6 sigma: Introduction

Quality: What is quality? The answer depends on each party’s perspective.

Perspectives on Quality:

Design perspective: maximizing features.

Customer perspective: conformance to my needs.

Process perspective: conformance to requirements (managerial effort to make requirements=>customer needs).

Quality attribute examples: Conformance. Perfection. Performance. Reliability. Maintainability. Durability. Perceived Quality. Aesthetics.

Statistical Process Control (SPC): control variations.

Cost of (good/bad) quality.

6 sigma assertions:

Processes have attributes that can be measured, analyzed, controlled and improved.

Acheiving stable (no-variation) and predictable (BI) results is vital to business.

6 Sigma methodologies

Deming PDCA: Plan-Do-Check/Analyze-Act/Adjust: Spiral. To break into:
  DFSS – DMADV: Design-Measure-Analyze-Develop-Verify: New products. Or if the problem is about centering (average): most values are off the center, so mere improvement is not enough thus a re-development of a new process is needed.
  DMAIC: Define-Measure-Analyze-Improve-Control: Improvements to existing products/services. When the centering is good but the problem is about variation.



Define projects, goals, deliverables to internal and

external customers

Measure current performance of the process

Analyze root causes of the defects

Improve process to eliminate defects

Control performance of the process.

Why 6 Sigma:

  • focus on (internal-external-final) customer (SIPOC): set Critical to Quality (CTQ) attributes.
  • Process Oriented (SIPOC): Value-adding (Design vs Develop) vs Support Process.
  • Measurable ROI (DPMO, etc).
  • All stakeholders must be involved:: master how to change people for the best and reduce their resistance to change.
  • Continuous Improvement (DMAIC cycles).

• Enhancing value through new products

and services

• Reducing errors, defects, waste, and costs

• Increasing productivity and effectiveness

• Improving responsiveness and cycle time


Response Time, Quality, & Productivity: Synergy

Major improvements in response time may

require significant simplification of work processes and often drive simultaneous improvements in quality and productivity.

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