Design for Six Sigma
Design for Six Sigma ( DfSS ) is a quality management method for robust products and processes that are as error-free as possible.
DfSS is used to design or redesign a product, process or service. The expected process sigma level for a DfSS product or a corresponding process or service should be at least 4.5 sigma (corresponding to around 1 per thousand = 1 error per 1000 possibilities), but it can also be 6 sigma (3.4 Errors per million possibilities ) or even higher if necessary.
A product or service with such a low error rate presupposes that the expectations and needs that are decisive for the customer ( critical to quality , abbreviated to CTQ) must be fully understood before a product or service can be completed and introduced.
Core processes in DfSS
In contrast to the Six Sigma core process DMAIC , the phases or steps for DfSS core processes are not universally recognized or defined, since almost every company or training organization defines DfSS differently. One of the reasons for this is that a company often introduces DfSS in order to adapt its business, industry and culture. Sometimes a DfSS version is introduced by a consulting company to support staff deployment.
A popular DfSS method is the DMADV. The five phases of DMADV are defined as follows, similar to DMAIC:
- Define the project goals and customer requests (internal and external),
- Measuring and defining customer needs and specifications,
- Analyze the process options to meet customer needs,
- Design (detailed) the process to meet customer needs,
- Verify : Ensure design performance and ability to meet customer needs.
A variant of the DMADV methodology is DMADOV : Define, measure, analyze, design, optimize and test ( verify ). There are several other "types" of DfSS: DCCDI, IDOV, and DMEDI. DCCDI became known through Geoff Tennant and is defined as defining, customer concept (English customer concept ), design, introduction (English implement ). There are many similarities between these phases and those of DMADV.
- Define the project goals
- Customer customer analysis is carried out,
- Concept concept ideas are developed, checked and selected,
- Design is executed to meet customer and business specifications,
- Implement rollout is done to develop and commercialize the product / service.
IDOV is a well-known design method especially in the manufacturing sector . The abbreviation IDOV is derived from Identify, Design, Optimize and Validate.
- Identify determine the customer requirements and specifications ( english critical to quality , abbreviated CTQ)
- Design translates customer needs into functional needs and into alternative solutions. A selection process selects the list of solutions up to the "best" solution,
- Optimize uses statistical tools and models to predict or calculate performance and optimize design or performance,
- Validate Confirming means ensuring that the design that is being developed reaches the customer CTQs.
Because the cost of the DMAIC method is high, smaller businesses usually cannot benefit from Six Sigma. ICRA Generation III attempts to circumvent this problem. The main idea behind ICRA is to develop innovative ideas.
ICRA (Innovate, Configure, Realize, Attenuate) helps to think through open questions of all kinds.
- Meet innovative innovations for growth - by recognizing value needs and defining change options
- Configure goals - by measuring the current state and analyzing contributing influences on this state
- Realize Realize increase - by improving defined actions and controlled input variables
- Narrowing attenuate gaps - by standardizing success factors and integrating what has been learned from them
While ICRA is supposed to generate innovative ideas, DMAIC is better suited for robust implementation of the innovative ideas.
Tools in DfSS
In the DfSS, similar to the DMAIC project from Six Sigma, a wide variety of tools are used. These include tolerance analysis , tolerance design , House of Quality and Quality Function Deployment . DfSS also uses special design tools , CAD tools and simulations such as Monte Carlo simulation in conjunction with statistical and non-statistical calculation methods. A possible calculation method of a non-statistical nature that can be used, for example (in addition to static analysis ) for static problems, would be the finite element method .
- Jens-Peter Mollenhauer, Christian Staudter, Renata Meran, Alexis Hamalides, Olin Roenpage, Clemens von Hugo: Design for Six Sigma + Lean Toolset: Implementing innovations successfully . Ed .: Stephan Lunau. 1st edition. Springer, Berlin 2007, ISBN 978-3-540-69714-5 .
- Jürgen Gamweger, Oliver Jöbstl, Manfred Strohrmann, Wadym Suchowerskyi: Design for Six Sigma - developing customer- oriented products and processes without errors . 1st edition. Hanser, Munich 2009, ISBN 978-3-446-41454-9 .