IATF 16949 Injection Molding and What It Means for Your Automotive Parts

If you are adding an injection molder to your supply base for automotive parts, the IATF 16949 certificate is usually the first thing your own customer will ask about, and the documents behind it decide how smoothly your part reaches series production. We are Aplus Molds & Plastics (AMP), a plastic injection molding manufacturer with plants in Tainan, Taiwan, and Samut Prakan, Thailand. We make interior and exterior automotive plastic components for Tier 1 and Tier 2 suppliers, and both of our plants are certified to IATF 16949. In this article we explain what IATF 16949 injection molding involves in practice, which documents you should expect with an approved part, and what is worth checking on the certificate itself.

IATF 16949 is the quality management standard that vehicle makers require across their supply chains. For an injection molder, it adds four controls to ISO 9001: a control plan for each part, formal approval of the first production parts, traceability back to production records, and notice to the customer before any change. For you, this means documented evidence that your part is made under control.

What Does IATF 16949 Require From an Injection Molder?

If your purchasing documents ask for IATF 16949, it helps to know how it differs from the ISO 9001 certificate that most molders already hold. IATF 16949:2016 is published by the International Automotive Task Force, and ISO describes it as a supplement used together with ISO 9001:2015, not as a stand-alone standard. It replaced ISO/TS 16949 (the earlier automotive specification), which some older purchasing documents still name. ISO 9001 asks a plant to control its processes, while IATF 16949 asks the plant to show, for each part number, how that control is planned, measured and recorded. In practice, you should expect to see the records for your own part, and not only a description of the quality system.

Control plans for each molded part

Each automotive part we mold has a control plan. This is a document listing every characteristic that matters on the part, how it is measured, how often, and what the operator must do if a result falls outside its limit. On a molded part, the list covers dimensions, appearance and part weight. It also covers process settings such as barrel temperature, injection pressure and holding time, because a drift in these settings tends to show up in the part shortly afterwards. We record these settings throughout each run, as we describe in our article on real-time process monitoring.

The control plan is built from a process FMEA, a structured review of what could go wrong at each step of production and how likely it is to reach you. We revise the two documents together whenever the process changes, so if you ask to see them during an audit, you’ll find that they agree with each other.

Customer-specific requirements from vehicle makers

If your part goes into a particular vehicle maker’s supply chain, that maker’s own rules will apply on top of the standard. The IATF publishes these customer-specific requirements for ten vehicle makers and groups, with two more in preparation, and a Tier 1 supplier normally passes the relevant ones down to its own suppliers. They can change the approval format, the records to be kept and how long those records must be retained. If you tell us at the quotation stage which customer-specific requirements apply to your part, we’ll build the control plan and approval documents around them from the start, so that nothing needs to be reworked once the mold is made.

Which Documents Come With an Approved Automotive Part?

Before series production starts, an IATF 16949 molder sends you a PPAP submission, the evidence that parts made on the production mold, at the production rate, meet your drawing. The requirements are set out in the PPAP manual published by the Automotive Industry Action Group, which lists eighteen possible elements. These range from dimensional results and material certificates to the control plan and the Part Submission Warrant, the summary document that the supplier signs. If you supply German vehicle makers, you may be asked for PPF instead, the equivalent procedure set out in VDA Volume 2.

PPAP submission levels

You decide how much of the package is actually sent to you. The AIAG manual sets five levels:

Level	What the supplier submits to the customer
1	The Part Submission Warrant only, with an appearance approval report where one applies
2	The warrant with sample parts and a limited set of supporting data
3	The warrant with sample parts and the complete supporting data
4	The warrant and other requirements defined by the customer
5	The warrant with sample parts and complete supporting data, reviewed at the supplier’s plant

Level 3 is the default in the AIAG manual and the level most automotive buyers ask for. In our automotive programs, PPAP submissions, control plans, process capability studies and first article documentation are standard, and we agree the level and format with you at the start of the project. We would suggest settling the level when you request a quotation. A Level 3 package for a large exterior part with many measured features takes a good deal more work than a Level 1 warrant, and agreeing it early means that work is already in the program plan and won’t hold up your approval date.

Process capability on molded dimensions

Your customer will want to know that a dimension stays inside its tolerance throughout production, and not only on the sample parts. Process capability is the measure of this, and it is usually reported as Ppk for the initial study (based on the first production run) and as Cpk once production is running. The AIAG manual treats an initial value above 1.67 as acceptable, which on a centered process means the spread of measurements uses no more than about 60 percent of the tolerance.

On molded parts, the dimensions that find this hardest are usually those affected by shrinkage and warpage over a long distance, such as the overall length of a bumper or the flatness of a door trim panel. We discuss these in our article on large-part injection molding for automotive parts. If you mark the special characteristics on your drawing before the mold is designed, we can plan the gating and cooling around them, which is usually much easier than correcting a mold after the first trial.

What Happens When a Material, Process or Plant Changes?

Once your parts are in regular supply, two requirements of IATF 16949 protect you most: traceability, and the control of changes to an approved part.

Traceability from shipped parts to production records

If a problem appears on your assembly line, the first thing you’ll want to know is how many parts are affected. The standard requires a molder to trace shipped parts back to their production records, which on molded parts normally means the resin lot, the mold, the machine and the production date. With that record, containment can be limited to the affected lots, which can save you from sorting all of your stock. The checks we make on the resin and the parts along the way are covered in our article on IQC, IPQC and FQC inspection points.

Changes of material, process or plant

Under IATF 16949, a molder may not change the material, the process or the production location of an approved part without telling you first. The AIAG manual also requires a new PPAP submission for many of these changes, including a move of production to a different plant.

This matters if you plan to buy from both of our plants. Our Taiwan and Thailand plants hold separate IATF 16949 certificates, and a part approved in Tainan is approved for Tainan. If you want the same part produced in Samut Prakan, we handle it as a change that needs your approval and a new submission from the Thai plant, so that the move is documented in the same way as the original approval. If a second source is part of your sourcing strategy, it’s worth allowing time for this second approval in your plan from the beginning.

What to Check on an IATF 16949 Certificate

An IATF 16949 certificate covers only the plant and the scope written on it. Many buyers confirm that a certificate exists without reading those details, so it is worth having a look at the certificate itself. The checks below take a few minutes, and we have noted how each one applies to AMP.

• The plant named on the certificate. Certificates are issued for a specific site. Our Tainan and Samut Prakan plants each hold their own certificate, both issued by TÜV NORD CERT.
• The validity dates. A certificate runs for three years, with surveillance audits at least once a year in between. Both of our certificates are current, and their registration numbers are listed on our certifications page.
• The scope. Our certificates cover production, with product design (section 8.3 of the standard) excluded. This is the usual arrangement for a molder producing parts to your drawing, since you or your customer remain responsible for the part design, while we are responsible for producing it consistently to that design.
• The certification body. Only certification bodies under contract with the IATF may issue IATF 16949 certificates, and the IATF’s online customer portal lets you confirm that a certificate is genuine.

If you need copies of our certificates for your supplier file, we include them in our supplier qualification package once a non-disclosure agreement is in place.

A current certificate also tells you something about the work a plant is doing. As TÜV Rheinland’s summary of the certification rules notes, the certification audit has to include the automotive customers the site actually serves, so a certificate kept through successive audit cycles reflects automotive production running throughout that time. AMP was first certified to IATF 16949 in 2018. Our automotive parts range from blower assemblies and defroster nozzles to bumpers and radiator grilles, molded on presses of up to 3,200 tons at our Taiwan plant, and we export them to the United States, Canada, Germany, South Korea and Japan. They go to Tier 1 and Tier 2 suppliers in the supply chains of vehicle makers including Toyota, Honda, Nissan, Hyundai, BMW, Mercedes-Benz, Volkswagen and Ford. Our quality page describes the inspection and testing behind this.

If you send us your drawing and annual volume, together with the PPAP level and any customer-specific requirements that apply, our team in Taiwan will reply with a quotation, a manufacturability review and a view on which of our two plants suits the part. We’ll also list the approval documents we will provide, so that you can check them against your own customer’s requirements before you place an order. Please send your files through our inquiry form.