SESSION 02

Session 02 — Yellow Belt / Lean Six Sigma training (Summary)

Key frameworks, processes and playbooks

• Voice of the Customer (VOC)
  • Translate VOC (spoken and unspoken) into measurable CTQs (Critical To Quality).
  • Use VOC to set problem and goal statements and to prioritize stakeholder alignment.

Problem statement structure (pyramid): Intro → negative (financial) consequences → root-cause lead-in.

Goal statement guidance (one per CTQ): SMART — Specific, Measurable, Achievable, Relevant, Time‑bound.

• Problem & goal framing

  • Connect problems to financial impact to secure stakeholder buy-in.
  • Use one SMART goal per CTQ; recommended initial timeline ≈ 3 months (original Six Sigma guidance was ~6 months; adjust per project).

• Benchmarking and targets

  • Use comparable internal/local benchmarks.
  • If the gap to benchmark is large, consider setting the initial target = benchmark gap × ~70% (round as appropriate).
  • Renegotiate targets only with the process owner and Master Black Belt.

• Project governance and process mapping

  • Name the process as verb + noun.
  • High-level mapping using SIPOC (presenter also referred to it as “CYP O / supplier-input-process-output-customer”).
  • Create detailed process maps at L1–L4 granularity.

• Measurement System Analysis (MSA / R&R)

  • Assess repeatability (same operator), reproducibility (different operators), and accuracy/bias vs true value.
  • If MSA issues exist, standardize measurement before deep analysis.

• Standardization playbook for measurement & operations

  • SOPs: atomic-level, step-by-step, include photos.
  • Formal training and audits.
  • Recognition approach: public praise for compliance; private coaching for non-compliance.

• Control and capability analysis sequence

  • Measure → check stability (control charts) → then capability (vs customer spec).
  • Do not run capability analysis on an unstable process — first investigate and resolve special causes.

• Statistical tools referenced

  • Continuous data: I‑chart (individual control chart).
  • Proportions/discrete (good vs bad): P‑chart.
  • Capability commonly expressed via sigma level (Z).

• Certification / AI guidance

  • Typical pathway: white → yellow → green → black belts (content overlaps; tests are separate).
  • Use AI tools only after full domain knowledge (e.g., after Black Belt + AI belt) to avoid incorrect outputs.

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Key metrics, KPIs, targets & timelines

• CTQs from the case study

  • CTQ1: Delivery time (example customer target used = 10 minutes).
  • CTQ2: Pizza quality (defect / bad pizza rate).

• Delivery time sample metrics (example)

  • Sample mean delivery time ≈ 14.73 minutes (sample ~30 observations).
  • Customer upper spec = 10 minutes → process is stable but not capable.
  • Example calculated sigma level for delivery ≈ −4.52 (indicates a large portion of outputs outside spec).

• Quality / defects metrics (example)

  • Aggregate defective rate ≈ 10.2% (0.1022) across sample days.
  • Quality sigma level shown ≈ 1.27 (positive but low; not capable by typical industry expectations).

• Industry references for sigma levels

  • Four‑sigma: reasonable market reference for good performance.
  • Six‑sigma: aspirational / near-zero defects (~2 parts per billion).

• Recommended project duration

  • General guidance: ~3 months per Yellow Belt project (some projects may require up to 1 year).

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Concrete examples & case study takeaways (Pizza case study)

• VOC → identified two CTQs: delivery time and pizza quality.
• SIPOC example: named process = prepare/produce pizza; output = vegetarian pizza; key inputs = flour, tomato, cheese, oven, thermostat, chef, recipe.
• Process mapping: high-level then detailed maps; sampling and measurement checks implemented.
• MSA illustration: different observers counted letters differently — example used to show repeatability, reproducibility, and bias.
• Stability analysis: I‑chart for delivery time showed a stable process with mean > spec (predictable but poor performance).
• Capability analysis: histogram + spec limits demonstrated distribution not within spec — major opportunity for improvement (car-in-garage analogy).
• For quality (discrete defects) used a P‑chart to show control chart behavior for proportions.
• Business tradeoff example: ultra‑low‑cost airline sells cheap tickets but accepts poor reliability — acceptable low capability if customer expectations and price align.

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Actionable recommendations / tactical checklist

• Before using historical or process data

  • Verify measurement system reliability (repeatability, reproducibility, bias).
  • If MSA issues exist: standardize measurement (SOP + training + audit) before analysis.

• Writing problem & goal statements

  • Use the pyramid for problem statements; include financial negative consequences.
  • Use SMART for goals — one goal per CTQ; make them timebound (start with ~3 months).

• Target setting

  • Use comparable benchmarks (avoid unrealistic superstars).
  • If the gap is large, consider an initial target equal to ~70% of the gap.
  • Negotiate targets only with the process owner and Master Black Belt.

• Process mapping & SOPs

  • Map at L1–L4 levels.
  • SOPs: atomic steps, pictures, plain language, and tested by non‑experts (avoid curse of knowledge).

• Data sampling

  • Use sufficient, randomly selected samples from correct segments.
  • Sampling is acceptable and powerful when done correctly.

• Control / capability analytics

  • First perform stability analysis (control chart over time); investigate special causes before capability.
  • Continuous measures → I‑chart; binary defectives → P‑chart.
  • Translate results to sigma level and compare to VOC/spec limits.

• Behavior & leadership

  • Translate operational problems into financial impact to align stakeholders.
  • Combine standardization with respectful coaching and negotiation.
  • Use public praise for compliance and private, constructive feedback for non-compliance.

• Use of AI

  • Only after domain mastery — premature use risks incorrect outputs.

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Other operational / organizational notes

• Certification expectations: instructor expects ~20 hours classroom + ~10 hours self‑study; tests are proctored and tracked.
• Marketing/channel: recruitment/advertising cost for the course increased due to platform/tax changes; choice of platform (Meta vs Google) involves practical tradeoffs.
• Upcoming topics: root cause analysis planned for the next session (priority after the Measure phase).

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Presenters / sources

• Presenter: Marcelo Machado Fernandez (Marcelo). Support: session team (notably his niece Lara).
• Referenced organizations / tools / authors: ASQ (American Society for Quality), Minitab (statistical software), Edward Deming, Joseph Juran, and a referenced author noted as Gigu/Gijo Anthony.