V2.3 - Quality Function Deployment

• A system to translate customer requirements (CRs) into appropriate company requirements and technical features at every stage, from research through design, manufacturing, distribution, marketing sales and service

• Basic Idea => collecting and trying to satisfy customer’s needs

• But => Todaya highly-sophisticated industry requires a strong communication between specialists of different functions

• 1) Product Planning Matrix

  • Input => Customer requirements

  • Output => Critical Prduct Requirements

• 2) Part / Subsystem Deployment Matrix

  • Input => Critical Prduct Requirements

  • Output => Critical Components characteristics

• 3) Process Planning Matrix

  • Input => Critical Components characteristics

  • Output => Critical Process Steps

• 4) Process / Quality Control Matrix

  • Input => Critical Process Steps

  • Output => Process & Quality Control Parameters

• 1) Product Planning Matrix

  • Input => Customer requirements

  • Output => Critical Prduct Requirements

• 2) Part / Subsystem Deployment Matrix

  • Input => Critical Prduct Requirements

  • Output => Critical Components characteristics

• 3) Process Planning Matrix

  • Input => Critical Components characteristics

  • Output => Critical Process Steps

• 4) Process / Quality Control Matrix

  • Input => Critical Process Steps

  • Output => Process & Quality Control Parameters

• The HoQ is a matrix describing the transition/link from a set of customer requirements (i.e., the “WHATs”) to a set of technical solutions related to the product/service of interest, in order to met the customer requirements (i.e., the “HOWs”).

  
  

• Customer Requirements (CRs)

• Customer Requisites (Kundenwünsche)

• Customer Needs

• Customer Expectations

• Customer Desires

• Voice of the Customer (VoC)

  
  

• Technical Characteristics (TCs)

• Technical Solutions

• Product/Service Requirements

• Engineering Characteristics

• Voice of the Engineer (VoE)

  
  

  
  

• Cross-functional team of experts to develop an efficient QFD process.

• The QFD team includes the following functions

  • Marketing;

  • Design;

  • Quality;

  • Technology;

  • Production;

  • Logistics;

  • Suppliers.

• (1) Identifying customer requirements/needs

  • WHATs or CRs

• (2) Identifying product and engineering/technical design requirements/characteristics

  • HOWs or TCs (Tecnical characteristics)

• (3) Drawing up a relationship matrix;

• (4) Deploying the perceived quality (or CR) benchmarking;

• (5) Ranking/rating of the TCs (HOWs) and determining the technical (or TC) benchmarking;

• (6) Analysis of the correlations among the TCs (HoQ’s roof).

• (1) Identifying customer requirements/needs

  • WHATs or CRs

  • Customer Requirements

• (2) Identifying product and engineering/technical design requirements/characteristics

  • HOWs or TCs (Tecnical characteristics)

  • Product Engineering/Design Requirements

• (3) Drawing up a relationship matrix

  • Relationship matix

• (4) Deploying the perceived quality (or CR) benchmarking

  • Competetive Benchmarking Assessment

• (5) Ranking/rating of the TCs (HOWs) and determining the technical (or TC) benchmarking

  • Tecnical importance ranking

• (6) Analysis of the correlations among the TCs (HoQ’s roof)

  • Correlation Matrix

• Degree of Importance of Requirments

Customer requirements = Voice of the Customer (VoC)

• Personal interviews

  • researches showed that a sample of 20-30 respondents interviewed is enough for an exhaustive picture of CRs (VoC tends to be repetitive)

• Focus groups

  • 6 to 8 customers put together in a meeting lasting 2 hours (they stimulate each other)

• Qualitative techniques

  • the customers are requested to choose the products most similar and the ones most different

• Product analysis techniques

  • customers are requested to say how they buy, use, and evaluate a single product

• (1) Collection of the Voice of the Customer (VoC), in the form of initial CRs

• (2) Initial CRs should be translated, interpreted, specialized into a list of final CRs

  • Tool to derive the final CRs => Customer-Requirement Tree (CR tree).

    
    

• Intitial CR

• Intermediate CR

• Final CR

• CRs should be rational => it is important to remove redundant CRs or look for missing CRs.

• To improve the structuring/visualization of results, the final CRs can be grouped into macro-categories, depending on their affinity

  • Structural needs

  • Comfort and Ergonomics

  • Additional functionalities

  • Asthetics and Customization

The priority is decided on the basis of questionnaires submitted to a sample of (potential) respondents/customers.

→ Typically, the same sample of respondents involved in the VoC collection.

Customers are asked to rate the importance of CRs (or “degree of importance”) using a 5-level ordinal response scale:

1 = Very low importance,

2 = Low importance,

3 = Medium importance,

4 = High importance,

5 = Very high importance.

Importance judgments by respondents are aggregated through a central tendency indicator – i.e., median (𝑥 ̃) or mean value (𝑥 ̅) – and then included into the HoQ.

• Each CR should then translated into technical characteristics (TCs or technical solutions).

  • VoC (voice of the customer) → VoE (voice of the engineer).

• Each CR should be associated to one or more technical characteristics

  • “one to many” relationship.

• Technical characteristics should be:

  • clearly explained;

  • objective;

  • clearly/objectively measurable (suitable measuring procedure and unit);

  • related to a specific preference sense (↑ or ↓).

• Cross-functional QFD team has to determine the impact of the TCs on each CR.

• The relationship intensity is represented through the following symbols, in the so-called Relationship Matrix:

Two TCs are correlated if variations on the first one determine variations on the second and vice-versa.

The sign (+ or -) defines the direction of such a correlation (positive or negative/conflicting).

Identifying TC correlations can be useful for various reasons:

- Positive correlations can be due to redundancies and/or duplications of TCs.

- Negative correlations may characterize situations in which trade-off/compromise solutions are required.