DFSS (Design for Six Sigma)

The DFSS process drastically changes the way organizations design their products, services, and processes. DFSS allows early prediction of overall design quality, including potential problems that may occur later. Subir Chowdhury (2000) claims that

DFSS is the proper methodology because that is what DFSS is designed to attack — new products, services, or processes. Six Sigma's DMAIC, on the other hand, focuses on improvement … of existing products and services. This also reinforces my earlier point that Six Sigma does not have to be a prerequisite for DFSS (p.23).

The DFSS process also places an emphasis on total quality and customer satisfaction in the early design phases, to effectively and greatly reduce the need for product changes and process improvements. Snee, Heorl, and Hall (2003) stated that many organizations have now adopted the General Electric developed DMADV roadmap of Define, Measure, Analyze, Design, and Verify. This author also accepted this model and determines that this systemic approach uses the tools identified as DFSS tools in the "Six Sigma DFSS and PFSS Tools Listing" section at the end of this book. By including Six Sigma tools early into the design process, the probability of product or process failure is sharply reduced. It promotes creativity and innovation with a definite outcome of products and services of superior design.

A brief description of the DMADV roadmap stages will help to illustrate some examples of the tools used:

Define:	Perhaps "Benchmarking" will give some direction to what needs to be done. Also, Voice of the Customer tools such as House of Quality (Quality Function Deployment), Customer-First-Questions, Customer Needs Table. Others are Gap Analysis, Problem Specification, Process Mapping, Problem Analysis, Value Analysis, Five Whys.
Measure:	Important tools are Data Collection Strategy, System Analysis (SIPOC), Measurement Matrix, Objectives Matrix (OMAX), Failure Mode and Effect Analysis (FMEA), Process Capability Ratios, Cost of Quality, Checksheet, Descriptive Statistics, Importance Weighting, Basili Data Collection Method, Balance Sheet.
Analyze:	Typically applied tools are Variance Analysis, Process Capability Ratios, Pareto Chart, Trend Line, Correlation/Regression, Process Analysis, Hypothesis Testing, most problem solving tools such as Five Whys, Problem Selection, Process Flowchart, Cause and Effect Diagram, Work Flow Analysis.
Design:	Tools that bring much to this stage are Design of Experiments (DOE) tools such as Analysis of Variance (ANOVA), Factor Analysis, Hypothesis Testing. Customer-First-Questions (Kano), Creativity Assessment, Forced Association, Semantic Intuition, Idea Borrowing, Phillips 66, Opportunity Analysis, Morphological Analysis, Checker-board Method, Circumrelation.
Verify:	Failure Mode and Effect Analysis (FMEA) results may provide a final check, Countermeasures Matrix, Yield Chart, Value Analysis, Point Scoring Evaluation, Customer Satisfaction Analysis, Measurement Matrix, Cost-Benefit Analysis.

The reader should refer to "Six Sigma DFSS and PFSS Tools Listing" in this book for a complete listing of tools that could effectively be applied in the DFSS phase (p.XX). Once the desired tools are identified, the reader should then find the flowchart containing the selected tools in the "Six Sigma Tools: Tools-Strings Examples" section, also in this book.