Why PPAP Is the Key to Scaling Additive Manufacturing

While highly responsive, additive manufacturing carries more variability than traditional methods like injection molding or machining. Without discipline, that variability can create significant risk.

DI Labs has spent years supporting mission-critical industries like medical device and defense, where precision and reliability cannot be compromised. Our work ranges from accelerating clinical builds to developing full-scale volume production programs. Through it all, one lesson is clear: additive manufacturing does not scale without a disciplined approach to risk. Our Production Part Approval Process (PPAP) is the risk management tool we use to align with clients on what matters most, prove results with iterative samples, refine QC priorities, and clarify the important balance between timeline and budget.

This guide distills a recent Solutionology Stories Podcast episode where hosts Carl and Brian Douglass, Co-founders of DI Labs, offer guidance designed for product developers, managers, and innovators who are building a path from concept to commercialization.

1. The double-edged sword of additive

Additive manufacturing can move fast, which is a strength, but that same speed also creates risk. When teams rush forward, they can miss critical aspects of the part, skip dimensional checks, or underestimate the variability that is always present in additive processes. Those gaps can show up later as scrap, yield loss, parts that do not perform as intended, and lost time.

• Speed increases the chance of missing critical dimensional details
• Direct-to-build approaches can bypass the alignment step on what matters most
• Inherent variability, if unmanaged, creates yield loss and scrap

“Additive manufacturing is a double-edged sword. One edge is speed and innovation. The other edge is risk.” — Carl Douglass

2. What PPAP really does

PPAP has different flavors, but the goal is always the same: alignment with clients and becoming familiar with the products before scaling. By running samples, checking dimensions, and experiencing the part together, we can collaboratively establish the right risk management controls for the process.

• Clarifies what success and failure look like for the client
• Identifies and agrees on which dimensions are critical
• Uses iterative runs to validate results before releasing to scaled production

“We want to become familiar and experts at the products that we are making, before we scale into thousands of parts.” — Brian Douglass

3. Practical risk management in AM

Every program faces different constraints. Some are driven by fixed deadlines like clinical trials, where there is no second chance. Others are driven by cost or by the need to make progress quickly. PPAP provides an adaptable structure allowing for customization, sometimes accelerating steps, sometimes overproducing critical parts, and sometimes taking more time to validate.

• Clinical programs often require accelerated PPAP or intentional overproduction
• Skipping PPAP usually results in scrap and wasted resources
• Programs with more time benefit from iterative sampling and dimensional alignment

“If you do not have time to do it right the first time, how are you going to have time to do it right the second time?” — Carl Douglass

4. The ROI of doing it right

Spending time and money on PPAP up front may feel like a cost, but it prevents much larger losses later. Even a modest validation step can save multiples in avoided scrap, rework, and program delays. The math is straightforward: PPAP returns far more than it costs.

• A $5,000 PPAP run can prevent $45,000 in wasted parts and rework
• ROI often ranges from 10 to 100 times the investment
• Early validation avoids costly resets and keeps programs on track

“An investment of $500 or $5,000 on the front end can return 10 to 100 times that amount on the back end.” — Carl Douglass

5. Collaboration is non-negotiable

PPAP only works when both sides are engaged. Without an active feedback loop, even small variables like geometry orientation, build location, or calibration differences across machines can create major variation. DI Labs drives repeatability by controlling what we can and making those variables visible to clients for maximum alignment.

• Alignment on critical dimensions and tolerances is essential
• Orientation, build design, and processing parameters need to stay consistent
• Calibration differences across machines must be understood and managed

“Without a bidirectional feedback loop, where expectations are set, understood, and measured against, you do not converge on a solution intentionally. You just get whatever comes out.” — Brian Douglass

6. Tailor PPAP to the program

There is no one-size approach to PPAP. The process details are driven by the manufacturing method, number of parts, complexity of the product features, and application requirements. It can range from simple visual checks to extensive dimensional validation and strict repeatability controls.

• Ergonomic or low-risk parts may only need surface checks
• Dimensional-critical assemblies require full validation and iteration
• High-volume programs may require locked orientations and consistent builds designs

The goal is always the same: scale the PPAP process to fit the program, balancing time, cost, and risk in a way that creates confidence.

Final thoughts

PPAP in additive is not about slowing innovation – it's about scaling it with confidence. The practical move is simple: align early, invest a little up front, and avoid the expensive, unnecessary rework. DI Labs sees its role as guiding teams through that journey, helping them anticipate risks, control variables, and deliver parts with confidence at scale.

DI Labs PAP Process: https://dilabs.cc/production/

DI Labs specializes in additive manufacturing for volume production in mission-critical industries like medical devices, defense, and consumer products. With over a decade of engineering and product development experience, DI Labs delivers repeatable quality, reduces risk, and helps teams balance time, cost, and regulatory requirements as they scale additive into dependable supply chains. Learn more at www.dilab.cc