How to Use Quality Function Deployment for Enhanced Product Design

To begin, let's define Quality Function Deployment (QFD) within Lean Six Sigma:

QFD was created in Japan by Yoji Akao around 1966 during his time at Mitsubishi. Subsequently, Toyota and other automobile manufacturers adopted the method. He characterized QFD as a

Method to transform qualitative user demands into quantitative parameters, to deploy the functions forming quality, and to deploy methods for achieving the design quality.

The quality function deployment methodology comprises a four-phase process that uses interconnected matrices to guide the product development cycle. This process starts by gathering the Voice of the Customer (VOC), establishing design requirements, and finally defining the process and product quality control criteria.

The four cascading matrices of QFD, often called the Houses, these matrices are:

1. Product Planning:

   The initial phase begins with gathering the VOC and converting your customers' desires and needs into detailed product and service requirements and specifications. This phase also includes a competitive analysis to assess how effectively your competitors meet your customers' wants and needs. The preliminary design concept is derived from these specific product and service performance requirements and specifications. This initial framework is the House Of Quality (HOQ), the cornerstone of your QFD process.

   

   Image source: https://asq.org/quality-resources/house-of-quality

2. Part Deployment:

   In this phase, we identify the assemblies, systems, sub-systems, and components that significantly influence fulfilling your product and service design requirements. The essential characteristics of the product and service are translated into critical characteristics or specifications for parts and assemblies, as well as steps in the service process. These requirements or specifications are then delineated for each pertinent functional area.

   
   

3. Product and Service Planning:

   The manufacturing and assembly processes are developed in this phase according to your product and component specifications. This progression has moved from customer requirements to product requirements to process requirements.

   
   

4. Process and Quality Control:

   Conducting a pilot is advisable before a complete product launch. Having identified the characteristics of the product and process, it is essential to ensure that sufficient process and product quality controls are developed and implemented. These controls can be validated during the pilot phase. Full-scale production should commence only once the process is under control, exhibiting common cause variation, and after completion of process capability studies.

Image source: https://asq.org/quality-resources/qfd-quality-function-deployment

What are the advantages of QFD?

1. A structured method for collecting feedback from your customers.

2. Compelled to concentrate your development efforts on your customer's needs and specific requirements.

3. Adhering to the discipline and structure of the QFD process reduces the risk of omissions or oversights during the development process.