Quality Function Deployment
Quality Function Deployment :
The voice of the customer translated into the voice of the engineer.
To design a product well, a design teams
needs to know what it is they are designing, and what the end-users
will expect from it. Quality Function Deployment is a systematic
approach to design based on a close awareness of customer desires,
coupled with the integration of corporate functional groups. It consists
in translating customer desires (for example, the ease of writing for a
pen) into design characteristics (pen ink viscosity, pressure on
ball-point) for each stage of the product development. Quality function
deployment (QFD) is a tool that is sometimes referred to as the “voice
of the customer,” or as the “house of quality.” Quality function
deployment has been described as a process to ensure that the customers’
wants and, needs are heard and translated into technical
characteristics. The technical characteristics are handled by the
company through the design function, or better still, through a cross
functional team that includes sales, marketing, design engineering,
manufacturing engineering, and operations. This activity should focus
the product or service on satisfying customer requirements. QFD is a
tool for the entire organization to use. It is flexible and customized
for each case and works well for manufactured products and in the
service industry. The possible benefits for using the QFD process are:
- Creates a customer driven environment
- Reduces the cycle time for new products
- Uses concurrent engineering methods
- Reduces design to manufacture costs (fewer changes)
- Increases communications through cross functional teams
- Creates data for proper documentation of engineering knowledge
- Establishes priority requirements and improves quality
The goal of QFD is to translate often
subjective quality criteria into objective ones that can be quantified
and measured and which can then be used to design and manufacture the
product. It is a complimentary method for determining how and where
priorities are to be assigned in product development. The intent is to
employ objective procedures in increasing detail throughout the
development of the product. The 3 main goals in implementing QFD are:
- Prioritize spoken and unspoken customer wants and needs.
- Translate these needs into technical characteristics and specifications.
- Build and deliver a quality product or service by focusing everybody toward customer satisfaction.
QFD was first applied in the Kobe
shipyards in 1972 by Yoji Akao and his associates. It met with great
success and was introduced to the United States by Don Clausing in the
mid 1980s. Various United States companies (mostly automotive)
have applied the principles of QFD to their product design process.
By using QFD, Honda and Toyota were able to reduce the new product
cycle time to two and a half to three years The U.S. car makers were on a
cycle time of five years (late 80s to early 90s). QFD could be
described as a concurrent engineering tool. QFD provides a graphic
method of expressing relationships between customer wants and design
features. It is a matrix that lists the attributes a customer wants and
compares it to the design features (services that satisfy customer
wants). The collection of customer wants and expectations are expressed
through the methods available to most any organization: surveys, focus
groups, interviews, trade shows, hot lines, etc. The house of quality is
one technique to organize the data. The house of quality is so named
because of the image used in its construction. The use of matrices is
the key to the building of the house. The primary matrix is
the relationship matrix between the customer needs or wants and the
design features and requirements.
- The left side of the house has the customer needs
- The ceiling has the design features and technical requirements
- The right side contains the customer priorities (comparisons)
- The foundation contains the benchmarking, target values
- The roof of the house contains a matrix describing the relationship between design features
QFD uses some principles from Concurrent
Engineering in that cross-functional teams are involved in all phases
of product development. Each of the four phases in a QFD process uses
a matrix to translate customer requirements from initial planning stages
through production control. Each phase, or matrix, represents a more
specific aspect of the product’s requirements. Relationships between
elements are evaluated for each phase. Only the most important
aspects from each phase are deployed into the next matrix.
Phase 1, Product Planning:
Building the House of Quality. Led by
the marketing department, Phase 1, or product planning, is also called
The House of Quality. Many organizations only get through this phase of a
QFD process. Phase 1 documents customer requirements, warranty data,
competitive opportunities, product measurements, competing product
measures, and the technical ability of the organization to meet each
customer requirement. Getting good data from the customer in Phase 1 is
critical to the success of the entire QFD process.
Phase 2, Product Design:
This phase 2 is led by the engineering
department. Product design requires creativity and innovative team
ideas. Product concepts are created during this phase and part
specifications are documented. Parts that are determined to be most
important to meeting customer needs are then deployed into process
planning, or Phase 3.
Phase 3, Process Planning:
Process planning comes next and is led
by manufacturing engineering. During process planning, manufacturing
processes are flowcharted and process parameters (or target values) are
documented.
Phase 4, Process Control:
And finally, in production planning,
performance indicators are created to monitor the production process,
maintenance schedules, and skills training for operators. Also, in this
phase decisions are made as to which process poses the most risk and
controls are put in place to prevent failures. The quality assurance
department in concert with manufacturing leads Phase 4.
After setting the primary design
characteristics “hows” from the house of quality can be convert to as
the “whats” of another house that depicts detailed product design. This
process is repeated with a process planning house and then production
planning house. In this way, the voice of the customer is carried
through from design to manufacturing.
While it is easy to get caught up in the
process of constructing the house(s) and completing entry of the data,
one should not lose sight ofthe objectives of the house of quality
methodology. Hauser states that “The house of quality is a kind of
conceptual map that provides the means for interfunctional planning
and communications.” “The principal benefit of the house of quality is
quality in-house. It gets people thinking in the right directions and
thinking together.”
The voice of the customer, both external
and internal, is quantified and presented in the format of a house of
quality. The different organizational functional groups, engineering,
marketing, manufacturing and so on, are able to see the effect
ofdesign and planning changes in order to balance customer needs, costs
and engineering characteristics in the development of new or improved
products and services.
The House of Quality
The first phase in the implementation of the Quality Function Deployment process involves putting together a “House of Quality”
which is for the development of a climbing harness
which is for the development of a climbing harness
Steps to the House of Quality
Step 1: Customer Requirements – “Voice of the Customer”
The first step in a QFD project is to
determine what market segments will be analyzed during the process and
to identify who the customers are. The team then gathers information
from customers on the requirements they have for the product or service.
In order to organize and evaluate this data, the team uses simple
quality tools like Affinity Diagrams or Tree Diagrams.
Step 2: Regulatory Requirements
Not all product or service requirements
are known to the customer, so the team must document requirements that
are dictated by management or regulatory standards that the product must
adhere to.
Step 3: Customer Importance Ratings
On a scale from 1 – 5, customers then
rate the importance of each requirement. This number will be used later
in the relationship matrix.
Step 4: Customer Rating of the Competition
Understanding how customers rate the
competition can be a tremendous competitive advantage. In this step of
the QFD process, it is also a good idea to ask customers how your
product or service rates in relation to the competition. There is
remodeling that can take place in this part of the House of Quality.
Additional rooms that identify sales opportunities, goals for continuous
improvement, customer complaints, etc., can be added.
Step 5: Technical Descriptors – “Voice of the Engineer”
The technical descriptors are attributes
about the product or service that can be measured and benchmarked
against the competition. Technical descriptors may exist that
your organization is already using to determine product specification,
however new measurements can be created to ensure that your product is
meeting customer needs.
Step 6: Direction of Improvement
As the team defines the technical descriptors, a determination must be made as to the direction of movement for each descriptor.
Step 7: Relationship Matrix
The relationship matrix is where the
team determines the relationship between customer needs and the
company’s ability to meet those needs. The team asks the question, “what
is the strength of the relationship between the technical descriptors
and the customers needs?” Relationships can either be weak, moderate, or
strong and carry a numeric value of 1, 3 or 9.
Step 8: Organizational Difficulty
Rate the design attributes in terms of
organizational difficulty. It is very possible that some attributes are
in direct conflict. Increasing the number of sizes may be in
conflict with the companies stock holding policies, for example.
Step 9: Technical Analysis of Competitor Products
To better understand the competition,
engineering then conducts a comparison of competitor technical
descriptors. This process involves reverse engineering
competitor products to determine specific values for competitor
technical descriptors.
Step 10: Target Values for Technical Descriptors
At this stage in the process, the QFD
team begins to establish target values for each technical descriptor.
Target values represent “how much” for the technical descriptors, and
can then act as a base-line to compare against.
Step 11: Correlation Matrix
This room in the matrix is where the
term House of Quality comes from because it makes the matrix look like a
house with a roof. The correlation matrix is probably the least
used room in the House of Quality; however, this room is a big help to
the design engineers in the next phase of a comprehensive QFD project.
Team members must examine how each of the technical descriptors impact
each other. The team should document strong negative relationships
between technical descriptors and work to eliminate physical
contradictions.
Step 12: Absolute Importance
Finally, the team calculates the
absolute importance for each technical descriptor. This numerical
calculation is the product of the cell value and the customer importance
rating. Numbers are then added up in their respective columns to
determine the importance for each technical descriptor. Now you know
which technical aspects of your product matters the most to your
customer!
The Next stage
The above process is then repeated in a
slightly simplified way for the next three project phases. A simplified
matrix involving steps 1, 2, 3, 5, 6, 7, 9 & 11 above is
developed. The main difference with the subsequent phases however, is
that in Phase 2 the process becomes a translation of the voice of the
engineer in to the voice of the part design specifications. Then,
in phase 3, the part design specifications get translated into the voice
of manufacturing planning. And finally, in phase 4, the voice of
manufacturing is translated into the voice of production planning.
QFD is a systematic means of ensuring that customer requirements are accurately translated into relevant technical descriptors throughout each stage of product development. Therefore, meeting or exceeding customer demands means more than just maintaining or improving product performance. It means designing and manufacturing products that delight customers and fulfill their unarticulated desires. Companies growing into the 21st century will be enterprises that foster the needed innovation to create new markets.
QFD is a systematic means of ensuring that customer requirements are accurately translated into relevant technical descriptors throughout each stage of product development. Therefore, meeting or exceeding customer demands means more than just maintaining or improving product performance. It means designing and manufacturing products that delight customers and fulfill their unarticulated desires. Companies growing into the 21st century will be enterprises that foster the needed innovation to create new markets.
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