Six Sigma Fundamentals (Video)

Roles and Responsibilities

  • Master Black Belts: train and coach Black/Green Belts, drive continuous improvement, own tool gates; lead cross-functional improvement projects; share best practices.
  • Black Belts: lead department improvement projects, contribute to CI, provide project support, mentor Green/Yellow Belts.
  • Green Belts: support Six Sigma tasks, lead smaller DMAIC/Kaizen events, spend workload on Six Sigma projects; overseen by Black Belts.
  • Yellow Belts: limited part-time team members; participate in DMAIC/Kaizen events; do not typically lead events; overseen by Green/Black Belts.
  • White Belts: basic Six Sigma understanding; provide limited support as needed.
  • QLP Managers: lead business unit process improvement.
  • Executive Sponsor: leads organizational change; responsible for business integration and direction/results.
  • Process Owner: manages daily operations; drives for solutions; owner of results.
  • Project Sponsor: key stakeholder; helps define scope and enables goals; owner of results.
  • Project Team Member: provides project-specific support.
  • Subject Matter Experts (SMEs): bring specialized knowledge; provide technical expertise as needed.

Team Members

  • Yellow Belts: participate in DMAIC/Kaizen; limited leadership; events overseen by Green/Black.
  • Green Belts: lead DMAIC/Kaizen events; workhorse of Six Sigma projects; overseen by Black Belts.
  • Black Belts: full-time; dedicated to Six Sigma projects; guide teams; mentor Green/Yellow Belts.
  • Master Black Belts: full-time; mentor Green/Black Belts; conduct Six Sigma training; responsible for overall Six Sigma strategy.
  • Champions: senior leadership; sponsor of projects; provide resources and remove obstacles; typically director level and up.
  • Process Owners: responsible for the targeted process; essentially the customer for the project; may serve as champions; usually supervisor level and up.
  • Executive Leadership: provide guidance, support, and commitment to Six Sigma; receive training but not always part of deployment.
  • Subject Matter Experts: provide expertise on technical aspects.

Team Types

  • Cross-functional: members from several departments; broad skill sets; hardest to secure management commitment due to high demand.
  • Parallel: team works on the same objective; acts as a backup.
  • Ad hoc: teams meet for a single session or as needed; highly skilled individuals in demand.
  • Cellular: permanent/coE team members; broad skill set.
  • Virtual: members from multiple facilities; meetings via teams; time-zone coordination is challenging but leverages network-wide experience.
  • Self-directed / Self-managed: teams complete project tasks with minimal input; driven by project goals.

Project Roles

  • Team Leader: assembles and leads the team.
  • Facilitator: guides Six Sigma practices; usually a Black Belt but may be Green Belt; acts as team leader.
  • Scribe: records team activities.
  • Gatekeeper: tracks milestones and progress.
  • Team Member: individual contributor to the project.

Team Roles Styles

  • Contributor (Task-Oriented): gets things done, provides data; seen as responsible, authoritative, reliable; risk: may lose sight of the goal.
  • Collaborator (Goal-Directed): contributes where needed, keeps end result in mind; seen as forward-looking, accommodating, imaginative; risk: may neglect basic tasks or individual needs.
  • Communicator (Process-Oriented): facilitates involvement, resolves conflicts; seen as supportive and tactful; risk: may overlook task completion.
  • Challenger (Question-Oriented): questions goals/process/methods; seen as principled and ethical; risk: may push team too far or overwhelm others.

Team Stages (Bruce Tuckman)

  • Forming: team is introduced; roles defined; low trust; members act independently.
  • Storming: conflicts and personality clashes; unclear goals.
  • Norming: roles/skills accepted; trust and collaboration grow.
  • Performing: team is unified; decisions are cohesive; high productivity.
  • Transforming: project wraps up; team disbands; transition back to roles; potential decline in engagement.

Six Sigma Fundamentals

  • Goal: reduce defects to as close to zero as possible; target DPMO around 3.4.
  • DPMO: Defects Per Million Opportunities
    • \text{DPMO} = \frac{\text{Defects}}{\text{Opportunities}} \times 10^6
    • Six Sigma concept corresponds to about 3.4 defects per million opportunities.
  • 1.5-σ shift: long-term variation is accounted for by a 1.5\sigma shift; used to explain why intended 6-sigma quality appears as 4.5-σ in practice.
  • Original claim: the methodology assumes processes follow a Normal distribution; the shift accounts for long-term variation.
  • Z-value: instead of citing how many sigmas away from the mean, the metric is often referred to as the “Z value.”
  • Originators: Mikel J. Harry and J. Ronald Lawson.

Quality

  • Quality is defined by the customer; must meet customer requirements and regulatory/governing body requirements.
  • Five Fundamentals of Quality:
    • Customer Requirements
    • Consensus and Data-Driven decisions
    • Defect Free output
    • Total Employee Involvement
    • Continuous Improvement

Cost of Quality

  • Categories:
    • Cost of Good Quality: Prevention Costs, Appraisal Costs
    • Cost of Poor Quality: Internal Failure Costs, External Failure Costs
  • Internal Failure Costs: rework, re-testing, downtime, scrap, redesign, labor, materials until before reaching the customer.
  • External Failure Costs: warranty, repairs, servicing after delivery, complaints, returns, lost sales.
  • Appraisal Costs: in-process testing, inspections, field testing, calibrations, audits.
  • Prevention Costs: quality planning, supplier audits, training, process capability evaluations, error-proofing.

Six Sigma Metrics

  • DPMO: ext{DPMO} = \frac{\text{Defects}}{\text{Opportunities}} \times 10^6
  • DPU: Defects per Unit
    • \text{DPU} = \frac{\text{Total defects found}}{\text{Number of units in a sample}}
  • First Time Yield (FTY):
    • \text{FTY} = \frac{\text{Successful units}}{\text{Attempted units}}
  • Rolled Throughput Yield (RTY):
    • \text{RTY} = \frac{\text{Attempted units} - (\text{scrap} + \text{rework})}{\text{Attempted units}}
  • FTY vs RTY: FTY measures overall efficiency; RTY accounts for defects across all steps.

Six Sigma Tools (Quality Tools)

  • The 7 Basic Quality Tools:
    • Bar Chart
    • Pareto Chart
    • Cause and Effect Diagram (Ishikawa / 6-M)
    • Process Map
    • Run Chart
    • Check Sheet
    • Control Chart

Decision Tools (Team Decision Tools)

  • Brainstorming:
    • Generate questions about the problem; use a starburst with: Who, What, Where, When, Why.
  • Nominal Group Technique (NGT):
    • Equal participation; individuals write ideas, then share; collect ideas without ridicule.
  • Multivoting:
    • After NGT, total ideas counted; each member gets 4 votes; prioritize by individual priority.

Process Maps and Related Tools

  • Process Map: current vs future map; core to identify improvements; created by SME.
  • Flow Chart: single sequence; step-by-step operations.
  • Swimlane Process Map: shows multiple sectors (who, when, what) across flow; useful for responsibilities and timing.
  • Matrix mapping: tasks (rows) vs operators/departments (columns); connect flow charts across steps.

Run Chart

  • Monitors a single process over time.
  • Steps: select variable, set time intervals, collect data, plot sequentially, add a mean reference line.
  • Used to identify patterns, trends, shifts, or concerns.

Check Sheet

  • Data collection tool with structured checks or tables.
  • Use to capture failure modes/variables over time intervals for later analysis.

Scatter Plot

  • Analyzes relationship between two variables.
  • Plot pairs (x, y) and assess possible correlation (often linear).

Histogram

  • Displays frequency distribution of a single variable.
  • Shapes can indicate normal, skewed, bimodal, or multimodal distributions.
  • Construction: determine range, number of bars (7–14 recommended), and bar width.

Control Chart (CPV)

  • Used for continuous process verification and baseline establishment.
  • Key components:
    • Upper Control Limit (UCL) = \mu + 3\sigma
    • Lower Control Limit (LCL) = \mu - 3\sigma
    • Mean (\mu)
  • Special causes may appear; if data fall within limits, process is considered in control (not necessarily stable).
  • Steps: select numerical data, determine time intervals, collect data (via Check Sheet), construct chart, interpret.