Visit Six Sigma is a structured method for managing Quality which aims to reduce the variability (dispersion) of production processes in order to eliminate defects and non-conformities, and achieve a level of’Operational Excellence almost perfect.
In-depth definition : Developed by Motorola in the 1980s and popularized by General Electric, the Six Sigma method uses statistical tools to measure the quality of a product's performance. process capability to produce results within specification limits (tolerances defined in the Technical specifications). The aim of the Six Sigma is a maximum defect rate of 3.4 parts per million (PPM), which is equivalent to a level of Quality of 99.99966 %. The method is highly rigorous, based on factual and data-driven decision-making (the Big Data from measurement systems).
DMAIC Methodology (Problem Solving)
Six Sigma uses a five-phase roadmap called the DMAIC, for’Continuous Improvement (KAIZEN) existing processes. This cycle fits perfectly into the PDCA (Plan-Do-Check-Act) :
1. Define (D)
- Plan : Define the problem, the process involved and the project objectives (including the KPI to improve, such as the scrap rate or the TRS). Define the team (similar to D1 the’8D analysis).
2. Measure (M)
- Plan : Collect data on current performance (defect rate, variability). Calculate the initial sigma level of the process. This phase relies on the reliability of data collection (IoT, Machine Vision).
3. Analyze (A)
- Plan : Use statistical tools (such as the Ishikawa diagram, the Pareto method, and regression analyses) to identify the most important root causes (RCA) variability and defects. The aim is to prove statistically which input variables affect which output variables.
4. Innovate / Improve (I)
- Do : Develop, test and implement solutions to eliminate root causes and reduce variability (e.g., by implementing a "root cause analysis" system). Poka-Yoke or by modifying the Standardization of the process).
5. Control (C)
- Check/Act : Put in place mechanisms to maintain the gains achieved (new KPI, news Work Instructions). Ensure that the process remains stable at the new, improved sigma level (the Standardization and the sustainability of KAIZEN).
Six Sigma vs. Lean Management
Six Sigma is often associated with Lean Management to shape the approach Lean Six Sigma. Although both are aimed at the’Operational Excellence, their targets are different:
| Features | Six Sigma | Lean Management |
|---|---|---|
| Main objective | Reduce variability (improve Quality) | Reduce waste (Muda), improve speed and Pulled Flow |
| Key tool | Statistical tools (capability, regression) | Visual tools (VSM, Kanban, 5S) |
| Philosophy | Targeting precision | Targeting fluidity |
Visit Lean Six Sigma combines the strengths of both: Lean identifies and eliminates waste to speed up the flow, while Six Sigma ensures that this rapid flow produces an end result of the highest quality. Quality (flawless).
In conclusion, the Six Sigma is a rigorous, fact-based approach that enables companies to raise their level of Quality to a world-class standard, guaranteeing the reliability and cost-effectiveness of the Series Production reducing defects and non-quality costs to almost zero.
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