Supplier Quality Assurance,

For those new to the concept of Supplier Quality Assurance, we are going to break down in real terms where this is applied. Do you own a mobile phone, a car, or a computer? Each one of these products is typically manufactured (assembled) by an Overall Equipment Manufacturer (OEM). But do they also combine all the components that to make the final product? The answer, to being cost-competitive, is no. In today’s fast-paced, high-quality, low-cost world it would be economically unviable for an OEM to manufacture all the parts. This is because consumers want cars, phones, and computers to be affordable and wages at the point of assembly are higher than that of a Low-Cost Country. 

Supplier Quality Assurance – When is it applied?

Supplier Quality Assurance, in the context of Automotive manufacturing, is applied from the New Product Development Phases in alignment with Advanced Product Quality Planning (APQP), Supplier Sourcing and Approval, Crisis and Nonconformity Management.

Many Automotive OEMs require their suppliers to cascade their Customer Specific Requirements throughout the Supply Chain from Tier 1, 2, 3, 4, … to the Nth level. The idea of Supplier Quality Assurance is such that the Supplier assures the product before it is sent to the Customer. If the Supplier is the Tier 2, the Customer is the Tier 1 and so on.

Quality Control relies on the next stage in the process to capture any issues and feedback to the originator of the problem. Quality Assurance stops the issue at the point of manufacture. I want you to think “Never receive any defects…never make any defects…never pass any defects”.

Supplier Quality,

Supplier Quality Assurance and Concern Management

Let’s start with the fundamentals of how this term is defined:

Supplier Quality Assurance professionals (Inspectors,  Coordinators, Technicians and Engineers) manage concerns raised with purchased parts that are manufactured by a Supplier.  They will typically gather Problem Definition information from the Originator, determine probable liability i.e. a manufacturing defect that was caused by the Supplier and kick start Corrective Action – Preventative Action (CAPA) to ensure recurrence prevention.

Supplier Quality Assurance and New Product Development

New Product Development in the context of this article is based on AIAG – Advanced Product Quality Planning.

Supplier Quality Assurance Engineering typically becomes involved with New Product Development when a design has achieved Proof of Concept and is ready to be in an “Off-Tool” condition.


The Door Handle Cap at Proof of Concept is 3D printed. But the Off-Tool part is made from an injection mould in the production site location.

The Supplier Quality Assurance Engineer will work with the Supplier to develop the product into a saleable condition.

Supplier Quality Assurance and Production Part Approval

The Production Part Approval Process (PPAP) is another core tool important to cooperate with Supplier. It is a key set of activities which are used to capture objective-based evidence throughout the product development as the product matures into a saleable condition (Off-Tool/Off-Process).

PPAP consists of approximately 18 elements which depend on the Customer’s specific requirements for submission. The documents are shown below:

  • Design record.
  • Engineering Change Documents.
  • Customer Engineering Approval.
  • Design FMEA.
  • Process Flow Diagrams.
  • Process FMEA.
  • Control Plan.
  • Measurement System Analysis.
  • Dimensional Results.
  • Material, Performance Test Results.
  • Initial Process Studies.
  • Qualified Laboratory Documentation.
  • Appearance Approval Report.
  • Sample Product.
  • Master Sample.
  • Checking Aids.
  • Records of Compliance with Customer Specific Requirements.
  • Part Submission Warrant.

Note: Each customer may have their own requirements and exceptions to the PPAP requirements.

Supplier Quality Assurance in IATF 16949

Supplier Quality Assurance activities are intertwined with the Automotive Quality Management System Standard IATF 16949. Actually this concept has a lot of requirements. They are collected in chapter 8.4 called “Control of Externally Provided Processes, Products and Services”.

As we touched in this article Advanced Product Quality Planning (APQP), Supplier Sourcing and Approval, Crisis and Nonconformity Management let us emphasize for you the applicable requirements also beyond chapter 8.4 (some of them are also well defined in ISO 9001 as a starting point): Design and development planning – supplemental

The organization shall ensure that design and development planning includes all affected stakeholders within the organization and, as appropriate, its supply chain. Examples of using such a multidisciplinary approach include (…) Project management (APQP or VDA-RGA). (…). Product Approval Process

The organization shall (…) approve externally provided products and services (…) prior to submission of their part approval to the customer (…).

8.4 Control of externally provided processes, products and services.

Extremally important chapter! All sections starting from ISO 9001 point 8.4.1 to in IATF 16949 apply to Supplier Quality Assurance concept. Let ‘s just put an emphasis on:

8.4.1    General

The organization shall ensure that externally provided processes, products and services conform to requirements, (…) the controls to be applied to externally provided processes, products and services when:

  1. products and services from external providers are intended for incorporation into the organization’s own products and services;
  2. products and services are provided directly to the customer(s) by external providers on behalf of the organization;
  3. a process, or part of a process, is provided by an external provider as a result of a decision by the organization.

(…) determine and apply criteria for the evaluation, selection, monitoring of performance, and re-evaluation of external providers, based on their ability to provide processes or products and services in accordance with requirements. The organization shall retain documented information of these activities and any necessary actions arising from the evaluations. Control of changes – supplemental

The organization shall have a documented process to control and react to changes that impact product realization. The effects of any change, including those changes caused by the  (…) supplier, shall be assessed.

8.6.4    Verification and acceptance of conformity of externally provided products and services

The organization shall have a process to ensure the quality of externally provided processes, products, and services utilizing one or more of the following methods:

  1. receipt and evaluation of statistical data provided by the supplier to the organization;
  2. receiving inspection and/or testing, such as sampling based on performance;
  3. second-party or third-party assessments or audits of supplier sites when coupled with records of acceptable delivered product conformance to requirements;
  4. part evaluation by a designated laboratory;
  5. another method agreed with the customer. 

8.6.5    Statutory and regulatory conformity

Prior to release of externally provided products into its production flow, the organization shall confirm and be able to provide evidence that externally provided processes, products, and services conform to the latest applicable statutory, regulatory, and other requirements in the countries where they are manufactured and in the customer-identified countries of destination, if provided.

9.3.2    Management Review Inputs

The management review shall be planned and carried out taking into consideration: (…)          information on the performance and effectiveness of the quality management system, including trends in (…) the performance of external providers;

10.2     Nonconformity and Corrective Action

Any nonconformity which is also connected to the Quality Assurance at Supplier is relevant to these requirements in ISO 9001:

10.2.1  Reaction to nonconformities

When a nonconformity occurs (…) the organization shall:

  1. react to the nonconformity (…)
  2. evaluate the need for action to eliminate the cause(s) of the nonconformity(…);
  3. implement any action needed;
  4. review the effectiveness of any corrective action taken;
  5. update risks and opportunities determined during planning, if necessary;
  6. make changes to the quality management system, if necessary.

Let’s sum up!

Approximately 70% of a vehicle’s Bill of Materials, components which come together to make the final assembly, are manufactured by Suppliers. It’s clear to see that Supplier Quality Assurance is a critical function within Automotive. Arguably all OEMs who do not make all the components in-house. Supplier Quality Assurance is a collaboration, a partnership working towards Safe products, complying with applicable regulations, and enhancing the final customer experience to maintain brand loyalty and image.

This article is a shoutout to all those who work in this challenging role and their dedication to Quality Assurance.

Do you want to know more?

We invite you to the ISO 9001 and IATF 16949 training or IATF 16949 self-learning online course organized by Qualitywise, where you will learn in detail all the requirements for the quality management system. Ask about the date.


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Thank you for your presence.

Agata Lewkowska Ph.D.

Christopher Scott

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For people who want to know more:

Knowledge must have a solid foundation in order to avoid information noise. Therefore, the article was based on the following literature:

IATF 16949: 2016 Requirements for quality management systems in serial production and the production of spare parts in the automotive industry, 1st edition, 2016

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