Is PPAP Mandatory for Tier-2 Suppliers, or Only for Tier-1?

By Yamm Labs · Updated September 2026 · 6 min read

A forging shop in Faridabad supplies steering knuckle blanks to a Tier-1 in Manesar. It has never dealt with a car maker directly and has never signed a Part Submission Warrant. Then the Tier-1 wins a new programme, and a mail arrives from its supplier quality engineer: “Please submit PPAP Level 3 for the new blank before our own submission to the OEM. Dimensional results, material certificates, control plan, PSW.” The owner calls his quality head and asks the question this page answers. We only supply the Tier-1. Is PPAP our job too?

Why does PPAP reach Tier-2 suppliers that never deal with the OEM?

PPAP comes from the AIAG Production Part Approval Process manual, an industry standard. No government body in India enforces it. It becomes binding when a customer writes it into a purchase order or a supplier quality manual, and that is exactly how it travels down the chain.

The link that makes it flow is IATF 16949, the automotive quality management standard Tier-1 plants are commonly certified to. It requires the certified organisation to approve the products and services it buys from outside before it submits its own part approval to its customer. A Tier-1 cannot warrant a steering knuckle to the OEM if it has not approved the blank inside it. So the Tier-1 needs evidence from its Tier-2, and the common format for that evidence is a PPAP. Wider guidance on PPAP scope says the same: approval may be required for every component and material incorporated in the finished product, and for components processed by outside subcontractors such as platers and heat treaters.

The obligation therefore sits with the Tier-2 through a contract, not a statute. For the plant it makes no difference. If the purchase order or the Tier-1’s manual asks for PPAP, the part usually cannot ship into series production until the PPAP is approved or given an interim approval.

What does the Tier-1 usually ask a Tier-2 to submit?

The level and element list are the Tier-1’s call, set in its supplier manual or the purchase order. The AIAG manual defines five submission levels, and Level 3 is the default when the customer does not name another. What changes by tier is mostly how much is sent, not how much is done.

This question and dozens of related ones are covered briefly on the PPAP documentation FAQ. This page holds the full answer for the Tier-2 case.

The timeline decision: a Tier-2 PPAP is due before the Tier-1’s

This is the design decision the rule forces, and it is easy for a Tier-2 plant to miss. Because the Tier-1 has to approve bought-in parts before it submits to the OEM, the Tier-2’s pack is due first. If the OEM’s deadline for the Tier-1 is week twelve, the Tier-1 needs the Tier-2’s approved pack some weeks earlier so it has time to review it, reject it once and still meet its own date.

• Ask for the Tier-1’s date, not the OEM’s. The date in your purchase order is the one that governs your pack. Work backwards from it.
• Get the Tier-1’s supplier manual before drafting. It names the level, the forms, the portal or mail route and any extra elements. A pack built to the generic manual comes back.
• Mark pass-through characteristics early. AIAG’s sub-tier supplier management guideline, CQI-19, points Tier-1s at characteristics that pass through the Tier-2 part into the final product. Expect the Tier-1 to ask for the most evidence on exactly those.
• Keep your own sub-suppliers in the plan. If your raw material mill, plater or heat treater changes, the Tier-1 will expect to hear about it, and it may ask for their evidence too.

A Tier-2 PPAP is not optional just because the OEM never sees it; it is the first document in the Tier-1’s own approval.

Who prepares the Tier-2 pack, and who signs it?

The Tier-2 owns its PPAP. Its responsible official signs the Part Submission Warrant, and nobody else can. A consultant or documentation desk can draft the warrant, but the signature block stays blank until the plant’s own official has reviewed the pack.

The work splits by who holds the information. Documents written from the drawing, the route and the customer’s requirements can be prepared outside the plant: the ballooned print, the process flow diagram, the PFMEA, the control plan, process sheets, MSA formats and capability study templates. Evidence that exists only once parts are made stays inside the plant: the trial run, physical measurement, capability studies, Gage R&R trials, laboratory testing and samples. The AI PPAP generator page explains how the drafting half can be automated without touching the measurement half.

A Tier-2 plant whose small quality team also handles inspection and customer complaints faces one more choice. The decision is whether to draft in house or hand the documentation core to a desk. Yamm Labs’ PPAP Desk works with Tier-1 and Tier-2 component suppliers from Gurugram on that split. The two-part pilot is free, with no retainer.

A step-by-step PPAP checklist for Tier-2 suppliers

The request usually arrives as a short mail with a long attachment. The steps below turn it into a plan the plant can run. They follow the order in which information becomes available, so nothing waits on something that has not happened yet.

1. Collect the governing documents. The purchase order, the drawing at its current revision, the Tier-1’s supplier quality manual and any customer-specific forms. These decide everything that follows.
2. Confirm the level, the element list and the date. Write them down and send them back to the Tier-1’s supplier quality engineer for confirmation. A one-line reply now saves a rejected pack later.
3. Mark the special and pass-through characteristics. Balloon the drawing and flag every characteristic the Tier-1 or the OEM has marked, and every one that passes into the final product.
4. Draft the planning documents. Process flow, PFMEA and control plan, in that order, on the Tier-1’s formats where it has them.
5. Plan the trial run. Agree the quantity, the machines, the operators and the gauges. The run has to reflect series production, not a toolroom build.
6. Measure, test and study. Dimensional results, material certificates or test reports, measurement system analysis and capability studies, each against the characteristics marked in step three.
7. Assemble and review the pack. Check every element against the confirmed list before the responsible official signs the Part Submission Warrant.
8. Submit and record the outcome. Keep the approval, interim approval or rejection note with the pack, along with the date and the revision it applies to.

A worked example: the forging shop’s first Level 3 pack

Go back to the Faridabad forging shop. The Tier-1’s mail named the level and four items: dimensional results, material certificates, the control plan and the PSW. The first decision is to ask for the Tier-1’s supplier manual, because a Level 3 pack under that manual will almost certainly include more than the four items the mail mentioned.

The second decision is the date. The mail gives the Tier-1’s own submission to the OEM, not the date the shop’s pack is due. The owner asks, and plans backwards from the answer: time for the Tier-1 to review, time for one rejection and resubmission, then the shop’s own trial run and measurement before that.

The third decision is the split of work. The quality head keeps the trial run, the dimensional layout, the material certificates from the steel supplier and the capability studies on the characteristics the Tier-1 marked. The drafting of the process flow, PFMEA and control plan can run in parallel, inside or outside the plant. The owner signs the warrant only after the quality head has reviewed the complete pack against the manual.

These steps are illustrative. The Tier-1’s manual and purchase order always decide the actual level, elements and dates.

Common mistakes in a first Tier-2 PPAP

• Working to the OEM’s date. The Tier-2 pack is due before the Tier-1’s own submission. Starting from the OEM date leaves no room for a rejection.
• Using generic templates. A pack on generic forms is often returned for reformatting even when the content is right. Use the Tier-1’s forms from the start.
• Sending only what was asked. A Level 1 or Level 2 request still needs every element completed and kept on file, because the Tier-1 can ask for it later.
• Measuring from a toolroom build. Capability studies from a hand-finished sample do not describe series production. The trial run has to use production conditions.
• Forgetting sub-suppliers. Material certificates, heat treatment and coating records come from your own suppliers. Ask for them early, on the format the Tier-1 accepts.
• Changing something quietly. A new steel source or a different heat treater after approval usually needs notification and resubmission. Tell the Tier-1 before the change.

How to brief a documentation desk or consultant

If the plant hands the drafting to an outside desk, the brief decides the quality of the first draft. Send the drawing at its current revision, the purchase order, the Tier-1’s supplier manual and forms, the confirmed level and element list, and the date the Tier-1 needs the pack.

Add the plant’s own knowledge: the process route with each operation and machine, the gauges and measuring equipment available, existing control plans for similar parts, and the names of the sub-suppliers for material, heat treatment and coating. The more of this arrives on day one, the fewer questions come back.

Be clear about the split. The desk drafts documents written from the drawing, the route and the customer’s requirements. The plant runs the trial, takes the measurements, runs the studies and signs the warrant. Agree who reviews each draft inside the plant, and by when, so the drafts do not wait in an inbox while the date moves closer.

People also ask

Can a Tier-2 refuse to submit PPAP if its contract does not mention it?

If neither the purchase order nor the Tier-1’s supplier manual asks for PPAP, there is no obligation to submit one. In practice a Tier-1 certified to IATF 16949 has good reason to write it in, because it must approve bought-in parts before its own submission. Read the manual attached to the purchase order before you quote.

Is a Tier-2 PPAP lighter than a Tier-1 PPAP?

It can be. The Tier-1 decides the submission level and the elements, and for a low-risk part it may accept a warrant with limited data. The work behind the pack is the same, so complete every element even when you send fewer.

Do Tier-3 suppliers need PPAP too?

Only if their customer asks for it, which is usually the Tier-2. The same logic flows down: a supplier that must approve bought-in material before its own submission may ask its own suppliers for evidence, in whatever form it specifies.

Do Tier-2 suppliers need IATF 16949 certification to submit PPAP?

No. PPAP is an approval for a part, not a certificate for a plant, and a Tier-2 can submit one without holding IATF 16949 certification. The Tier-1’s supplier manual states whether it expects its suppliers to run a certified quality system, so read that requirement alongside the PPAP request and plan for both if both apply.

What is an interim approval?

An interim approval lets a supplier ship parts for a limited time or quantity while some PPAP items are still open. The customer sets the conditions and the deadline for closing the open items. It is a bridge, not an approval, so the plant should treat the open items as the first priority and keep the interim terms with the pack.

Who at a Tier-2 plant should sign the Part Submission Warrant?

An authorised person at the supplier, often the quality head or the plant head, who can confirm that the pack reflects parts made under production conditions. The Tier-1’s manual may say more about who can sign. A consultant or documentation desk can prepare the warrant but must never sign it on the plant’s behalf.

How long does a Tier-2 PPAP take to prepare?

It depends on the level, the number of characteristics and when the trial run can happen. Drafting the planning documents can run in parallel with tooling and trial planning, while measurement and capability studies can only start once production-representative parts exist. Start from the Tier-1’s due date and work backwards, leaving time for one rejection.