CAPA Example

CAPA Example for Manufacturing Deviation

Manufacturing CAPAs often sound straightforward on paper, but the real challenge is proving why the process allowed a deviation to occur and continue.

Below is a structured CAPA example for a machining deviation involving positional tolerance drift on a critical aerospace bracket feature.

It shows how process controls, setup verification, and preventive action can be tied together in an audit-ready investigation.

Nonconformance Description

During final inspection of machined attachment brackets, 8 of 24 units were found to have hole-position measurements outside the approved positional tolerance by up to 0.18 mm.

The deviation was traced to a single machining cell and one active fixture set. All affected lots were contained before shipment, and no nonconforming parts were released to customers.

Potential impact included assembly misalignment, rework, schedule disruption, and reduced confidence in process capability for a critical product family.

Problem Statement

The manufacturing process produced parts outside a critical positional tolerance due to unknown causes, representing a major process deviation with potential fit, function, and delivery implications.

Root Cause Analysis (Summary)

A structured Ishikawa and 5-Why analysis identified contributing factors across tooling condition, setup verification, and process monitoring.

Key contributing areas:

  • Fixture condition - locating pins and clamp surfaces showed wear beyond preventive-maintenance limits
  • Setup verification - first-piece approval did not require the full positional-feature check
  • Changeover controls - offset adjustments were made without a second-person verification step
  • Process monitoring - reaction-plan thresholds were too broad to catch gradual drift early

Leading hypothesis:

The most probable root cause is fixture wear combined with incomplete setup verification, which allowed positional drift to develop without triggering the intended reaction plan soon enough.

Alternative contributing causes remain plausible, including inconsistent offset-control practices during changeovers.

Corrective Actions (Overview)

Corrective actions were structured across four layers:

1. Containment

  • Affected work-in-process and finished brackets were placed on hold
  • Shipping was blocked until dimensional status and lot genealogy were confirmed

2. Immediate Correction

  • Fixture was removed from service and inspected against master tooling references
  • Machine offsets and first-piece records were reviewed for all impacted shifts

3. Systemic Corrective Actions

  • Fixture refurbishment and formal requalification before return to production
  • Updated setup verification to require complete positional inspection on first-piece approval
  • Added dual signoff for offset changes during changeovers and troubleshooting

4. Preventive Actions

  • Layered process audits updated to include setup and reaction-plan adherence checks
  • Preventive-maintenance frequency tightened for high-use fixtures
  • Similar machining cells reviewed for the same detection weakness

Effectiveness Checks

Effectiveness was defined using measurable and auditable criteria:

  • Thirty consecutive conforming parts after fixture requalification and setup changes
  • Successful first-piece audits on every shift for the next four weeks
  • No repeat positional-tolerance escapes during the next 60 production days
  • Audit confirmation that all offset changes include documented second-person verification

These checks verify that the deviation was corrected at the process level, not just sorted out after the fact.

Why This Matters

One of the most common manufacturing CAPA failures is explaining the deviation as a one-time operator or setup issue without addressing the control-system gaps that made it possible.

In this case, the deeper issue was systemic:

  • insufficient control over tooling wear and setup drift
  • first-piece verification that was too narrow for the true risk
  • reaction-plan limits that allowed deviation trends to persist too long

That is what auditors and operations leaders want to see - not just the deviation, but why the manufacturing system did not stop it earlier.

See How This Was Generated

This CAPA example was generated using CAPA Engine, a structured investigation tool designed for regulated industries including medical devices, pharma, aerospace, and manufacturing.

It helps quality teams move from unstructured nonconformance descriptions to complete CAPA investigations with:

  • root cause analysis
  • corrective action plans
  • effectiveness checks
  • investigation reasoning and confidence

Frequently Asked Questions

What is a CAPA example?

A CAPA example shows how a nonconformance is investigated, including root cause analysis, corrective actions, and effectiveness checks.

What should be included in a CAPA?

A CAPA should include a clear problem statement, root cause analysis, corrective actions, and measurable effectiveness checks.

Related CAPA Examples

Curious how this compares to using ChatGPT for CAPA? Read our breakdown of where generic AI helps, where it falls short, and what a more structured CAPA approach looks like.

Try it yourself

This example was generated using CAPA Engine.

Paste your own nonconformance and see the full investigation

Move from an unstructured event description to a structured CAPA investigation with root cause analysis, corrective actions, and effectiveness checks.

Try CAPA Engine - Free Analysis