PPAP Measurement Systems Analysis (MSA) and Gage R&R

01How to use this chapter

This chapter separates the uploaded assessment criteria from practical KEVOS implementation guidance. The section titled Source-derived assessment criteria preserves the intent, terminology and checklist detail supplied in the uploaded PPAP Assessment. The surrounding handbook guidance explains how a manufacturing or supplier-quality team can organise evidence, perform a readiness review and spot gaps before formal submission. Where the uploaded source states a numeric threshold, edition reference or customer-specific expectation, it is identified as source-derived rather than presented as a universal rule.

Use the chapter in three passes. First, read the purpose and workflow to understand what the element is meant to prove. Second, work through the source-derived prompts against the actual part number, engineering revision and production process. Third, close the red flags and collect objective evidence before the package is released. For large PPAPs, record the evidence location beside each source prompt so another reviewer can repeat the assessment without relying on verbal explanation.

02Handbook workflow

1. Start from the control planList every gage and measurement system used to accept or control the product/process, including attribute checks and process-control devices.
2. Define the measurement systemRecord gage identity, revision, characteristic, range/resolution and the part or gage family to which the study applies.
3. Select the study methodUse the approved MSA method appropriate to the data type and decision. Variable and attribute systems require different evaluation logic.
4. Use representative conditionsStudy the actual production measurement method with realistic parts, operators/appraisers and operating conditions.
5. Interpret error relative to useUse the source thresholds as one decision input, not as a substitute for customer-specific or application-specific requirements.
6. Address correlationWhere different gages, labs, locations or methods must agree, investigate and document correlation concerns.
7. Link approval to the PPAP evidence chainThe measurement system should be adequate before dimensional and capability conclusions are relied upon.

03Evidence package to retain

The assessment is stronger when each conclusion points to a controlled record rather than a statement that the requirement is “covered”. The following evidence set is a practical minimum for this chapter; actual customer and contractual requirements govern the live submission.

• MSA report for every applicable control-plan gage
• Correct part number or gage-family reference
• Gage name/ID and revision
• Characteristic measured
• Study method and raw/summary results
• Appraisers/operators and sample basis where applicable
• Correlation study/evidence where needed
• Customer review/approval evidence when required
• Improvement/action plan for unacceptable measurement performance

04Source-derived assessment criteria

• 1.Are MSAs for all (including attribute, process controls, etc.) gages listed on the control plan provided?
• 2.Do all MSAs refer to the correct part number and/or gage family
• 3.Did the supplier submit an acceptable MSA as above and documented in the AIAG MSA Manual?
• 4.Have correlation concerns been addressed?
• 5.Have results been reviewed and approved by the customer?

05Common red flags

These are practical review signals derived from the relationships and controls repeatedly required by the source. A red flag does not automatically mean the submission must be rejected; it means the condition deserves documented resolution before approval.

• Capability study is reported using a measurement system with no MSA
• MSA references a different gage revision than the production gage
• Attribute gages are excluded because they do not produce variable data
• A 10–30% result is automatically accepted with no application-based justification
• Correlation differences between supplier and customer are known but unresolved
• Study uses non-representative master parts only and does not reflect production measurement behaviour

06Cross-document interfaces

PPAP elements should not be reviewed as isolated files. Check the following interfaces for consistent part identity, revision, characteristic naming, operation numbering and control logic.

07Assessor close-out checklist

• The element is present or a controlled waiver/agreement explains why it is not required.
• The submitted record identifies the correct part number and engineering revision where applicable.
• The evidence is legible, understandable, controlled and traceable to the submitted product/process.
• Special characteristics and known customer concerns are treated consistently across related documents.
• Any nonconformance, temporary control, deviation or interim condition is visible and formally dispositioned.
• Actions have owners, due dates and objective closure evidence where the source expects corrective action.
• The final conclusion can be independently repeated by another reviewer using the package alone.

08Frequently asked questions

09Source and limitations

Primary source: uploaded Production Part Approval Process (PPAP) Assessment / PPAP Submission Assessment, 15 pages, Quality-One. Source sections used on this page: 2.2.8 Measurement Systems Analysis Studies (MSA). Approximate source page coverage: 9-9.

This KEVOS chapter is an educational and assessment aid. It preserves the uploaded document's criteria but does not replace controlled customer-specific requirements, engineering specifications, contractual requirements or an official PPAP/APQP manual. Where the source references “PPAP 4th edition”, AIAG methods, Organization systems or Organization-specific targets, those references are retained as source context rather than silently updated or generalized.