressed in quantitative terms and

include all known ranges (or limits) within which acceptable

performance lies. For example: The power output of the

engine should be 5 hp, plus or minus 0.25 hp.

PDS is a dynamic document. While it is important to make it as

complete as possible at the outset of design, do not hesitate

to change it as you learnmore as the designevolves.


Product Design Specifications Product Design Specifications


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Product Design Specifications Product Design Specifications

Product Design SpecificationsHuman Factors in Design

Human factors is the study of the interaction between people, the products

and systems they use, and the environments in which they work and live.

This field also is described by the terms human factors engineering and

ergonomics.

Human factors design applies information about human characteristics to

the creation of objects, facilities, and environments that people use. It

considers the product as a human and machine system in which the

operator, the machine, and the environment in which it operates must all

function effectively.

Human factors goes beyond the issues of usability to consider design for

ease of maintenance and for safety. Human factors expertise is found in

industrial designers, who focus on ease of use of products, and in

industrial engineers, who focus on design of production systems for

productivity. We can relate the human interaction with a product to the

inputs used to describe the function structure of a design.


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Human Factors in Design

A person provides energy to the system by applying forces a nd torques

with human muscle power. People also provide signal information through

their senses of sight, hearing, touch, and to a limited degree, with taste

and smell. They provide material input when their body must be

contained by the product (the door must be large enough for the

shoulders of the body, or the light switch mus t be within reach).

Thus, it is important to understand more about human factors design to

achieve a harmonious interaction with human functions. Products that

rate high in human factors engineering are generally regarded as

high-quality products since they are perceived to work well by the user.

Table shows how various important product characteristics can be

achieved by focusing on key human factors characteristics.

Human Factors in Design

Human Factors in DesignHuman Physical Effort

The force that can be applied depends on the angle that the

elbow makes with the shoulder. This gets us into the topic of

biomechanics . The force that can be exerted also depends on

whether the person is seated, standing, or lying down. Thus,

the references noted here need to be consulted for data

referringto the specific typeof actionor motion.

Human muscle output is typically applied to a machine at a

control interface, like a brakepedal or a selector switch. These

control interfaces can take many forms handwheel, rotaryknob, thumbwheel, rollerball, lever, joystick, toggle switch,

rocker switch,pedal, handle, or slide.

Human Factors in Design Ergonomics


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It is particularly important to design the location of controls so

that bending and movements of the spine are not required,

particularly if these motions will be repetitive. This can lead to

cumulative trauma disorders, where stresses cause nerve and

other damage. Such situations will lead to operator fatigue

and errors.

Sensory Input

The human senses of sight, touch, hearing, taste, and smell

are chiefly used for purposes of controlling devices or

systems. They provide signals to the user of the design.


The human ear is effective over a frequency range from 20 to

20,000 Hz. Often hearing is the first sense that indicates there

may be trouble, as in the repetitive thumping of a flat tire or

the scraping sound of a worn brake. Typical auditory displays

that are used in devices are bells, beeps (to acknowledge an

action), buzzers, horns and sirens (to sound an alarm) and

electronicdevices to speak a few words.

The human body is especially sensitive to touch. With tactile

stimulation we can feel whether a surface is rough or smooth,

hot or cold, sharp or blunt. We also have a kinesthetic sense

that uses receptors to feel joint and muscle motion. This is an

abilitythat is highly developed in greatathletes.


User-Friendly Design

Design issues will create user-friendly designs:

Simplify tasks

Make the controls and their functions obvious

Make controls easy to use

Match the intentions of the human with the actions

required by the system

Use mapping

Displays should be clear, visible, large enough to read

easily, and consistent in direction Provide feedback

Utilize constraints to prevent incorrect action

Standardize

Human Factors in Design ErgonomicsHuman Factors in Design Ergonomics


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Reaction Time

The reaction time is the time to initiate a response when a

sensory signal has been received.

Anthropometric Data

Anthropometrics is the field of human factors that deals with

the measurements of the human body.

Design for Serviceability

Serviceability is concerned with the ease with which

maintenance canbe performed on a product

Many products require some form of maintenance or

Human Factors in Design Ergonomics Human Factors in Design Ergonomics


Service to keep them functioning properly. Products often

have parts that are subject to wear and that are expected to

be replaced at periodic intervals. There are two general

classes of maintenance. Preventive maintenance is routine

service required to prevent operating failures, such as

changingthe oil in your car.

Breakdown maintenance is the service that must take place

aftersome failureor decline in functionhas occurred.

Human Factors in Design Aesthetics


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