8D Problem Solving Skill

Overview

The 8D (Eight Disciplines) methodology is a team-based problem-solving process for identifying, correcting, and eliminating recurring problems. Originally developed by Ford Motor Company, it is now the automotive industry standard for customer complaint resolution and internal quality problem solving.

Skill Integration

Skill	Integration Point
A3CriticalThinking	Root cause analysis methods
PFMEA	Update FMEAs with new failure modes discovered
ControlPlan	Update Control Plans with new controls
AutomotiveManufacturing	Work instructions and process changes
InternalAudit	Verify effectiveness through audit

8D Phase Overview

Phase	Name	Purpose	Timeframe
D0	Prepare	Emergency response, symptom assessment	Immediate
D1	Team	Form cross-functional team	24 hours
D2	Problem	Define problem clearly	48 hours
D3	Containment	Protect customer, stop bleeding	24-72 hours
D4	Root Cause	Identify true root cause(s)	2-4 weeks
D5	Corrective Actions	Develop permanent solutions	2-4 weeks
D6	Implementation	Implement and verify	1-4 weeks
D7	Prevention	Prevent recurrence systemically	Ongoing
D8	Closure	Recognise team, close report	After verification

D0: Prepare for the 8D Process

Emergency Response Actions (ERA)

Before formal 8D begins, immediate actions to protect:

Customer Protection
- Identify all potentially affected product
- Stop shipment of suspect product
- Notify customer of situation
- Provide replacement/rework timeline
Symptom Assessment
- What is the symptom?
- When was it first detected?
- How much product is affected?
- Is this a safety/regulatory issue?
**8D Trigger Criteria

Trigger	8D Required?
Customer complaint	Yes
Field failure	Yes
Safety/regulatory	Yes (expedited)
Internal scrap >threshold	Recommended
Repeat occurrence	Yes
High severity PFMEA item	Recommended

D0 Outputs

Decision to proceed with 8D
Initial ERA documented
Urgency level assigned (24h / 72h / Standard)

D1: Establish the Team

Team Composition

Role	Responsibility	Required?
Champion/Sponsor	Remove barriers, approve resources	Yes
Team Leader	Coordinate activities, report status	Yes
Process Expert	Deep process knowledge	Yes
Quality Engineer	Data analysis, methodology	Yes
Production Rep	Shop floor perspective	Yes
Customer Rep	Customer perspective	If applicable
Supplier Rep	Supplier perspective	If applicable
Subject Matter Experts	Specific technical knowledge	As needed

Team Size

Ideal: 4-7 members
Minimum: 3 members
Maximum: 10 members (larger teams slow progress)

D1 Outputs

Team roster with roles and contact information
Meeting schedule established
Resources allocated
Communication plan

D2: Describe the Problem

Problem Description Techniques

5W2H Analysis:

Question	Answer
What is the problem?	Specific defect/symptom
Where was it found?	Location (customer, inspection, operation)
When was it found?	Date, time, shift, production lot
Who found it?	Person, inspection method
Why is it a problem?	Impact to customer/function
How many are affected?	Quantity, frequency, trend
How was it detected?	Detection method used

IS / IS NOT Analysis:

Factor	IS	IS NOT
What	[Observed defect]	[Similar but not this]
Where	[Location found]	[Where not found]
When	[Time first seen]	[Time not seen]
Extent	[Scope affected]	[Not affected]

Problem Statement Format

Good problem statement:

"Outer diameter of part #12345 measures 25.08-25.12mm (spec: 25.00 ±0.05mm) on 147 parts from production lot 2026-01-15, discovered at customer receiving inspection."

Bad problem statement:

"Parts are out of spec" (too vague)

D2 Outputs

Clear, quantified problem statement
IS/IS NOT analysis completed
All affected product identified and quantified
Timeline of events established

D3: Interim Containment Actions (ICA)

Containment Scope

Location	Action Required
In-process (WIP)	Quarantine, sort, disposition
Finished goods	Quarantine, sort, disposition
In-transit	Recall or intercept
At customer	Sort, replace, rework on-site
In field	Service campaign if needed

Containment Actions

Sort - 100% inspection to separate good/bad
Hold - Quarantine suspect product
Replace - Provide conforming product
Enhanced inspection - Temporary additional checks
Process change - Temporary parameter adjustment

Containment Verification

Before releasing containment:

Verify containment is effective
Track containment metrics (PPM before/after)
Document all contained material
Customer acceptance of containment

Escape Point Analysis

Critical Question: Where should this have been caught?

Stage	Did we have detection?	Why did it escape?
Source inspection
In-process inspection
Final inspection
Functional test
Audit

D3 Outputs

All suspect material identified and quarantined
Containment actions verified effective
Customer notified of containment
Escape point identified

D4: Root Cause Analysis

Root Cause Categories

Occurrence Root Cause: Why did the defect occur?

Process, machine, material, method, environment

Detection Root Cause (Escape Point): Why wasn't it caught?

Inspection method, frequency, capability, training

Root Cause Analysis Tools

Tool	Best For	Reference
5-Why	Simple cause chains	`reference/root-cause-tools.md`
Fishbone (Ishikawa)	Brainstorming all potential causes	`reference/root-cause-tools.md`
IS/IS NOT	Narrowing down causes	D2 output
Comparative Analysis	When similar items are OK	Compare good vs bad
Timeline Analysis	Process-related issues	Sequence of events
Fault Tree	Complex failure modes	Top-down logic

5-Why Guidelines

Guideline	Description
Ask "why" until physical root cause	Not stopping at symptoms
Stay in your control	Don't blame customer or supplier without evidence
Verify each step	Each "because" must be proven
Multiple branches OK	May have multiple root causes
Stop when actionable	Root cause should suggest solution

Root Cause Verification

Verification Methods:

Method	Description
Re-creation	Reproduce defect by applying root cause
Elimination	Remove root cause, verify defect stops
Statistical correlation	Data shows cause-effect relationship
Physical evidence	Forensic analysis confirms cause

Root cause is verified when:

Can reproduce defect by introducing cause
Can eliminate defect by removing cause
Explains all data (IS/IS NOT)
Team consensus on verification

D4 Outputs

Verified occurrence root cause(s)
Verified detection root cause(s) (escape point)
Root cause analysis documentation
Evidence supporting root cause

D5: Develop Corrective Actions

Corrective Action Types

Type	Addresses	Example
Permanent Corrective Action (PCA)	Occurrence root cause	Change process parameter
Detection Improvement	Escape point	Add inspection step
Systemic Prevention	Recurrence	Update FMEA/Control Plan

Corrective Action Hierarchy

Prefer higher-order controls:

Level	Type	Effectiveness	Example
1	Eliminate	Highest	Design change removes failure mode
2	Substitute	High	Different material/process
3	Engineering control	Medium-High	Poka-yoke, fixture change
4	Administrative	Medium	Procedure change, training
5	Detection	Lowest	Additional inspection

Corrective Action Criteria

Each corrective action must be:

Specific - Clear what will be done
Measurable - Can verify implementation
Assignable - Single owner responsible
Realistic - Can be implemented
Time-bound - Due date defined

Risk Assessment

Before implementing corrective actions:

Will action introduce new risks?
Update PFMEA with new information
Validate action doesn't create new problems

D5 Outputs

List of corrective actions with owners and dates
Risk assessment of each action
PFMEA updates identified
Control Plan updates identified

D6: Implement and Verify Corrective Actions

Implementation Steps

Plan - Detailed implementation plan
Communicate - Notify all affected parties
Train - Train operators on changes
Execute - Implement changes
Verify - Confirm actions completed
Validate - Confirm actions are effective

Verification vs Validation

Verification	Validation
Did we implement the action correctly?	Did the action solve the problem?
Check implementation	Check effectiveness
Immediate	Over time

Effectiveness Verification

Method	Description	Duration
Before/After comparison	Metric improvement	1-3 months data
Control chart	Process stability	25+ subgroups
Capability study	Cpk improvement	Per standard
Audit	Process compliance	Scheduled
Zero defects	No recurrence	3-6 months

D6 Outputs

All corrective actions implemented
Implementation verification completed
Effectiveness validation initiated
Updated documentation (WI, Control Plan, FMEA)

D7: Prevent Recurrence

Systemic Prevention Actions

System	Update Required
PFMEA	Add failure mode, update S/O/D, add controls
Control Plan	Add/modify inspection, update reaction plan
Work Instructions	Incorporate process changes
Training	Update training materials, retrain
Lessons Learned	Document for future reference
Similar Products	Apply to similar parts/processes

Horizontal Deployment

Apply learning across:

Similar parts on same equipment
Similar processes in other areas
Similar failure modes in PFMEA
Supplier processes if applicable

D7 Outputs

FMEA updated with new failure mode
Control Plan updated
Work instructions revised
Training completed
Lessons learned documented
Horizontal deployment completed

D8: Recognise Team and Close

Closure Criteria

Root cause verified
All corrective actions implemented
Effectiveness verified (no recurrence period)
FMEA/Control Plan updated
Work instructions updated
Training completed
Customer accepts closure (if customer complaint)
Lessons learned documented

Team Recognition

Acknowledge team contribution
Share success with organisation
Consider formal recognition programme

8D Archive

Retain 8D reports for:

Customer-required retention period
Minimum 3 years per IATF 16949
Accessible for reference and audits

D8 Outputs

8D report complete and approved
Customer acceptance (if applicable)
Archive in quality records
Team recognised

Templates

templates/8d-report.md - Full 8D report template

Reference Materials

reference/root-cause-tools.md - 5-Why, Fishbone, IS/IS NOT
reference/verification-methods.md - How to verify root cause and effectiveness

MNMUK-Specific Guidelines

Response Timeframes

Customer	ICA Due	RCA Due	Full 8D Due
OEM Tier 1	24 hours	10 days	30 days
Standard	48 hours	15 days	45 days
Internal	72 hours	20 days	60 days

8D Numbering

Format: 8D-[YYYY]-[SEQ] Example: 8D-2026-001

Approval Authority

Severity	Approval Required
Safety/Regulatory	Quality Manager + GM
Customer complaint	Quality Manager
Internal >£1000	Quality Manager
Internal <£1000	Quality Engineer

Quick Reference

# Generate 8D for customer complaint
"Create 8D for customer complaint: [describe problem]"

# Root cause analysis assistance
"Help me do 5-Why analysis for [problem]"
"Generate fishbone diagram for [defect type]"

# Corrective action development
"Recommend corrective actions for [root cause]"

# 8D review
"Review this 8D for completeness"

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