Purpose
Transform a raw quality issue description into a complete, audit-ready 8D report with all eight disciplines fully populated — team, problem statement, containment, root cause, corrective action, verification, prevention, and recognition. Eliminates the days of formatting and cross-functional back-and-forth quality engineers spend building 8Ds by hand, while enforcing the analytical rigor auditors and customers demand.
When to Use
Invoke this skill when the user asks to:
- Document a customer complaint or field return requiring formal corrective action
- Respond to a supplier nonconformance report (SCAR/SCR) or a customer-issued 8D request
- Investigate an internal quality escape, scrap spike, or line stoppage
- Build a root cause analysis for a recurring defect
- Prepare a corrective action document for an IATF 16949 / ISO 9001 audit
- Convert an informal problem write-up into a structured D1–D8 deliverable
Inputs Required
Before starting, collect:
- Issue description: What went wrong, in plain language (2–5 sentences)
- Part / product affected: Part number, product line, or process name
- Detection point: Where the issue was found (customer site, incoming inspection, in-process, final audit, field)
- Quantities involved: Number of defective units, lot/batch size, and any date/serial ranges known
- Customer / stakeholder: Who raised the issue and any deadline or reference number
- Known specifications: The requirement or spec that was violated (tolerance, standard, drawing callout)
- Suspected cause (optional): Any early hypothesis from the team
If quantities, detection point, or specifications are missing, generate the report with clearly flagged placeholders reading "TO BE CONFIRMED" so the operator can complete the record without the AI inventing data.
Instructions
Step 1: D1 — Establish the Team
Define a cross-functional team appropriate to the issue.
- List a Champion (owns the 8D, typically a quality manager) and a Team Leader (drives the investigation)
- Assign functional members by role, not name: Quality Engineer, Process/Manufacturing Engineer, Design/Product Engineer (if design-related), Supplier Quality (if purchased-part-related), Operations/Production, and Logistics (if containment spans warehouses)
- For each role, state the specific reason they are on the team (their knowledge or authority relevant to this issue)
Step 2: D2 — Describe the Problem
Quantify the problem using structured problem definition.
- Write a problem statement in object–defect form: "[Part] exhibits [defect] resulting in [effect]"
- Build an is / is-not analysis table across five dimensions: What, Where, When, Who/How Many, How Big. For each, state what the problem IS and what it IS NOT, to bound the problem.
- State the measurable magnitude: defect rate (PPM if calculable), units affected, cost/risk exposure
- Confirm the violated requirement with the specific spec, tolerance, or standard
Step 3: D3 — Interim Containment Actions
Define actions to protect the customer immediately while root cause is pursued.
- List containment across the full supply chain: customer site, in-transit, finished goods, WIP, and raw stock
- For each location: the action (sort, quarantine, 100% inspection, rework, replacement), responsible function, and effectiveness verification method
- State containment effectiveness — how the team confirms no defective product reaches the customer (e.g., "100% inspection with second-check signoff; 0 escapes over 3 shifts")
- Note the containment start date and a review cadence
Step 4: D4 — Root Cause Analysis
Identify the true root cause using two complementary methods.
- Fishbone (Ishikawa): Generate candidate causes across the 6M categories — Man, Machine, Method, Material, Measurement, Environment. Populate each branch with at least one plausible cause given the issue.
- 5-Why analysis: Run two separate 5-Why chains — one for the occurrence root cause (why the defect was made) and one for the escape root cause (why detection failed). Each chain drills from the symptom to a systemic root.
- State the confirmed root cause(s) and how they were validated (verified with data, replicated the defect, or turned the effect on/off)
- Distinguish occurrence root cause from escape root cause explicitly
Step 5: D5 — Permanent Corrective Actions (PCA)
Select and justify permanent corrective actions.
- Propose a PCA for the occurrence root cause and a PCA for the escape root cause
- For each: the action, responsible function, target completion date, and expected effect on the root cause
- Note why the PCA addresses the root cause and not just the symptom
- Reference error-proofing (poka-yoke) where feasible — engineering controls outrank procedural controls
Step 6: D6 — Implement and Validate Corrective Actions
Confirm the PCAs work and containment can be removed.
- State the validation method for each PCA: measurable evidence the defect no longer occurs or escapes (capability study, PPM tracking over N units, audit results)
- Define the criteria to remove interim containment and the date it is lifted
- Note any control plan, PFMEA, work instruction, or inspection document updated as part of implementation
Step 7: D7 — Prevent Recurrence (Systemic Prevention)
Prevent the same failure mode across similar processes and products.
- Identify read-across: other parts, lines, or processes with the same failure risk and the action taken to inoculate them
- List systemic document updates: PFMEA, Control Plan, work instructions, lessons-learned database, standards
- Recommend management-system changes if the root cause points to a gap in process design, training, or specification review
Step 8: D8 — Recognize the Team and Close
Close the 8D formally.
- Summarize the outcome: root cause eliminated, containment removed, prevention deployed
- Recognize the team's contribution specifically (what the effort accomplished)
- State closure criteria met and the sign-off roles required (Team Leader, Champion, Customer if applicable)
Output Format
- Structure: Eight labeled sections (D1 through D8) in order, each with a heading and the discipline's required elements; is/is-not and fishbone rendered as tables
- Length: 1,100–1,600 words
- Format: Structured report document — headings, tables for is/is-not and 6M analysis, numbered chains for 5-Why, bulleted actions with responsibility/date columns
- Sections: D1 Team → D2 Problem Description → D3 Containment → D4 Root Cause → D5 Permanent Corrective Action → D6 Implementation & Validation → D7 Prevention → D8 Recognition & Closure
- Tone: Factual, precise, audit-ready — the register of a quality engineer writing for a customer SQE and an internal auditor; no marketing language, no speculation stated as fact
Quality Checklist
Before delivering output, verify:
- [ ] All eight disciplines (D1–D8) are present and populated — none skipped or merged
- [ ] D4 contains both a 6M fishbone AND two separate 5-Why chains (occurrence and escape)
- [ ] Occurrence root cause and escape root cause are addressed distinctly in both D4 and D5
- [ ] D2 includes an is/is-not table across all five dimensions (What, Where, When, Who, How Big)
- [ ] Every corrective and containment action has a responsible function and a completion/target date
- [ ] Any unknown data is marked "TO BE CONFIRMED" rather than fabricated
Notes
- The most common 8D failure is treating the symptom in D5 while D4's root cause is actually a shallow "operator error" — push the 5-Why past human error to the system that allowed it
- Separating occurrence from escape root cause is what distinguishes an audit-passing 8D from a rejected one; a defect that was made AND shipped means two control failures, not one
- For supplier-facing 8Ds, keep containment (D3) conservative — 100% inspection until PCA is validated is the defensible default
- Recommend the operator attach objective evidence (capability studies, inspection records, updated control plans) as appendices; this generator produces the narrative and structure, not the raw measurement data
How to use this skill
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Installing in Claude Code:
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Using in Claude.ai, ChatGPT, Gemini, or other AI tools:
- Drag this file into a new chat, or copy and paste its contents
- Send your task or request as your next message — the AI will apply the skill where it fits
For Claude Code skill details: https://docs.anthropic.com/en/docs/claude-code/skills