Design Specifications and QFD

Establishing the Need

• Sources:– The market: what do customers want?– New technology:

• Creates a market• Risky and expensive• Can be financially rewarding

– Higher level system• Support for industries such as planes,

automobiles

Collecting Information

• Customer: Inside or outside of company– External

• Obsolescence of product

• Discover of new technology

• New market requirements

• Competitor superiority

– Internal• Excess capacity

• Drop in profitability

• New technology

• New production methods

Collecting Information

• Company: what are its objectives?– Wants to grow and increase market share– Wants flexibility in unstable market– Wants high profits– Life cycle of product– Enterprise potential and limitations

Collecting Information

• Laws and Regulations:– Environmental control– Safety regulations– Factory regulations– Standards, company and government

• Market– Demands– Potential for product– Competition

Questions

• What is the need or problem really about?

• What implicit wishes and expectations are involved?

• What paths are open for development?

Quality Function Deployment

• Developed in the mid-70’s– Method for developing specifications from

voice of customer– Gives interdisciplinary teams a map for

working together

• Toyota needed to improve rust record– Body durability broken into 53 items– Ran experiments on details of production,

temperature control, coating composition

Before and After QFDP

re-P

rod

uct

ion

and

Sta

rt-u

p C

ost

s at

T

oyo

ta B

ody

Sho

p

Jan. 1977Pre-QFD

Apr. 1984Post-QFD(39% of Pre-QFD Costs)

Source: “The House of Quality,” J. Hauser and D. Clausing,Harvard Business Review, May-June 1988, pp. 63-73.

QFD vs. no QFD

20-24months

14-17months

1-3months

Job #1 +3months

Design Changes

90% of changescomplete

With QFD

No QFD

Why Use QFD?

A recent survey of 150 US companies:

• 69% use QFD

• 71% began using it since 1990

• 83% felt that it improve customer satisfaction

• 76% felt it facilitated rational decision making

QFD

• Why use QFD?– Helps uncover new information– Can be applied to entire design problem or

portions of it– Focuses team on what need to be

designed, not how to design it– Helps overcome favoritism

Steps of QFD• Identify the customer

• Determine customer requirements

• State whether desires are demands or wishes, rank the wishes

• Competition benchmarking

• Translate customer desires into measureable engineering requirements

• Set targets for design: dates

QFD: Step by Step1. Who are the customers?

2. Determine customer requirements– Collection of information

• Specify information needed• Determine type of data collection• Determine content of questions• Design questions• Order questions• Take data• Reduce data

QFD: Step by Step

2. Determine customer requirementsDelighted

CustomerSatisfaction

Fully Implemented

Product Function

Absent

Disgusted

Excitement

Basic

Perform

ance

QFD: Step by Step

3. Determine relative importance of requirements

4. Identify and evaluate competition: How satisfied is the customer now?

5. Generate product specifications: how will customers’ requirements be met?

QFD: Step by Step

6. Translate into measureable engineering req’ts– If there is not measureable requirement,

then it is not well understood– Two solutions

• Break into finer parts• Repeat step three

7. Identify relationships between customer and engineering requirements.

8. Set targets for design: how much is good enough?

QFD: Step by Step

House of Quality

Whats vs. Hows

Hows

Hows vs. How Muches

Now vs. What

Howsvs.

Hows

Whats

HowMuches

Whovs.

Whats

Who Now