You’re about to close a delivery. The supplier confirms the package is complete. Your customer expects a clean approval. And suddenly… rejection.

Once again, PPAP becomes a bottleneck. And not because of technical complexity, but due to mistakes that could have been prevented from the first email.

It doesn’t matter how many projects you’ve handled—when a PPAP fails, what shakes is the trust you’ve built over weeks (or months).

The good news? These mistakes are avoidable. Even better? Avoiding them doesn’t require more resources—just a better understanding of how the game is played.

Why Do PPAPs Really Fail?

SUBSCRIBE

SHARE '

Follow us!

Why Does PPAP Keep Failing? What No One Says but Everyone’s Lived Through

You might be interested in these articles:

Approved PPAP: Luck or strategy?

When a PPAP is approved without comments, there’s a reason behind it. It wasn’t luck.

It was attention to detail. It was consistency between planning and execution.

It was ongoing dialogue with the customer—not silence.

And that doesn’t just reduce your workload. It reinforces something far more valuable: the perception that the supplier understands their process, knows their risks, and stays ahead of problems.

At PTI QCS, we work to ensure PPAP is no longer a blind spot in your project. From the start of APQP, our experts support your team with mirror document reviews, data-driven statistical validation, and alignment between what’s submitted and what’s happening on the floor.

All this is integrated into our quality inspection, rework, launch support, yard management, and supply chain services. Because a successful PPAP is the outcome of well-connected processes. Contact us at janava@ptiqcs.com for Mexico and at sales@ptiqcs.com for the U.S. or Canada.

1. Assuming the submission level… without confirming

Submitting a Level 3 when the customer requested a Level 5 isn’t just an oversight—it’s starting the game with a score against you.

Each PPAP level corresponds to a specific context: criticality, risk, supplier history. Not all parts require the same approach, and making assumptions is one of the most common mistakes.

Pro tip: Document with the customer what level applies to each component type early in APQP. Improvisation never saves time.

2. Weak APQP = Fragile PPAP

A solid PPAP isn’t built overnight. It’s the natural result of a well-executed APQP.

If your DFMEA skipped realistic scenarios, if the control plan doesn’t reflect what’s happening on the shop floor, or if human risk factors weren’t considered—no PPAP package will survive the audit.

3. Inconsistent documentation

A control plan that doesn’t match the FMEA. A flowchart copied from a different project. Dimensional results with incorrect tolerances.

These aren’t technical errors—they’re operational. But they carry the same weight as a major nonconformance.

Quick fix: Implement cross-check mirror reviews. Every document must align. One inconsistency breaks the entire chain.

4. Bare-minimum statistical analysis

Submitting an MSA without operator repeatability, using only 15 parts for a capability study that required 30, or copying an R&R from another process... customers notice. And they question it.

Because beyond the numbers, what’s at stake is your real understanding of how the process behaves. .

Recommendation: Make sure your studies reflect actual operating conditions. A high Cp in theory means nothing without real-world backing.

5. Silent communication

Waiting until the PPAP submission to talk to your customer is like driving on autopilot and only asking if you arrived at the end.

Many rejections could be avoided with a timely call—to validate formats, align expectations, or clarify special requirements.

Suggestion: Schedule a "Pre-PPAP Check-In" with your customer. Not to present progress, but to align expectations. A five-minute conversation can save you weeks of back-and-forth.

How can PTI QCS help ?