What is Design for Six Sigma (DFSS)

Design for Six Sigma (DFSS) uses the Six Sigma methodology to develop new products, services, or processes.
Six Sigma and Lean typically focus on improvement of existing products, services, or processes. DFSS is somewhat of a spinoff of the existing framework, which focuses on “the voice of the customer” in the development of “new” products, creation of services, or new processes.

Design for Six Sigma results in more efficiency, profitability, and higher customer satisfaction.  The main objective of DFSS is to “design it right the first time” to avoid redoing or redesign of what was developed. Many industries find DFSS a great match for marketing and product development.  DFSS reviews conceptual vulnerabilities and operational vulnerabilities while infusing quality design principles.

There are a number of defined quality concepts. Each company or business will determine what quality means to them as defined by their customers. It is important to understand what quality means to your organization, but more important to define what quality is to your customers. Your customers drive the requirements of your products, processes, and services.  We will look into specific quality measures and the details involved in obtaining them. Quality may be defined in many ways, but it is important to understand what quality is.

Everyone defines quality differently when they are the customer. What one person sees as a quality product, another may deem as unacceptable.  One factor businesses use is profitability – the measure of strong sales and overall low cost in the entire enterprise operation. Profitability is most often linked to high quality and reasonable price.

Here are some more common Quality Definitions:

• The ISO 8402-1986 standard defines quality as “the totality of features and characteristics of a product or service that bears its ability to satisfy stated or implied needs.” *Source International Standards Organization
• Quality: Do the right thing, and do things right all the time.”
• Quality: “An inherent or distinguishing characteristic, a degree or grade of excellence.”
• Quality: “The totality of characteristics of an entity that bear on its ability to satisfy stated and implied needs.”
• Quality: The ratio of performance to expectation.
  
  

What is your definition of Quality?

Let us take a further look at quality methods and some quality principles you will use and need to understand.
Quality has evolved over generations, but businesses realized the need for quality and reduction of variability after the industrial revolution. We will review the historical development of quality methods in this chronology.
Quality began with the individual craftsman. If you wanted to buy from a craftsman, you would select the product which in your mind had the best price and the features you desired. At that time, the quality of work was assured by the work of individual crafters as the sole person responsible for the entire product.

As the industrial revolution evolved, we saw the implementation of the assembly line and specialization of labor.
The production process became more productive, routine, and also more complicated. Quality could no longer be assured by one individual worker’s skill.  We saw an increase in the volume and number of parts in the production, which resulted in variation in assembly and variation in part quality. This became an issue and impediment in production. It was this production which led to the need for quality improvement.

Quality Concepts:

• Control charts: Graphs used to study how a process changes over time.
• Histogram: The most commonly used graph for showing frequency distributions (how often each different value in a set of data occurs).
• Pareto chart: Shows on a bar graph which factors are more significant.
• Scatter diagram: Graphs pairs of numerical data, one variable on each axis, to look for a relationship.
• Stratification: A technique that separates data gathered from a variety of sources so that patterns can be seen.