3) Qfd

Quality Function Deployment (QFD)

Sasadhar Bera, IIM Ranchi

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Introduction Quality Function Deployment (QFD) is a customer driven approach which translates the customer needs (or voice of customer) into technical requirements such as design targets, manufacturing process parameters and major quality assurance points throughout the product/service development process. It also shows which design targets are more important to ensure customer satisfaction. It helps a company move towards proactive designing quality rather than traditional inspection of product quality.

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Introduction (Contd.) QFD was introduced by Yoji Akao in Japan in 1966 and successfully applied at the Mitsubishi Heavy Industries Kobe Shipyard in 1972.

In late eighties, many Japanese, American, and European companies have adopted QFD to develop their product/service. QFD uses a series of matrices, which look like "house" to deploy customer input throughout design, manufacturing, and service delivery. Affinity diagram, tree diagram, matrix diagram and matrix data analysis tools are used in QFD. 4 Sasadhar Bera, IIM Ranchi

Voice of Customer

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Voice of Customer A customer need is a description in customer's own words, about the benefit to be fulfilled by the product or service. The voice of the customer is a hierarchical set of "customer needs" where each need has a priority. Priority indicates importance of a need to the customer.

Developing product based on the voice of the customer becomes a key criterion in quality management.

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Voice of Customer (Contd.) The three steps in the measurement and analysis of voice of customer as input in QFD are: (1) Identifying customer needs, (2) Structuring customer needs, and (3) Setting priorities for customer needs. Identifying customer needs: It is primarily a qualitative research task. The three questions which we have heard most often are: (1) Do focus group identify more customer needs? (2) How many people (or groups) must be interviewed? and (3) How many team members should analyse the data? 7 Sasadhar Bera, IIM Ranchi

Voice of Customer (Contd.) Structuring customer needs: QFD structures the customer needs into a hierarchy of primary, secondary, and tertiary needs. Primary needs, also known as strategic needs, are the 5 to 10 top-level needs. Each primary need is elaborated into 3 to 10 secondary needs. The tertiary needs, also known as operational needs, provide detail so that engineering and R&D can develop engineering solutions that satisfy the secondary needs. Setting priorities for customer needs: Some needs have higher priorities for customers than other needs. The QFD team uses these priorities to make decisions which balance the cost of fulfilling a customer need. 8 Sasadhar Bera, IIM Ranchi

Four-Phase Model of QFD

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Four-Phase Model of QFD The Four-Phase Model divides a product development process into four phases or steps using four matrices.

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Four-Phase Model of QFD (Contd.) 1st Phase: House of Quality (HOQ) In the first phase, collected customer needs for the product (or voice of customer) called WHATs and then to transform these needs into technical requirements called HOWs. The first phase develop matrix based on customer requirements, importance rating of each requirement, competing product evaluation, technical ability to meet each requirement. The output of this phase is prioritized technical requirements.

This phase is so fundamental in product development that the corresponding QFD matrix is given a special name called the House Of Quality (HOQ). 11 Sasadhar Bera, IIM Ranchi

Four-Phase Model of QFD 2nd Phase: Parts Deployment The second phase transforms the prioritized technical requirements into part characteristics, called Part Deployment. Parts are considered to be most important to meeting customer needs. Parts Deployment requires creativity and innovative team ideas. Product concepts are created during this phase and parts specification are documented.

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Four-Phase Model of QFD 3rd Phase: Process Planning The third phase examines the relationship between part characteristics and manufacturing process. In process planning, flow charts are prepared for manufacturing processes and process parameters (or target values) are documented.

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Four-Phase Model of QFD 4th Phase: Production Planning In last phase, the right production and control plans are created to monitor the production process, maintenance schedules, and skills needed for operators. Also, in this phase, decisions are made on the most risky process and contingency plans are put in place to prevent failures.

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House of Quality

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House of Quality (HOQ) Structure of HOQ

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House of Quality (HOQ)

(Contd.)

In theory, the goal of a House-of-Quality is prioritised technical requirement and to specify target value for each of the technical requirements. The left wall of the HOQ includes the customer requirements or needs. The customer requirements contain the voice of the customer, or what the customer expects from the product.

On the right side of wall are the prioritized customer requirements, or planning matrix. Listed items are customer competitive evaluation, customer importance rating of requirements, target value, scale-up factor, and sales point. 17 Sasadhar Bera, IIM Ranchi

House of Quality (HOQ)

(Contd.)

The ceiling or second floor, of the house contains the technical requirements. Customer expectations (customer requirements) are translated into engineering characteristics (technical requirements). Consistency of the product is provided through engineering characteristics, design constraints, and parameters. The interior walls of the house are the relationships between customer requirements and technical requirements. The roof of the house is the inter-relationship between technical requirements. Trade-offs between similar and/or conflicting technical requirements are identified. The foundation of the house is the prioritized technical requirements. Items such as technical benchmarking, degree of technical difficulty, and target values are listed. 18 Sasadhar Bera, IIM Ranchi

Steps to Build House of Quality

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HOQ: Identifying Customer Needs Step1: Identifying customer needs (WHATs) The first step of HOQ is to identify the customers of the product. Customer should be identified according to the nature of product and users of the product. In this step, the essence of customer’s needs and expectations are collected. Available methods for collecting customer needs include email survey, focus groups, individual interview, listening and observing people’s comments in trade shows, customer feedback, complaints, warranty data, and sales records. An affinity diagram or tree diagram tool is used to organize and evaluate opinions, ideas and information. 20 Sasadhar Bera, IIM Ranchi

HOQ: Identifying Customer Needs (Contd.) This list of customer requirements is divided into a hierarchy of primary, secondary, and tertiary customer requirements. An example of customer needs of fried vegetable is as below: Primary Needs

Secondary Needs

Appropriate ingredient

Good taste Good smell Good colour

Good appearance Good shape

Tertiary Needs Not too salty Moderately spicy Appetizing Hot Fresh Sweet smell Not overcooked Normal colour Good looking plate Not too full Tasteful arrangement 21 Sasadhar Bera, IIM Ranchi

HOQ: Planning Matrix Step2: Planning matrix The following steps are followed to develop the planning matrix. Step2.a) Step2.b) Step2.c) Step2.d) Step2.e) Step2.f)

Customer competitive evaluation Relative ranking of the customer needs Target value Scale-up factor Sales point Final weight of WHATs

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HOQ: Technical Requirements Step3: Identifying technical requirements (HOWs) Technical requirements are design characteristics that describe in the language of the designer or engineer’s requirements. The product development team or technicians identify the technical requirements (HOWs) by brainstorming sessions. Sometimes HOWs can be generated from current product standard. Proper HOWs may be selected by creating a cause-andeffect diagram that ensures that the HOWs are the firstorder causes for the WHATs. An affinity diagram may also be used to organize the selected HOWs . 23 Sasadhar Bera, IIM Ranchi

HOQ: Technical Relationship Between WHATs and HOWs Step4: Technical relationship between WHATs and HOWs The relationship matrix of WHATs versus HOWs is a systematic means for identifying the degree of relationship between each WHAT and each HOW. The purpose of the relationship matrix is to show whether the final technical requirements adequately address customer requirements. This assessment is usually based on expert experience, customer responses, or controlled experiments and is a vital step in the HOQ process.

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HOQ: Inter-relationship Between HOWs Step5: Inter-relationship between HOWs

The roof of the house of quality, called the correlation matrix, is used to identify any inter-relationship between each of the technical requirements. The correlation matrix is a triangular table attached to the technical requirements. Different symbols are used to describe the strength of the interrelationships.

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HOQ: Prioritize Technical Requirements Step6: Prioritize technical requirements The following steps are followed to develop prioritized technical requirement. Step6.a) Step6.b) Step6.c) Step6.d)

Technical competitive evaluation Degree of technical difficulty Target value Final importance of HOWs

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HOQ: Prioritize Technical Requirements (Contd.) Step6a: Technical competitive evaluation The performance of company’s product and competitors’ similar products are evaluated on each technical requirement. The technical competitive evaluation is often useful in uncovering gaps in engineering judgment. The ranking scale is used in each HOW is same as used in customer competitive evaluation. Step6b: Degree of technical difficulty

The degree of technical difficulty determines the ability of the company to implement the HOWs. The development team could estimate the difficulty level to achieve it through engineering and cost analysis. 27 Sasadhar Bera, IIM Ranchi

HOQ: Prioritize Technical Requirements (Contd.) Step6c: Target values A target for a HOW represents a level of performance on the HOW is required for its product to be competitive in the relevant markets. The targets should also be set to be reachable according to the company’s technical resources and existing product strength and weakness. Step6d: Final importance of HOWs

1 n Final importance: a j   R ij ci d j i 1 Rij : Weight assigned to relationship matrix ci : Final weights of WHATs , i = 1, 2, . . ., n dj : Technical difficulty of HOWs , j = 1, 2, . . ., m 28 Sasadhar Bera, IIM Ranchi

Benefits and Issues of QFD

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Benefits of QFD Tangible benefits Intangible benefits Lower start-up cost and production Improves customer cycle. Reduction in design time and satisfaction design cost. Identify the areas to be acted upon Provides a basis of and simulate the new design ideas improvement planning Involvement of every functional Facilitates area such as marketing, multidisciplinary manufacturing, purchasing etc. teamwork

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Issues in QFD QFD can be used in many different areas of the business like planning, testing, engineering, manufacturing, distribution, marketing, and service. However, it must be understood that a large amount of effort can be required to perform a formal QFD evaluation. If the amount of work is thought to be excessive, the other tools are more applicable.

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