Production Part Approval Process –
(Production Part Approval Process) abbreviated as PPAP

The Production Part Approval Process (PPAP for short) is a quality assurance procedure used in the automotive industry supply chain. Its purpose is to establish confidence in parts suppliers and their manufacturing processes. The actually produced parts are measured, and every test item on the PPAP test form must be completed:

The Automotive Industry Action Group (AIAG) has proposed a common PPAP standard, which is part of Advanced Product Quality Planning (APQP). It encourages the use of common terminology and standard forms to generate documentation related to project status, although each manufacturer still has its own individual requirements.

The PPAP procedure is used to let the customer know that, in order to meet the customer’s requirements, the parts supplier has planned its design and production processes and has reduced the risk of failure through the efficient use of APQP. Therefore, a supplier’s request for part approval must be accompanied by formal PPAP documentation, and corresponding reports may also be provided when required. The following are the related explanations:

…Production Part Approval Process
PPAP defines the general requirements for production part approval, including production and bulk materials.
The purpose of PPAP is to determine whether the supplier has correctly understood all the requirements of the customer’s engineering design records and specifications, and whether it has the potential capability to consistently meet these requirements during the actual mass production of parts under the production conditions quoted.

Products used for PPAP must:

1. Be taken from a significant production process.
2. Be from a production run of one to eight hours, with a specified production quantity of at least 300 consecutively produced parts, unless otherwise specified by the customer representative.
3. Be produced at the production site using the same gauges, processes, materials, and operators as in the production environment.
PPAP requirements by Level
1. Design Record
2. Engineering Change Documents (if any)
3. Customer Engineering Approval (if required)
4. Design FMEA
5. Process Flow Diagram
6. Process FMEA
7. Dimensional Results
8. Material and Performance Test Results
9. Initial Process Study
10. PSW (Part Submission Warrant), Appearance Approval Report (AAR), etc.

Production Part Approval Process (abbreviated as PPAP)

What does the Production Part Approval Process include

The Production Part Approval Process specifies the general requirements for production part approval, including production and bulk materials.

The purpose of the Production Part Approval Process

The purpose of PPAP is to determine whether the supplier has correctly understood all the requirements of the customer’s engineering design records and specifications, and whether its production process has the potential capability to produce products that meet the customer’s requirements through the specified production process and quality during actual production.

The scope of application of the Production Part Approval Process

PPAP must apply to internal and external supplier sites that provide bulk materials, production materials, production parts, or service parts. For bulk materials, PPAP is not required unless requested by the customer.

The content of the Production Part Approval Process

1. General

For the following situations, the supplier must obtain full approval from the customer’s product approval department.

1. A new part or product (a special part, material, or color that has never previously been supplied to the customer).

2. Correction of a nonconformity on a previously submitted part.

3. A product change resulting from an engineering change to the design record, technical specifications, or materials.

4. Any of the situations required by the PSW.

2. PPAP process requirements

(1) Production parts: products used for PPAP must be taken from an effective production process.

What is meant by an effective production process:

A production run of one to eight hours.

And at least 300 consecutively produced parts, unless otherwise specified by the customer-authorized quality representative.

Production using the same equipment, gauges, processes, materials, and operators as in the production environment.

Parts manufactured by each separate production process — such as the same assembly line and/or work cell, and each cavity of a multi-cavity die, mold, equipment, or tool — must all be measured, and representative parts must be tested.

(2) PPAP requirements

The supplier must meet all specified requirements, such as design records and specifications. For bulk materials, a bulk material requirements checklist is also required.

Any inspection result that does not meet the requirements becomes grounds for rejecting the supplier’s submitted parts, documents, and/or records.

PPAP inspections and tests must be performed by a qualified laboratory (in-house testing requires qualified personnel). Any commercial/independent laboratory used must be an accredited laboratory facility.

When the supplier commissions a commercial laboratory to perform tests, the test results must be submitted using a report format bearing the laboratory’s name, or using a formal laboratory report. The report must clearly state the laboratory name, the test date, and the standards used for testing. A merely general description of conformity for any test result is unacceptable.

Regardless of the submission level of the part, the supplier must keep the corresponding records for each part or group of parts. These records must be listed in, or referenced within, the part’s PPAP documentation, and be available for review at any time.

If a supplier wishes to obtain an exception or to deviate from the original PPAP requirements, it must first obtain approval from the customer’s product approval department. Only then may it submit the relevant supporting documentation along with the approved documents.

1. Design Record

The supplier must have the design records for all products sold to the customer.

Note: Regardless of who is responsible for the design, there will be only one design record for any product, part, or component sold to the customer. The design record may reference other documents and make them part of the design record.

2. Authorized Engineering Change Documents

For all changes not reflected in the design record but already reflected in the product part or tooling, the supplier must obtain authorized engineering change documents.

3. Required Engineering Approval

When specified in the design record, the supplier must have evidence of the customer’s engineering approval.

4. Design Failure Mode and Effects Analysis (Design DFMEA)

If the supplier is responsible for the design, a Design Failure Mode and Effects Analysis (DFMEA) should be conducted.

5. Process Flow Diagram

The supplier must design a process flow diagram in a specified format that clearly depicts the production process steps and sequence and meets the needs and expectations of the specific customer.

6. Process Failure Mode and Effects Analysis (Process PFMEA)

The supplier must conduct the process PFMEA analysis in accordance with IATF 16949 requirements.

7. Dimensional Inspection Results

Provide evidence that dimensional verification has been completed and that its results show conformity to the specified requirements.

Indicate the date and change level of the design record, the complete list of dimensional results, and the approved engineering change documents.

Designate one of the measured parts as the standard sample.

Record the change level, drawing date, supplier name, and part number on the supporting documentation.

The supplier must provide dimensional results for each separate machining process.

8. Material/Performance Test Results Records

The supplier must retain records of the material and/or performance test results specified in the design record or control plan.

(1) Material Test Results

When the design record or control plan specifies chemical, physical, or metallurgical requirements, the supplier must test all parts and product materials. The material test report must indicate:

The design record change level, number, and date of the tested part, and the change level of the test’s technical specifications.

The date the test was performed. The name of the part’s material supplier, and, when requested by the customer, the material supplier code number on the customer-approved supplier list.

(2) Performance Test Results

When the design record or control plan specifies performance or functional requirements, the supplier must test all parts or product materials. The test report must indicate:

The design record change level, number, and date of the tested part, and the change level of the technical specifications the tested part is based on.

Authorized engineering change documents not yet reflected in the design record.

The date the test was performed.

9. Initial Process Study

(1) General

For all special characteristics designated by the customer or the supplier, the acceptability of the initial process capability or performance must be determined before submission.

The supplier must perform a systems analysis to understand the impact of measurement error on the study’s measurement results.

Note 1: This requirement is intended to determine whether the production process is capable of producing products that meet the customer’s requirements. The focus of the initial process analysis is on variables data rather than attributes data.

Note 2: The evaluation index of process capability or performance is agreed upon by both the customer and the supplier. The Cpk and Ppk indices will be introduced below. For certain processes or products, other methods are more applicable and may replace the above methods provided prior customer approval is obtained.

Note 3: The initial process analysis is short-term; it cannot predict the effects produced by changes over time and by changes in personnel, materials, methods, equipment, measurement systems, and the environment. Although it is a short-term analysis, it is also important to use control charts and to collect and analyze the data in sequence.

Note 4: For those characteristics to which the X-Bar and R chart can be applied, the short-term analysis should be performed by sampling from the trial mass-production process, with a minimum sample size of 25 parts and on the basis of at least 100 readings.

(2) Process Capability Index

If applicable, the initial process study should use capability or performance indices to ultimately reflect Cpk — the capability index of a stable process. The estimate of σ is determined based on the within-subgroup variation (R-bar/d2 or S-bar/C4). Ppk — the performance index. The σ value is estimated based on total variation (using the standard deviation of all individual sample data (the root-mean-square equation), “S”) for short-term studies. The purpose of the initial process study is to understand the process tolerance rather than to achieve a specified index value. When historical data is available or there is sufficient initial data to plot a control chart (at least 100 individual samples), sigma can be calculated when the process is stable.

(3) Initial Study Acceptance Criteria

The supplier must use the following acceptance criteria to evaluate the results of the initial process study of a stable process:

Result explanation

Index value > 1.67 The process currently meets the customer’s requirements. After approval, begin production and execute the control plan.

1.33 ≤ index value ≤ 1.67 The process is currently acceptable, but some improvement may still be needed. Contact the customer and review the results. If there is no improvement before the start of mass production, the control plan needs to be changed.

Index value < 1.33 The process currently does not meet the acceptance criteria for customer requirements. Review the analysis results and contact the relevant customer representative to discuss improvement methods or to review the design, etc.

(4) Unstable Process

Depending on the nature of the instability, an unstable process may be unable to meet the customer’s requirements. The supplier must identify and evaluate it and, as far as possible, eliminate the obvious causes of the abnormality before submitting the PPAP. The supplier must notify the customer of the unstable process condition and must provide a corrective action plan before submitting the PPAP.

(5) Unilateral Tolerance or Non-Normal Distribution Processes

For processes with a one-sided tolerance or a non-normal distribution, the supplier must determine the acceptance criteria together with the customer.

(6) Countermeasures When Acceptance Criteria Are Not Met

If the process cannot be improved, the supplier must contact the customer. If the acceptance criteria still cannot be met before the date allowed for PPAP submission, then the supplier must submit to the customer a corrective action plan and a modified control plan that usually includes 100% inspection. Efforts to reduce the tolerance must continue until Ppk or Cpk reaches 1.33 or greater, or until full approval is obtained from the customer.

10. Measurement System Analysis Study

The supplier must perform appropriate measurement system analysis studies on all new gauges, modified gauges, and test equipment used in production, such as gauge repeatability and reproducibility, bias, linearity, and stability studies.

11. Qualified Laboratory Documentation

The supplier must have documentation of the laboratory scope and a statement of conformity to 17025.

12. Control Plan

The supplier must develop a control plan that specifies all process control content. This control plan must comply with IATF 16949 requirements.

13. Part Submission Warrant (PSW)

After satisfactorily completing all required measurements and tests, the supplier must complete the Part Submission Warrant (PSW). A separate PSW must be completed for each part number, unless the customer agrees to another format. If the production part is processed using multiple cavities, molds, tools, dies, or profile dies, or production processes (for example, a production line or work cell), the supplier must perform a complete dimensional evaluation for each part. The supplier must indicate the specific cavity, mold, production line, etc., of the submitted part in the “Mold/Cavity/Production Process” field of the warrant or attachment.

(1) Part Weight (Mass)

The supplier must record the weight of the part to be shipped on the PSW. Unless otherwise specified by the customer, it must always be expressed in kilograms (kg) and accurate to four decimal places (0.0000). The weight must not include shipping protective devices, assembly fixtures, or packaging materials. To determine the part weight, the supplier must randomly select 10 parts, weigh them individually, then calculate and report the average weight. At least one part must be selected for weighing from each cavity number, mold, production line, or process used for production realization.

14. Appearance Approval Report (AAR)

If a part or part family required to be submitted has appearance requirements specified in the design record, a separate Appearance Approval Report (AAR) for that product/part must be completed.

15. Bulk Material Requirements Checklist (applicable only to bulk material PPAP)

For bulk materials, the bulk material requirements checklist must be agreed upon by both the customer and the supplier. All specified requirements must be met, unless specifically marked “No Requirement” (NR) on the checklist.

16. Production Part Samples

The supplier must provide part samples in accordance with the customer’s requirements and the specified submission requirements.

17. Master Sample

The supplier must retain a master sample for the same period as the production part approval records.

18. Checking Aids

If requested by the customer, the supplier must submit any part-specific assembly fixtures or component checking aids at the same time as submitting the PPAP.

The supplier must ensure that all content of the checking aids is consistent with the part’s dimensional requirements. At submission, the supplier must document the engineering design change content incorporated into the checking aids. The supplier must provide preventive maintenance for any checking aids throughout the life of the part.

Measurement system analysis studies must be performed in accordance with the customer’s requirements, such as gauge repeatability and reproducibility, bias, linearity, and stability studies.

19. Customer-Specific Requirements

The supplier must have records of conformity to all applicable customer-specific requirements.

For bulk materials, all customer-specific requirements must be documented on the bulk material requirements checklist.

3. Customer Notification and Submission Requirements

(1) Customer Notification

When the following situations occur, the supplier must notify the customer’s department responsible for product approval. As a result, the customer may decide to require PPAP approval submission.

1. The use of a different construction or material compared to that of the previously approved part or product;

2. The use of new or modified tooling (excluding perishable tooling), dies, molds, patterns, etc., including additional or replacement equipment;

3. Production following the refurbishment or rearrangement of existing tooling and equipment;

4. Production in which the tooling and equipment have been transferred to a different plant or to an additional plant site;

5. A sub-supplier’s change to a part, non-equivalent material, or service (such as heat treatment or plating) that affects the customer’s fit, form, function, durability, or performance requirements;

6. Products produced after the tooling has been reactivated following 12 months or more of inactivity in mass production;

7. Product and process changes involving production parts manufactured internally or by a supplier. These components affect the assembly, fit, form, function, performance, and/or durability of saleable products;

8. Applicable only to bulk materials:

A new source of raw materials with special characteristics provided by a new or existing sub-supplier;

A change in the product’s appearance attributes in the absence of an appearance specification;

A change in parameters within the same process (parameters other than those of the approved product’s PFMEA, including packaging);

A change outside the approved product’s DFMEA (product composition, ingredient levels, etc.).

9. A change in the test/inspection method or adoption of a new technique (not affecting the acceptance criteria).

(2) Customer Submission Requirements

In the following situations, the supplier must submit PPAP approval before the first shipment of product, unless the department responsible for product approval has waived this requirement. Regardless of whether the customer requires formal submission, the supplier must review and update all applicable items in the PPAP documentation as needed to reflect the production process situation.

1. A new part or product (for example, a specific part, material, or color that has never previously been supplied to a customer);

2. Correction of a nonconformity on a previously submitted part;

3. An engineering change concerning the design record, technical specifications, or materials of a production product/part number;

4. For bulk materials only: a new process technology used on the product that the supplier has not previously used.

(3) Situations in Which Customer Notification Is Not Required

In the following situations, customer notification and submission (such as the PSW) are not required. The supplier is responsible for tracking changes and/or improvements and for updating any affected PPAP documentation.

Note: In any case, once the assembly, fit, form, function, performance, and/or durability of the customer’s product is affected, customer notification is required.

1. Changes to components and drawings, manufactured internally or by a sub-supplier, that do not affect the design record of the product supplied to the customer;

2. Tooling moved within the same plant (used for equivalent equipment, with no change to the process flow, and without disassembling the tooling), or equipment moved within the same plant (the same equipment, with no change to the process flow);

3. Changes in equipment (the same process flow with the same basic technology or method);

4. Replacement of the same gauge;

5. Rebalancing the operator’s work content, causing no change to the process flow;

6. Changes that result in a reduction of the PFMEA RPN value (with no change to the process flow);

7. For bulk materials only:

Changes to the approved product DFMEA (formulation range, packaging design);

Changes to the PFMEA (process parameters);

Changes that do not seriously affect the special characteristics (including changing the target value point within the approved specification limits);

Changes to the approved commodity composition (the CAS number does not change within the Chemical Abstracts Service (CAS) series);

A change in the sub-supplier production site producing raw materials that do not involve special characteristics;

A new source for raw materials that do not involve special characteristics;

Tightened customer/sales acceptance tolerance limits.

4. Customer Submission Requirements – Levels of Evidence

(1) Submission Levels

The supplier must submit the items and/or records specified for the level requested by the customer;

Level 1 – Submit the warrant only to the customer (for designated appearance items, an appearance approval report should also be provided);

Level 2 – Submit the warrant, product samples, and limited supporting data to the customer;

Level 3 – Submit the warrant, product samples, and complete supporting data to the customer;

Level 4 – Submit the warrant and other requirements specified by the customer;

Level 5 – Keep the warrant, product samples, and complete supporting data available for review at the supplier’s manufacturing plant.

If the customer’s department responsible for product approval has no other specification, the supplier must use Level 3 as the default level for a full submission. Suppliers that supply bulk materials only must use Level 1 as the default level for submitting all bulk material PPAP documentation, unless otherwise specified by the customer’s department responsible for product approval.

(2) Retention/Submission Requirements Table

Requirement Submission Level

Level 1 Level 2 Level 3 Level 4 Level 5

1. Design record of saleable product R S S R

– For proprietary components/details R R R R

– For all other components/details R S S R

2. Engineering change documents, if any R S S R

3. Customer engineering approval, if required R R S R

4. Design FMEA R R S R

5. Process flow diagram R R S R

6. Process FMEA R R S R

7. Dimensional results R S S R

8. Material and performance test results R S S R

9. Initial process study R R S R

10. Measurement system analysis study R R S R

11. Qualified laboratory documentation R S S R

12. Control plan R R S R

13. Part Submission Warrant (PSW) S S S S R

14. Appearance Approval Report (AAR), if S S S R

applicable

15. Bulk material requirements checklist R R R R

16. Sample product R S S R

17. Master sample R R R R

18. Checking aids R R R R

19. Records of conformity to customer-specific requirements R R S R

S = The supplier must submit to the designated customer product approval department and retain a copy of the record or documentation item at an appropriate location, including the manufacturing location.

R = The supplier must retain it at an appropriate location and make it readily available when the customer representative requests it.

= The supplier must retain it at an appropriate location and submit it to the customer when requested.

5. Part Submission Status

(1) General

The customer must notify the supplier of the result of the submission review. After obtaining production part approval, the supplier must ensure that future production continues to meet the customer’s requirements.

(2) Customer PPAP Status

1. Full approval means that the part meets all of the customer’s technical specifications and requirements. Therefore, the supplier ships parts in the required quantities according to the customer’s planning department’s order schedule.

2. Interim approval permits shipment of material needed for production for a limited time or quantity of parts. The supplier is granted interim approval only in the following situations:

– The root cause of the nonconformity affecting production approval has been clearly identified;

– An interim approval action plan agreed to by the customer has been prepared. Resubmission is required to obtain “full approval.”

For material that has obtained interim approval, if the established improvement action plan is still not met by the use deadline or when the authorized shipping quantity has been reached, it is rejected. If no extension of interim approval has been agreed, further shipment is not permitted.

For bulk parts, the supplier must use the “Bulk Material Interim Approval” form.

3. Rejection means that the samples and documents selected from the production batch for submission do not meet the customer’s requirements. The modified product and documentation must be submitted and approved before mass shipment can take place.

6. Record Retention

Regardless of the level of submission, production part approval records must be retained for the period during which the part is used at the customer’s plant plus one calendar year.

Completing the Part Submission Warrant

Part Information

1. Part Name

2. Customer Part Number: the final part name and number issued by engineering.

3. Safety/Regulatory Item: if the part is noted as a safety/regulatory item on the part drawing, select “Yes”; otherwise, “No.”

4. Engineering Drawing Change Level and Approval Date: state the change level and submission date.

5. Additional Engineering Changes: list all approved engineering changes that are not incorporated in the drawing but are already reflected in the part.

6. Drawing Number: the design record of the customer part number specified for submission.

7. Purchase Order Code: fill in this code based on the purchase order.

8. Part Weight: fill in the actual weight of the part expressed in kilograms, accurate to four decimal places.

9. Checking Aid Code: if an auxiliary tool is used for dimensional inspection, fill in its code.

10. Engineering Change Level and Approval Date.

Supplier Manufacturing Plant Information

11. Supplier Name and Supplier Code: fill in the manufacturing plant site code specified on the purchase order.

12. Supplier Manufacturing Plant Address: fill in the complete address of the location where the part is produced.

Submission Information

13. Submission Type: select the submission type and mark “√” in the corresponding box.

14. Customer Name: fill in the company name and the division or work group.

15. Buyer Name and Buyer Code: fill in the buyer name and code.

16. Application Scope: fill in the model year, vehicle name, or engine, transmission, etc.

Reason for Submission

17. Select the appropriate item, mark “√” in the corresponding box, and add detailed notes in the “Other” field.

Requested Submission Level

18. Indicate the submission level requested by the customer.

Submission Results

19. Select the appropriate item and mark “√” in the corresponding box, including dimensional, material test, performance test, appearance evaluation, and statistical data.

20. Select the appropriate item and mark “√” in the corresponding box. If “No,” it should be explained in the “Explanation” field below.

21. Explanation: provide a detailed explanation of the submission results; when appropriate, additional explanations may be provided in an attachment.

22. After verifying that all results conform to all customer requirements and that all documents required by the customer have been fully prepared, the responsible person at the supplier must sign and approve the content of the declaration, and provide their title, telephone number, and fax number.

For customer use only — do not fill in.

Completing the Appearance Approval Report

1. Part Number: the unified part number.

2. Drawing Number: if different from the part number, fill in the drawing number on which the part is drawn.

3. Application Scope: fill in the code of the vehicle model in which the part is used, or another item name.

4. Part Name: fill in the name of the part as completed according to that part’s drawing.

5. Buyer Code: fill in the code of the buyer specifically purchasing this part.

6. Engineering Change Level Date: the engineering change level and the engineering change date of this submission.

7. Supplier Name: the supplier responsible for the submission (also applicable to sub-suppliers).

8. Manufacturing Location: the location where the part is manufactured and assembled.

9. Supplier Code: the customer-designated code for the location where the supplier produces and assembles the part.

10. Reason for Submission: select the appropriate item to explain the reason for this submission, and mark “√” in the corresponding box.

11. Supplier’s Surface Finishing Information: list all first-surface finishing tools, abrasive sources, abrasive types, textures, and the gloss standard samples used for inspection.

12. Surface Pretreatment Evaluation: completed by all customer representatives (not used by GM).

13. Color Designation: fill in the identification number representing the color, in letters and numbers or numbers.

14. Tristimulus Data: for the submitted part, list the (colorimeter) color number data compared with the customer-approved standard sample.

15. Master Sample Code: fill in the alphanumeric standard identification number.

16. Master Sample Approval Date: fill in the date the master sample was approved.

17. Material Type: indicate the first-surface treatment and the substrate (such as paint/ABS).

18. Material Source: indicate the supplier of the first-surface polishing and the substrate. For example: DOW.

19. Color Evaluation, Color, Hue, Chroma, Metallic Luster, and Brightness: visually assessed by the customer.

20. Color Supply Marking: the subscript or color number under the colored part number.

21. Part Disposition: determined by the customer (approve/reject).

22. Explanation: general remarks by the supplier or customer (optional).

23. Supplier Signature, Telephone Number, and Date: the supplier certifies that the information is accurate and meets all specified requirements.

24. Customer Representative Signature and Date: the customer approval signature.