QUALITY FUNCTION DEPLOYMENT
 

                (QFD)

Definition

QFD is a cross-functional planning tool.

Enables organizations to prioritize customer demands, develop innovative responses which are reliable
and cost effective.

The primary focus is the customer demands.

QFD derives requirements, ranks them in terms of customer values and transfers them into engineering
specifications.

 It also identifies key system parameters to be optimized.

 QFD is a part of TQM.
 

Why QFD ?

"Do the right things right the first time at the right cost" (TQM ?)

How to identify and arrange many "right things" and then to prioritize and accomplish them is a major task.

QFD is a tool to organize the customers' needs and then translate them into design criteria.

The process is driven by the customer requirements.

These requirements will determine if new technologies are needed or simple improvements are possible
or a revolutionary concept is required.

Design systems

QFD enables the design phase to focus on the key customer requirements.
It expands the time to define a product but shortens the overall design time.

 
Purpose of QFD & Benefits

* Listening to voice of customer

* Improving horizontal communication

* Prioritizing improvements

* Targeting cost reduction

* Targeting reliability

* Orchestrating engineering breakthroughs
 

Background

QFD was created in 1972 by Y. Akao at Kobe Shipyards

Need: To ensure all government regulations, critical characteristics and customer requirements were addressed.

A Matrix relating these items to control factors of HOW, was developed.
The matrix also showed relative importance of each entry.
Important items are identified and prioritized.

 
By mid 1980's 30 QFD matrices were developed.

Extentions: Akao, Macabe, Clausing, Pugh, Sullivan;
 

Many Companies used QFD extensively, with great success in product development.

Lessons:

Each application of QFD is unique.

The quickest way to fail is to use someone else's approach.

Learn the basic principlas of QFD.

QFD needs to be tailored to specific needs.
 

Methodology

The basic tool of QFD is the "House of Quality" matrix.
 
 

WHAT: Represent customer desires, requirements (Adjective, noun). Voice of the customer

HOW: Quality characteristics (measurable attributes) for customer desires that can be controlled.
Voice of the engineer.

PRIORITIZED CR: Importance ratings and competitive asessments are developed

RELATIONSHIPS: Customer requirements are translated into design engineering terms.
Interactions between relationships are identified

HOW MUCH: Prioritized quality characteristics and settings for target values. Engineering requirements
that are most critical for success are identified

 
Analyzing and diagnosing the "House of Quality" Matrix:

1. Blank columns: Quality characteristics that do not strongly correlate to any customer need.

2. Blank rows: Customer demands that are not being addressed by a quality characteristic.

3. Conflicts: When conflicts and inconsistencies between design criteria exist, research is initiated,
DOE/Taguchi methods are utilized to optimize conflicting quality characteristics.

4. Communications: Quality characteristics that relate to many customer demands and regulatory reqs.

5. Opportunities: to incorporate existing highly rated features.

6.Deployment: Significant quality characteristics that need further analysis.

(Move to other phases/ martices)

At this point the foundation for all future matrices have been completed. The rest of the matrices
will develop quickly (Hopefully!).

There are four phases in a QFD process:

1. The organization:

Management selects the project, the appropriate interdepartmental team, Defines the focus
of the QFD study.

2. The descriptive phase:

The team defines the product from several different directions; customer demands, functions,
subsystems, reliability, cost.

3. The breakthrough phase:

The team selects areas for improvement .
Finds ways to make them better through new technology, new concepts, better reliability,
cost reduction, etc. Monitors the bottleneck engineering process.

4. The implementation phase:

The team defines the new product and how it will be manufactured and operated.
 

Implementing QFD for large systems

A1- House of Quality: Identify key customer demands, identify key items to measure and
control. Set preliminary targets.

A2- Function vs Quality characteristics: Identify missing functions and quality characteristics.
Better definition of functions and technical issues.

B1- Function vs Customer needs: Learn conflicts between functions and customer needs.
Identify areas of opportunity for breakthrough.(Voice of the engineer & voice of customer).
.
B3-Preliminary breakthrough targets: Analyze needed breakthroughs, DOE/Taguchi analysis,
set breakthrough targets.

C1- New technology vs. Systems: Identify potential new technology, select system
changes based on new technology.

C2-Systems vs. functions: Identify key systems based on voice of engineer (functions).

C3-Systems vs. quality characteristics: Identify key systems based on quality characteristics.

B2-Preliminary cost analysis: In light of key systems and potential new technology do preliminary
cost targets.

B1- Function vs Customer needs: Identify target functions for cost reduction.

C2-Systems vs. functions: Identify target systems for cost reduction.

 F1, F2, F3-Value Eng, Factor analysis, FEM: Develop engineering breakthroughs on systems
and cost using value engineering, factor analysis, finite element method and other tools.

B2-Cost analysis: Revise cost analysis, evaluate cost position based on engineering breakthroughs.

A1- Revise House of Quality: Revise targets based on cost and engineering breakthroughs,
evaluate the impact of new systems and new technology.
 

Source:

Better designs in Half the Time
Implementing QFD
Bob King, Third Edition