Lean Six Sigma Tools Cheat Sheet

DMAIC Cycle 

  • Define: State problem & goals 

  • Measure: Collect reliable data 

  • Analyze: Identify root causes 

  • Improve: Implement solutions 

  • Control: Sustain gains 

Customer & Process Understanding 

  • VOC (Voice of Customer): Capture needs via surveys, interviews, logs 

  • SIPOC: Map Suppliers → Inputs → Process → Outputs → Customers 

  • CTQ Tree: Translate customer wants into measurable requirements 

  • Process Mapping: Visualize workflow to spot waste 

  • Value Stream Mapping (VSM): Show cycle time, lead time, value-added vs NVA 

Root Cause & Prioritization 

  • Pareto Chart: Focus on vital few causes (80/20 rule) 

  • Fishbone Diagram: Categorize possible causes (Methods, Materials, Machines) 

  • 5 Whys: Drill down to true root cause 

Data & Analysis Tools 

  • Control Charts: Monitor process stability 

  • Histogram: Show data distribution & variation 

  • Scatter Plot: Reveal correlations between variables 

  • Hypothesis Testing: Confirm statistical significance 

  • Regression Analysis: Quantify relationships & predict outcomes 

  • DOE (Design of Experiments): Test multiple factors efficiently 

  • MSA (Measurement System Analysis): Validate accuracy & repeatability 

Sustaining Improvements 

  • Control Plan: Document how to maintain improvements 

  • SPC (Statistical Process Control): Use stats to monitor quality 

  • FMEA (Failure Modes & Effects Analysis): Anticipate failures & mitigate risks 

✅ Quick Tip: Use DMAIC as your backbone, then plug in the right tool depending on whether you’re defining, measuring, analyzing, improving, or controlling.