The Production Part Approval Process (PPAP) was first developed around the nineties inside the American Automotive supply chain. The purpose of the PPAP is to ensure that all quality and production requirements of a product are respected and to verify that the supplier can ensure the pre-established standard even in serial production, thus enhancing trust between suppliers and clients.
The PPAP, like the Advanced Product Quality Planning(APQP), is part of those tools required by the IATF 16949:2016 standard, the most common standard of Quality Management Systems in the automotive industry.
Inoxveneta does not confine this good practice to the automotive industry, instead adopts the PPAP methodology whenever requested by the customer and/or by characteristics of product under approval.
The Production Part Approval Process consists of 19 elements. The supplier is required to provide complete documentation to certify compliance with all design and production requirements.
- Design records – product drawings (including those of components), provided by the customer jointly with the Purchase Order or done by the supplier, in the case the last is in charge of project;
- Authorized change of technical documents (if any) – a document that shows a detailed description of a change not yet included in the drawings but incorporated into the product;
- Engineering approval (if required) – the supplier must give evidence that the customer has approved the activities carried out;
- DFMEA (if the supplier is project responsible) – a copy of the Design Failure mode and Effect Analysis, reviewed and signed off by supplier and customer;
- Process Flow Diagram – a copy of the process flow, clearly indicating all production steps and their sequence, including components;
- PFMEA – a copy of the Process Failure Mode and Effect Analysis in accordance with the requirements of the QS-9000 standard, reviewed and signed by the supplier and the customer. The PFMEA follows the phases of the process flow and identifies any critical issues;
- Control Plan – The control plan encompasses every stage of the production process, up to the inspections on finished goods. It focuses attention on the process critical points and the related monitoring methods. It has to be signed by both the supplier and the customer;
- Measurement System Analysis Studies (MSA) – preventive studies on the adequacy of the measurement systems ( for example: gauges), used in the Control Plan;
- Dimensional results – the supplier must give evidence that it has performed the various tests provided for in the Control Plan and that the results found comply with the specified requirements. A list of every dimension indicated on the approved drawing is made, indicating whether the measurement results are within the margin of tolerance. Dimensional results are usually reported on a minimum number of 6 pieces for each product/process combination.
The supplier must have the dimensional measurements of the products coming from each specific production process. The supplier must indicate the date and modification index of drawing, and any authorized document of modification to the project not yet incorporated in the drawing. One of the parts measured and found to be compliant must be identified as the “Master sample”; - Records of Material/Performance tests – a list of each test performed on the product, the date of execution, the specification and the results, as well as all the certifications of the materials used. The list must be viewed and signed by the technical groups of both customer and supplier;
- Initial Sample Inspection Report – inspection report on the samples of materials used in the realization of the prototype;
- Initial Process studies – statistical control of production processes. The supplier must guarantee a stable variability of the critical process;
- Qualified Laboratory Documentation – copy of all the certifications of the laboratories that performed the tests listed in section 10. As for other elements, the supplier must comply with QS-9000 standard;
- Appearance Approval Report – copy of each component’s AAI (Appearance Approval Inspection) for which submission is required;
- Sample Production Parts – a sample of the first production batch. In the PPAP documentation there is an image of the sample and it is specified where the sample will be stored (customer or supplier);
- Master Sample – is the sample jointly approved by the customer and the supplier and which is also used to train operators regarding various control activities, including inspections that require subjective assessments by the operator;
- Checking Aids – if necessary, the supplier will present the specific tools and gauges for the required inspections. The supplier guarantees that the control tools are compliant for the dimensional measurements that must be carried out. In the event of drawing changes, the supplier must check whether changes to control tools are required and, if necessary, adapt tools and gauges accordingly. The supplier must provide for the preventive maintenance of each control tool throughout the life of the part in order to avoid degradation that could compromise the validity of the tools;
- Customer–specific requirements – each customer may have specific requirements to be in the PPAP package;
- Part Submission Warrant (PSW) – summary form of the entire PPAP package. The supplier must verify that all measurements and test results show compliance with the customer’s requirements and that all required documentation is available;
There are five distinct levels of the PPAP that determine the amount of documentation that supplier is required to deliver to the customer:
Level 1: Part Submission Warrant (PSW) only submitted to the customer.
Level 2: PSW with product samples and limited supporting data.
Level 3: PSW with product samples and complete supporting data.
Level 4: PSW and other requirements as defined by the customer.
Level 5: PSW with product samples and complete supporting data available for review at the supplier’s manufacturing location. Complete documentation.
Level 3 is used as the default level by all suppliers (except raw materials) unless otherwise specified by the customer.
Following the presentation of the documentation and sampling, the PPAP process can have three types of outcome:
Full approval – processes and product meet all customer requirements and specifications.
Interim approval – the approval is limited to a small quantity to be delivered within a specified period of time.
Rejected – the sampling and documentation do not meet the customer’s requirements.
