12.1 Glossary of Key Terms

Below is a glossary of essential terms and concepts used in Six Sigma, Lean, and process improvement methodologies. These terms help practitioners understand and apply Six Sigma principles effectively.

A - C

• Baseline: The initial measurement of a process used as a reference point for improvement.
• Critical-to-Quality (CTQ): Key measurable characteristics that define the quality of a product or process from a customer’s perspective.
• Control Chart: A statistical tool used to monitor process stability and variability over time.
• Cycle Time: The total time taken to complete one cycle of a process.

D - F

• Defect: Any instance where a product or service fails to meet customer expectations or specifications.
• Defects Per Million Opportunities (DPMO): A metric that quantifies defects in a process per million opportunities.
• DMAIC: A data-driven improvement cycle used in Six Sigma to improve processes (Define, Measure, Analyze, Improve, Control).
• DMADV: A Six Sigma methodology focused on creating new processes or products (Define, Measure, Analyze, Design, Verify).
• Fishbone Diagram (Ishikawa): A tool for identifying the root causes of a problem by categorizing potential factors.

G - K

• Green Belt: A Six Sigma certification level for practitioners who lead smaller projects and assist Black Belts.
• Kanban: A Lean tool for visualizing work and managing workflow to enhance process efficiency.
• Kaizen: A philosophy of continuous improvement focusing on small, incremental changes.
• KPI (Key Performance Indicator): A measurable value that indicates how effectively an individual, team, or process achieves a goal.

L - P

• Lean Six Sigma: A methodology combining Six Sigma’s focus on reducing variability with Lean’s emphasis on eliminating waste.
• Master Black Belt: The highest level of Six Sigma expertise, responsible for strategic implementation and mentoring other belts.
• Pareto Chart: A bar graph that identifies and prioritizes problems or causes using the 80/20 rule.
• Process Capability: A measure of a process’s ability to produce output within specified limits.
• Process Mapping: A visual representation of a process, showing its steps and flow to identify inefficiencies.

Q - S

• Quality Function Deployment (QFD): A method for translating customer requirements into product or service specifications.
• Root Cause Analysis (RCA): A technique for identifying the fundamental reason for a problem or defect.
• Sigma Level: A statistical measurement of process performance, indicating how many defects occur per million opportunities.
• SPC (Statistical Process Control): The use of statistical methods to monitor and control a process.
• Standard Deviation: A measure of the variation or dispersion in a set of data points.

T - Z

• Throughput: The amount of material or items passing through a system or process within a given time.
• Value Stream Mapping (VSM): A Lean tool for visualizing and optimizing the flow of materials and information in a process.
• Voice of the Customer (VOC): The expressed needs and preferences of customers, often gathered through surveys or feedback.
• Work-In-Progress (WIP): Items that are in production but not yet completed, used to monitor flow efficiency.
• Zero Defects: A quality goal aiming for flawless output with no defects or errors.

Conclusion

This glossary provides a foundational understanding of key terms in Six Sigma and Lean methodologies. Familiarity with these terms is essential for practitioners at all levels, enabling effective communication and successful implementation of process improvement initiatives.