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

Konstantin Dolgan

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.

Engineer marking draft angle and wall thickness notes in red on a plastic part drawing next to a molded enclosure
A real review produces marked-up geometry and a decision list, not a green checkmark from an automated quote engine.

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

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 Lanpdt 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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