Control Plan

When to Activate This Skill

• "Create a control plan for [part/process]"
• "What inspection frequency for [characteristic]?"
• "Define control methods for [operation]"
• "Link PFMEA to control plan"
• "What's the reaction plan for [out-of-spec condition]?"
• "Develop prototype/pre-launch/production control plan"

Control Plan Phases

Prototype Control Plan

• Purpose: Control during prototype build
• Focus: Dimensional measurements, material tests, performance
• Frequency: Often 100% on critical dimensions
• Duration: Until prototype approval

Pre-Launch Control Plan

• Purpose: Control during PPAP/validation runs
• Focus: Enhanced inspection, process validation
• Frequency: Increased sampling, SPC establishment
• Duration: Until production approval (PSW)

Production Control Plan

• Purpose: Ongoing production control
• Focus: Standardized controls, sustained quality
• Frequency: Based on process capability
• Duration: Life of production

AIAG Control Plan Format

Required Columns

Special Characteristics

Critical Characteristics (CC)

• Symbol: Shield, (CC), or inverted delta
• Criteria: Safety or regulatory compliance
• Requirements:
  • Documented in Control Plan
  • Enhanced inspection (often 100%)
  • SPC required (Cpk ≥1.67)
  • Traceable records
  • Identified on drawing

Significant Characteristics (SC)

• Symbol: Diamond, (SC)
• Criteria: Fit, function, appearance significant to customer
• Requirements:
  • Documented in Control Plan
  • Appropriate inspection frequency
  • SPC recommended (Cpk ≥1.33)
  • Records maintained

Standard Characteristics

• Symbol: None
• Criteria: All other characteristics
• Requirements:
  • Documented in Control Plan
  • Sampling based on risk
  • Records as required

Sample Size and Frequency Guidelines

Based on Severity (from PFMEA)

Based on Process Capability

Standard Frequency Terms

Control Methods

Inspection Methods

Recording Methods

Reaction Plans

Standard Reaction Plan Format

IF [out-of-spec condition] THEN:
1. STOP - Halt production/segregate suspect
2. CONTAIN - Quarantine affected parts
3. NOTIFY - Alert supervisor/quality
4. EVALUATE - Determine root cause and extent
5. CORRECT - Implement fix before restart
6. VERIFY - Confirm correction effective

Reaction Plan Examples

Dimension Out of Spec:

1. Stop production
2. Segregate last good part to current
3. Notify Quality/Supervisor
4. Check tool condition, offset, fixture
5. Adjust/replace as needed
6. Run first piece, verify to spec
7. Inspect segregated parts 100%

Visual Defect:

1. Reject defective part
2. Assess severity (isolated vs trend)
3. If trend: notify supervisor, review process
4. Identify root cause (tool, material, handling)
5. Implement correction
6. Resume with enhanced attention

SPC Out of Control:

1. Mark control chart
2. Continue production if within spec
3. Investigate pattern (rule violated)
4. Identify assignable cause
5. Implement correction
6. Document on chart

PFMEA to Control Plan Linkage

Required Flow

PFMEA Item            →    Control Plan Entry
─────────────────          ───────────────────
Process Step          →    Part/Process Number
Function              →    Characteristic
Failure Mode          →    What we're preventing
Detection Control     →    Control Method
S/O/D Ratings         →    Sample Size/Frequency
Special Char          →    Special Char Class

Linkage Verification

For each Control Plan line, verify:

• PFMEA has corresponding failure mode
• Special characteristics match
• Control method addresses PFMEA detection
• Frequency appropriate for risk level
• Reaction plan defined

Output Format

When generating Control Plan content:

# Control Plan
**Part Number**: [P/N]
**Part Name**: [Description]
**Customer**: [Customer Name]
**Control Plan Number**: CP-[DEPT]-[SEQ]
**Phase**: [ ] Prototype  [ ] Pre-Launch  [X] Production
**Revision**: [Rev] | **Date**: [YYYY-MM-DD]
**PFMEA Reference**: PFMEA-[XXX]

## Operation: [Number] - [Name]

### Characteristic 1: [Description]

| Field | Value |
|-------|-------|
| **Char No.** | [Unique ID] |
| **Product/Process** | Product / Process |
| **Class** | CC / SC / - |
| **Specification** | [Nominal ± Tolerance] |
| **Evaluation Method** | [Gage/Equipment] |
| **Sample Size** | [n] |
| **Sample Frequency** | [When] |
| **Control Method** | [Recording method] |
| **Reaction Plan** | [Reference or inline] |

Integration with Related Skills

PFMEA

Control Plan is direct output of PFMEA:

• Every PFMEA detection control → Control Plan method
• PFMEA severity drives inspection frequency
• PFMEA updates trigger Control Plan review

Load: read ~/.claude/skills/Pfmea/SKILL.md

MSA

All gages in Control Plan require MSA:

• Gage R&R for variable gages
• Attribute agreement for attribute gages
• MSA acceptance before production approval

Load: read ~/.claude/skills/Msa/SKILL.md

AutomotiveManufacturing

Work instructions must reflect Control Plan:

• Inspection steps in work instructions
• Operator-level control methods
• Quality checkpoints documented

Load: read ~/.claude/skills/Automotivemanufacturing/SKILL.md

Supplementary Resources

For detailed guidance: read ~/.claude/skills/Controlplan/CLAUDE.md

For templates: read ~/.claude/skills/Controlplan/templates/control-plan-template.md

For control method selection: read ~/.claude/skills/Controlplan/reference/control-methods.md

For sampling guidelines: read ~/.claude/skills/Controlplan/reference/sample-frequencies.md