Page 450 - Design for Six Sigma a Roadmap for Product Development

410 Chapter Eleven

11.5 Quality Systems and Control Plans
Control plans are the means to sustain any DFSS project findings.
However, these plans are not effective if not implemented within a
comprehensive quality operating system. A solid quality system can
provide the means through which a DFSS project will sustain its long-
term gains. Quality system certifications are becoming a customer
requirement and a trend in many industries. The validate (V) phase of
the ICOV DFSS algorithm requires that a solid quality system be
employed in the DFSS project area.
The quality system objective is to achieve customer satisfaction by
preventing nonconformity at all stages from design through service. A
quality system is the Six Sigma–deploying company’s agreed-on method
of doing business. It is not to be confused with a set of documents that
are meant to satisfy an outside auditing organization (i.e., ISO900x). In
other words, a quality system represents the actions, not the written
words, of a company. The elements of an effective quality system include
quality mission statement, management reviews, company structure,
planning, design control, data control, purchasing quality-related func-
tions (e.g., supplier evaluation and incoming inspection), design product
and process structure for traceability, process control, preventive main-
tenance, process monitoring and operator training, capability studies,
measurement system analysis (MSA), audit functions, inspection and
testing, service, statistical analysis, and standards.
Specifics from QS9000 as they apply to the DFSS project are found
in QS9000 sec. 4.1.2.1: “define and document organizational freedom
and authority to”

1. Initiate action to prevent the occurrence of any nonconformities
relating to the product, process, and quality system.
2. Identify and record any problems relating to the product, process,
and quality system.
3. Initiate, recommend, or provide solutions through designated
channels.
4. Verify the implementation solutions.

11.5.1 Control methods
Automated or manual control methods are used for both design (service
or product) and design processes. Control methods include tolerancing,
errorproofing (poka-yoke), statistical process control (SPC)* charting

*Examples of SPC charting are X-bar and range (R) or X and moving range (MR)
charts (manual or automatic), p & np charts (manual or automatic), and c & u charts
(manual or automatic).