Tools and Techniques of Quality Planning: 1. Quality Function Deployment (QFD) and the House of Quality 2. Failure Mode and Effect Analysis (FMEA)

1. Tools & Techniques of Quality
Planning
1
Nicola Mezzetti, Ph.D.
Department of Information Engineering and Computer Science University of Trento
e-mail: nicola.mezzetti@unitn.it

2. Quality Function Deployment

3. Definition
Quality Function Deployment (QFD) is a method for developing a design quality
aimed at satisfying the customer and then translating the customer’s demand into
design targets and major quality assurance points to be used throughout the
production phase.
• It is a structured approach to defining customer needs or requirements and
translating them into specific plans to produce products to meet those needs
• This understanding of customer needs is summarised in a product planning
matrix or “house of quality”.

4. The Purpose of QFD
• Plan new products.
• Design product requirements.
• Determine process characteristics.
• Control the manufacturing process.
• Document already existing product specifications.

5. History
• Developed by Yoji Akao in 1966.
• First implemented at Kobe Shipyard of Mitsubishi in 1972.
• First QFD training outside Japan at General Motors and Ford in 1972.
• By the late 1970’s most of the Japanese manufacturing industry were using QFD
(e.g., Toyota)
• In 1983, the first English QFD article was published.
• By late 1990’s DEC, AT&T, HP, IBM and Texas Instruments have published
information about QFD

6. The QFD Process
A five phases process that requires multiple functional disciplines to adequately
address the whole range of activities.
1. Capturing the Voice of the Customer
2. Product Planning
3. Product Design
4. Process Planning
5. Process Control
Each phase uses a matrix to translate higher level “what’s” in low level “how’s” -
product requirements or technical characteristics to satisfy these needs.
• Each phase, or matrix, represents a more specific aspect of 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

7. The Phases of QFD

8. Structure of the House of Quality

9. Capturing the Voice of the Customer
• Some products give little or no dissatisfaction; they do what the producer said
they would do. Yet, they are not scalable because some competing product has
features that provide greater customer satisfaction.
• The voice of the customer is the term to describe these stated and unstated
customer needs; it is captured in a variety of ways: direct discussions, interviews,
surveys, focus groups, customer specifications, observation, warranty data, field
reports, etc.
• Customer voices are diverse: there is no one unique and complete voice of the
customer; QFD requires that the basic customer needs are identified.
• The diverse voices must be considered, reconciled and balanced to develop a
truly successful product.

10. Capturing the Voice of the Customer
• Frequently, customers will try to express their needs in terms of "how" the need
can be satisfied and not in terms of "what" the need is.
• This limits consideration of development alternatives.
• In addition to "stated" or "spoken" customer needs, "unstated" or "unspoken" needs
or opportunities should be identified.
• Development and marketing personnel should break down general requirements
into more specific requirements by probing what is needed.
• Ask “why” until they truly understand what the root need is.
• Once customer needs are gathered, they have to be organised: the collected
information needs to be distilled into statements that express key customer
needs.
• Affinity diagramming is a useful tool to assist with this effort.

11. Product Planning
1. Customer needs or requirements are
stated on the left side of the matrix.
• If the number of needs or requirements
exceed twenty, decompose the matrix into
smaller subsystems.
• For each need or requirement, state the
customer priority using a 1 to 5 rating
2. Evaluate prior generation products
against competitive products.
• Based on this, develop a product strategy.
• Identify opportunities for breakthrough’s to
exceed competitor’s capabilities, area for
improvement to equal competitors
capabilities and areas where no
improvement will be made

12. Product Planning
3. Establish product requirements or
technical characteristics to respond
to customer needs:
• Characteristics should be meaningful,
measurable, and global.
• Characteristics should be stated in a
way to avoid implying a particular
technical solution.
4. Develop relationships between
customer requirements and product
requirements or technical characteristics.
• Use symbols for strong, medium and
weak relationships.
• Have all customer needs or
requirements being addressed?

13. Product Planning
5. Develop a technical evaluation of
prior generation products and
competitive products:
• Perform this evaluation based on the
defined product requirements or
technical characteristics.
6. Develop target values for product
requirements or technical
characteristics.
7. Determine potential positive and
negative interactions between
product requirements or technical
characteristics.
• Focus on negative interactions.

14. Product Planning
8. Calculate importance ratings:
• assign a weighting factor to relationship
symbols (e.g., 9-3-1)
• multiply the customer importance rating
by weighting factor in each box of the
matrix and add the resulting products in
each column.
9. Develop a difficulty rating (e.g., 1 to
5, 5 being very difficult and risky) for
each product requirement or technical
characteristic
10. Analyse the matrix and finalise the
product development strategy and
product plans. Finalise target values.

15. Product Planning

16. Product Design Process

17. Product Design Process
Once the product planning is complete, a more complete specification (the Product
Design) may be prepared.
1. The product requirements or technical characteristics and the product
specification serve as basis for developing product concepts.
• Product benchmarking, brainstorming, and R&D are sources for new product
concepts.
2. Once concepts are developed, they are analysed and evaluated.
• The Concept Selection Matrix may be used to help with this evaluation
process.

18. The Concept Selection Matrix
A. Product concepts are listed.
B. The various concepts are
evaluated on how well they satisfy
each criteria in the left column,
using the QFD symbols.
C. The symbol weights (strong=5,
moderate=3 or weak=1) are
multiplied by the importance rating
of each criteria.
D. These weighted factors are then
added for each column.
E. The preferred concept will have the
highest total.

19. Product Design Process (cont.)
3. A product concept is thus selected
A. The product concept is represented with block diagrams or design layout.
B. Critical subsystems, modules or parts are identified from the layout.
• Criticality is determined in terms of effect on performance, reliability, and
quality.
• Techniques such as fault tree analysis or Failure Modes and Effect Analysis
(FMEA) can be used to determine criticality from a reliability or quality
perspective.
C. The subsystem, assembly, or part deployment matrix is then prepared.

20. Product Design Process (cont.)
4. The product requirements or technical characteristics defined in the
product planning matrix become the “what’s” that are listed down the left
side of the product design matrix (or deployment matrix) along with priorities
(based on the product planning matrix importance ratings) and target values.
5. The product requirements or technical characteristics are translated into
critical subsystems, assembly or parts as well as their features (from the
selected concept).
6. Relationships are established between product requirements or technical
characteristics and the critical subsystem, assembly or part
characteristics.
7. Importance rating are calculated and the target values for each critical
subsystem, assembly or part characteristics are established.

21. Product Design Matrix

22. Process Design Process
QFD continues this translation and
planning into the process design
phase.
1. A concept selection matrix
can be used to evaluate
d i ff e re n t m a n u f a c t u r i n g
process approaches and
select the preferred approach.
• The “how’s” from the higher level
matrix become the “what’s” which
are used to plan the process.
• C o m m u n i c a t i o n b e t w e e n
engineering and manufacturing is
crucial and tradeoff’s can be
made to achieve mutual goals.

23. Process Design Process
• More detailed planning related to
process control, quality contro, set-
up, equipment maintenance and
testing can be supported by
additional matrices.
• The result is that Manufacturing
f o c u s e s o n t h e c r i t i c a l
processes, dimensions and
characteristics that will have a
significant effect on producing a
product that meets customers
needs.
Process/Quality control Matrix
• The process steps developed in the process
planning matrix are used as the basis for
planning and defining specific process and
quality control steps in this matrix.

24. Remarks
• While the Quality Function Deployment matrices are a good communication tool
at each step in the process, the matrices are the means and not the end: the real
value is in the process of communicating and decision-making with QFD.
• This methodology helps development personnel understand essential
requirements, internal capabilities, and constraints and design the product so
that everything is in place to achieve the desired outcome - a satisfied customer.
• Quality Function Deployment helps development personnel maintain a correct
focus on true requirements and minimises misinterpreting customer needs. As a
result, QFD is an effective communications and a quality planning tool.

25. Remarks
• While the Quality Function Deployment matrices are a good communication tool
at each step in the process, the matrices are the means and not the end: the real
value is in the process of communicating and decision-making with QFD.
• QFD is oriented toward involving a team of people representing the various
functional departments that have involvement in product development:
marketing, design engineering, quality assurance, manufacturing engineering, test
engineering, finance, product support, etc.
• The active involvement of these departments can lead to balanced consideration of
the requirements, the “what's", at each stage of this translation process and provide
a mechanism to communicate hidden knowledge (knowledge that is known by one
individual or department but may not otherwise be communicated through the
organisation).

26. Fault Mode and Effect Analysis

27. The History of FMEA
• The first formal FMEAs were conducted in the aerospace industry in the mid
1960s, specifically looking at safety issues
• Before long, FMEAs became a key tool for improving safety, especially in the
chemical process industries
• FMEA techniques have been around for about 50 years now
• More widespread use thanks in large part to the U.S. automotive industry and its
QS-9000 supplier requirements
• Required suppliers to conduct product/design and process FMEAs in an effort
to eliminate potential failures

28. What is FMEA?
Failure Mode and Effect Analysis (FMEA) is an engineering analysis technique for
identifying all possible failures in a design, manufacturing or assembly process, or
product or service:
• Identify and fully understand potential failure modes, their causes and effects on
failure on the system or end users, for a given product or process
• Assess the risk associated with the identified failure modes, effects and causes,
and prioritise issues for corrective action
• Identify and carry out corrective actions to address the most serious concerns
• Consider changes to the product design or manufacturing process
• Improve test and verification plans
• Improve process control plans

29. What is FMEA?
Failure Mode and Effect Analysis (FMEA) is an engineering analysis technique for
identifying all possible failures in a design, manufacturing or assembly
process, or product or service:
• Done by a cross-functional team of subject matter experts
• That thoroughly analyses product designs or manufacturing processes early in
the product development process.
• Finds and corrects weaknesses before the product gets into the hands of the
customer.

30. FMEA’s Objectives
• To look for all the ways a process or product can fail
• Failures are not limited to problems with the product
• Because failures also can occur when the user makes a mistake, those types
of failures should be included in the FMEA
• Anything that can be done to assure the product works correctly, regardless of
how the user operates it, will move the product closer to 100% customer
satisfaction

31. Different Types of FMEA
• System: focuses on global system functions
• Software: focuses on software functions
• Design: focuses on components and subsystems
• Process: focuses on manufacturing and assembly processes
• Service: focuses on service functions

32. System FMEA
Analysis at the highest level of the whole system, made up of various
subsystems. The focus is on system-related deficiencies, usually including:
• System safety and system integration
• Interfaces between subsystems or with other systems
• Interactions between subsystems or with the surrounding environment
• Single-point failures
• Functions and relationships that are unique to the system as a whole (i.e., do
not exist at lower levels) and could cause the overall system not to work as
intended

33. Design FMEA
Analysis at the subsystem level, made up of various components. The focus is on
product design-related deficiencies, with emphasis on:
• Improving the design
• Ensuring product operation is safe and reliable during the useful life od the
equipment
• Interfaces between adjacent components

34. Process FMEA
Analysis at the manufacturing/assembly process level. The focus is on
manufacturing related deficiencies, with emphasis on:
• Improving the manufacturing process
• Ensuring the product is built to meet requirements in a safe manner, with
minimal downtime, scrap and rework
• Manufacturing and assembly operations, shipping, incoming parts,
transporting of materials, storage, conveyors, tool maintenance, and labelling

35. Product/Design vs. Service/Process
• Product/Design FMEA:
• The objective for a product or design FMEA is to uncover problems with
products that will result in safety hazards, product malfunctions, or a
shortened product life
• Product FMEAs can be conducted at different phases of a product life cycle or
on product that are already in production
• Service/Process FMEA
• Uncovers problems related to the delivery of services or the manufacture of
products

36. How does it Work?
An effective FMEA identifies corrective actions required to prevent failures from
reaching the customer and to assure the highest possible yield, quality, and reliability
• Often referred to as bottom-up approach as it functions by means of the identification of
a particular cause or failure mode within a system in a fashion that traces forward the
logical sequence of this condition through the system to the final effect
• The FMEA method standardises the failure analysis and prevention approach
establishing a common language that can be used both within and between companies

37. How does it Work?
An effective FMEA identifies corrective actions required to prevent failures from
reaching the customer and to assure the highest possible yield, quality, and reliability
• Using data and knowledge of the process or product, a Risk Priority Number (RPN) is
generated for each failure mode and effect
• The higher the risk number, the more serious the failure could be, and the more important it is
that this failure mode be addressed
• The RPN is determined by multiplying three factors:
• Severity: the consequence of the failure, should it occur
• Occurrence: the probability or frequency of the failure occurring
• Detection: the probability of the failure being detected before the impact of the effect is
realised
• The failure modes with the highest RPNs should be managed first
• Once corrective actions have been taken, a new RPN is determined

38. Severity
Severity is a ranking number associated with the
most serious effect for a given failure mode
• Based on the criteria from a severity scale.
• A relative ranking within the scope of the specific
FMEA.
• Determined without regard to the likelihood of
occurrence of detection.

39. Occurrence
Occurrence is a ranking number associated with
the likelihood that the failure mode and its
associated cause will be present in the item
being analysed
• Based on the criteria from the corresponding
occurrence scale
• Has a relative meaning rather than absolute
value, determined without regard to the severity
or likelihood of detection

40. Detection
Detection is a ranking number associated with
the likelihood of detection of the failure mode/
cause, according to defined criteria
• A relative ranking within the scope of the specific
FMEA
• Determined without regard to the severity or
likelihood of occurrence

41. Limitations of RPN
RPN is not a perfect representation of the risk associated with a failure mode
and associated cause.
• Subjective
• Not continuous
High severity must be considered regardless RPN value.

42. The 10 Steps to FMEA
1. Review the process/product requirements
2. Brainstorming potential failure modes
3. List potential effects of each failure mode
4. Assign a severity rating for each effect
5. Assign an occurrence rating for each failure mode
6. Assign detection rating for each failure mode and/or effects
7. Calculate the RPN
8. Prioritise the FMs for action
9. Take action to eliminate or reduce the high-risk FMs
10.Calculate the resulting RPN as the FMs are reduced or eliminated

43. FMEA Worksheet

44. Prioritising Failure Modes for Action
After having calculated the RPNs, the FMs can be prioritised by ranking them in
order from the highest risk priority number to the smallest. A Pareto diagram is
helpful to
• visualise differences between the various ratings
• set a cut-off RPN, in order to establish the set of unacceptable

45. When to Use FMEA?
• When a process, product or service is being designed or redesigned, after
Quality Function Deployment
• When an existing process, product or service is being applied in a new way
• Before developing control plans for a new or modified process
• When improvement goals are planned for an existing process, product or
service
• When analysing failures of an existing process, product or service
• Periodically, through the life of a process, product or service

46. The Benefits of FMEA
• Reduces costs by identifying design and process improvements early in the
development process when relatively easy and inexpensive changes can be
made
• Improves product/process quality and reliability
• More robust process, and reduces or eliminates the trend for after-the-fact
corrective action and late changes crises
• Reduces potential costly liability when product or process do not perform as
promised
• Provides new ideas for improvement in similar designs or processes

47. FMEA Success Factors
Implementing the following actions will uniformly ensure FMEAs achieve safe,
reliable and efficient products and processes
1. Understanding the fundamentals and procedure of FMEAs
2. Preparation steps for each FMEA project
3. Applying lessons leaned and quality objectives
4. Providing excellent facilitation
5. Implementing an effective company-wide FMEA process

48. Preparation Steps
1. Determine the scope of the FMEA project
2. Make the scope visible and get consensus on boundaries
3. Assemble the right FMEA team
4. Establish ground rules and assumptions
5. Gather information
6. Prepare for the FMEA meetings

49. Applying Lessons Learned & Quality Objectives
Based on the experience certain common mistakes show up repeatedly:
• What are the primary ways that FMEAs can be done wrongly (mistakes made)?
• What are the leading factors that make for effective FMEAs (quality objectives)?

50. FMEA Facilitation
To be successful, FMEA leaders need to develop expert facilitation skills:
• Brainstorming
• Encouraging participation
• Active listening
• Controlling discussion
• Making decisions
• Conflict management
• Managing level of detail
• Managing time
• Unleashing team creativity

51. Effective Company-wide FMEA
A company-wide FMEA process is the entire set of systems and tasks essential to
support development of high-reliability products and processes through timely
accomplishment of well-done FMEAs.
• Management support for strategy and resources
• Roles and responsibilities
• Management review of high risk issues
• FMEA quality audits
• Execution of FMEA recommended actions
• Feedback look to incorporate lessons learned