What a design for manufacturing review actually checks
A DFM review is a line-by-line audit of a design against the process that will make it. Here is the checklist, what it costs and what it typically saves.
August 29, 20261 min read
Written by Konstantin Dolgan, Ph.D., NPDP
Founder & CEO, Product Development Engineer
Published August 29, 2026
A design for manufacturing review is an engineer auditing your CAD against the specific process that will produce it, feature by feature, before any tooling is bought. It typically takes three to ten working days and costs $1,500 to $5,000. On a molded program it routinely prevents a tool change that would have cost more than the review itself.
What does a DFM review check?
Process | What gets checked |
|---|---|
Injection molding | Draft angle, wall thickness uniformity, parting line, gate and ejector locations, undercuts, sink risk, shrink and material choice |
CNC machining | Tool access, internal corner radii, depth-to-diameter ratios, workholding, number of setups, tolerance stack |
Sheet metal | Bend radii, relief cuts, minimum flange length, hole-to-bend distance, hardware clearance |
PCB assembly | Component availability, panelization, test points, keepouts, stencil and reflow constraints |
Assembly | Fastener count, access for tools, orientation errors a line worker could make, assembly time per unit |
How is it different from an automated DFM check?
Automated checks in a quoting portal look for geometry the machine cannot make. They are useful and free. They do not ask whether the part should exist in that form at all, whether two parts should be one, whether the tolerance you called out is achievable in that material, or whether the assembly sequence works with human hands. Those questions are where the money is.
What does a DFM review cost and what does it save?
Scope | Cost | What it commonly prevents |
|---|---|---|
Single molded part | $1,500 - $2,500 | One tool modification: $1,500 - $6,000 |
Enclosure assembly, 4 - 8 parts | $3,000 - $5,000 | A re-cut plus 4 weeks of schedule |
Full product, enclosure plus PCB | $5,000 - $9,000 | A respin plus a failed certification attempt |
Frequently asked questions
Who should run it?
Ideally someone who is not the person who drew the part and does not profit from the tooling order. A tool shop will review your design honestly but through the lens of the tool they want to sell. An independent engineering review answers to the product, and can tell you to change the design instead of buying the tool.
Where LA NPDT fits?
We run reviews as a fixed-fee engagement with a marked-up model, a written issue list and a call to walk through it. It works on its own, or as the first step of a larger program. See our DFM guide , our prototyping capabilities , or what low volume molding really costs . Proof from our own work: DFM on the QMS2GO voice recorder settled wall thickness, draft, and assembly order before tooling was cut.
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