Six Sigma is built on a small set of core principles that guide how organizations reduce defects, improve quality, and make better decisions.

Core Six Sigma Principles

1. Focus on the customer

  • The starting point is always the customer’s definition of quality: what they value, need, and are willing to pay for.
  • Requirements (CTQs – Critical to Quality) are translated into measurable specs so the process can consistently meet or exceed expectations.

2. Use data, not gut feeling

  • Six Sigma decisions are strongly data‑driven: collect, measure, and analyze before changing anything.
  • Tools like control charts, Pareto charts, cause‑and‑effect diagrams, and hypothesis tests are used to find true root causes rather than symptoms.

3. Reduce variation and defects

  • Variation in a process is the enemy of consistency; Six Sigma aims to make outputs stable and predictable.
  • The statistical goal often cited is about 3.4 defects per million opportunities, symbolizing near‑perfection in performance.

4. Improve processes systematically (DMAIC)

  • Problems are tackled using structured roadmaps like DMAIC: Define, Measure, Analyze, Improve, Control.
  • Each phase has specific deliverables (e.g., process maps, baseline capability, validated root causes, tested improvements, control plans).

5. Involve and develop people

  • Six Sigma stresses cross‑functional teams and clear roles (Champions, Black Belts, Green Belts, etc.).
  • Training and participation at different levels build capability so improvement is not a one‑off project but a repeatable way of working.

6. Strive for continuous improvement and flexibility

  • It is not “fix once and forget”; processes are monitored and refined over time for ongoing gains.
  • Organizations are encouraged to stay flexible and responsive, adjusting processes as markets, technology, and customer expectations change.

How These Principles Show Up in Practice

A typical example: a hospital wants to reduce patient wait times in the emergency department.

  • It defines the customer need (short, predictable waits), maps the current process, and gathers time‑stamp data.
  • Analysis shows variation comes mainly from triage bottlenecks and lab result delays; the team redesigns triage steps and standardizes lab batching.
  • New controls (dashboards, standard work, escalation rules) keep waits within target and sustain the gains.

These principles together make Six Sigma a disciplined approach to improving quality, speed, and cost performance across many industries, not just manufacturing.

Information gathered from public forums or data available on the internet and portrayed here.