3D printing (Additive Manufacturing = AM) has changed the way manufacturers think about production, letting businesses create complex and customized parts with ease and move towards on-demand production. But finding the right parts for additive manufacturing isn’t always straightforward, especially for companies that are new to the technology. The quality of the parts chosen for printing can make or break the outcome. This article gives a 3-step guide from a supply chain perspective that helps companies through the selection process, from an initial assessment to technical validation and a full TCO analysis.
1. Assessment Stage
The first stage is to analyze the inventory to identify pain points, such as long lead times, high minimum order quantities, or location-related challenges, e.g. difficult transport routes or express airfreight costs. Companies have to ask themselves what the next best alternative would be when delivering the parts through traditional manufacturing, and what that alternative would actually cost — not just the procurement price per part, but the total cost including inventory, logistics, and downtime.
For a first quick assessment, the following matrix can help structure the thinking:
| Demand / Criticality | Why it matters | Role for 3D printing |
|---|---|---|
| Low demand, lower criticality | No minimum order quantities, no ramp-up costs | Primary use case — avoids overproduction and disposal of unused stock |
| Low demand, high criticality | Long lead times, high downtime costs | Often mandatory — traditional sourcing may be slow or unavailable |
| High demand, low criticality | Traditional manufacturing usually cheaper at scale | Supplementary/backup method for emergencies and global demand |
Parts with low demand and lower criticality
Additive manufacturing is particularly suited to low-volume parts, since there are no minimum order quantities and no ramp-up costs — a real competitive advantage. Companies should compare the number of parts required per year against the minimum order quantity for that part. If there’s a big gap between the two, 3D printing can be a good way to avoid overproduction, storage, and eventual disposal of thousands of unused parts.
The cost-efficient production of low volumes also makes 3D printing suitable for ramping up production until real demand is established, or for producing rarely or unexpectedly requested spare parts. Since 70-90% of spare part inventory typically consists of slow-moving parts, there’s real potential here to free up resources and cut costs.
As much as 70-90% of a typical spare part inventory consists of slow-moving parts — a significant share of resources that could potentially be freed up through on-demand production.
Siena Garden uses the Replique platform to digitally store “eternal” spare parts and have them produced on demand once a customer order comes in — extending product lifetime at close to zero extra cost. Alstom, for its part, had a small series of door stoppers — used to separate first and second class on a train — produced cost-efficiently and to industrial standard within just six weeks, using Replique’s decentralized manufacturing platform.
Parts with low demand and high criticality
When a part is critical to the product or process, 3D printing can become close to mandatory, since downtime can mean serious losses in revenue and customer satisfaction. Long lead times and high downtime costs for a specific part are the two factors to watch closely when analyzing inventory. This is especially true for parts with long service periods (e.g. more than 15 years), which traditional manufacturing may struggle to source at all. It applies, for instance, to parts for production machinery — in the automotive industry, one minute of downtime can cost up to $22,000–$50,000.
Parts with high demand and low criticality
Even for high-volume parts, where traditional manufacturing is generally the more cost-effective route, setting up additive manufacturing as a supplementary method can still be economically attractive — it gives the OEM the ability to react quickly in an emergency. Here, 3D printing works as a backup solution. For parts requested globally in particular, 3D printing can further reduce the risk of delivery delays, since a part can be produced at any local print farm close to the end consumer, without the need for lengthy customs procedures or expensive express shipments.
Not sure where your own inventory fits?
Get your parts screened for 3D printing feasibility.2. Technical Validation
The second step is technical validation, where parts are evaluated to make sure they’re actually 3D printable. This covers parameters such as size, materials, and overhangs, and becomes much easier when CAD files are available rather than just technical drawings. Software tools can help identify the right AM technology and material, flag potential issues before printing, and recommend design changes to optimize the part.
Redesigning a part for 3D printing can significantly improve its final cost, since additive manufacturing allows hollow and intricate structures that reduce the amount of material needed while keeping strength intact. That’s particularly useful where weight matters, such as in aerospace or automotive applications. Components that have traditionally been manufactured as multi-piece assemblies can also benefit, since 3D printing often allows them to be produced as a single part — one clear example is an air outlet that, printed additively, no longer needs the assembly step that traditional manufacturing would require.
3. Business Validation: TCO Analysis
With technical validation complete, the final step is business validation — using a total cost of ownership (TCO) analysis to weigh the economic feasibility of 3D printing against traditional manufacturing. On one side sit the cost of the printer and its maintenance, the cost of materials, and the cost of post-processing and finishing — or, if working with an external provider, simply the cost of the part through their service.
On the other side are the benefits: reduced lead times, reduced inventory costs, and reduced transportation costs. These are typically harder to quantify than a simple purchase price comparison, but these “hidden” costs play a major role in the true total cost of a part.
Various cases have shown that identifying up to 30% of an inventory as feasible for 3D printing is realistic.
Ready to run the numbers?
Let’s map out the TCO case for your parts together.Selecting the right parts for 3D printing is critical for a successful, high-quality outcome. The three steps outlined here — assessment, technical validation, and business validation including a TCO analysis — can guide companies through the selection process so they can capture the real benefits of additive manufacturing. If internal resources are missing to properly assess technical feasibility, a platform like Replique can be a significant lever for putting the technology to work.
FAQ
Getting started
What’s the first step in selecting parts for 3D printing?
Start by analyzing your existing inventory for pain points such as long lead times, high minimum order quantities, or complicated logistics. Compare the total cost of the current sourcing route — not just the unit price, but inventory, logistics, and downtime costs — against what 3D printing could offer instead.
Which parts are best suited to additive manufacturing?
Low-volume parts with no minimum order quantity requirements are the classic use case, since 3D printing avoids overproduction and disposal costs. Critical parts with long lead times or long service periods are another strong fit, since traditional manufacturing may struggle to source them at all. High-volume parts can also benefit as a backup or emergency production method, even if traditional manufacturing remains the primary route.
How do I know if a part is technically feasible to 3D print?
Technical validation checks parameters like part size, material requirements, and overhangs. It’s far easier with a CAD file than with technical drawings alone. Software tools can flag potential printing issues and suggest design adjustments, and in many cases a redesign can meaningfully improve the final part’s cost and performance.
Costs and validation
What does a TCO analysis for 3D printing include?
On the cost side: printer and maintenance costs, material costs, post-processing and finishing, or the price charged by an external print provider. On the benefit side: reduced lead times, reduced inventory holding costs, and reduced transportation costs. The benefit side is usually harder to quantify but often has the bigger impact on the total cost of a part.
What share of an inventory is typically feasible for 3D printing?
Case studies have shown that identifying up to 30% of a spare parts inventory as printable is a realistic outcome once both technical and business validation are applied.
What if we don’t have the internal expertise to evaluate feasibility?
This is exactly where a platform like Replique can help — offering part screening from both a technical and commercial perspective, and connecting companies to a network of manufacturing partners once suitable parts are identified.
