The Manufacturing Readiness Checklist to Run Before Tooling

Most hardware products don't fail because the design was bad. They fail because the first production run cost three times the estimate, shipped six months late, and ate the budget needed to fix it. A real DFM review — run before you spend money on tooling — is the cheapest insurance a hardware team or small manufacturer can buy.

This is the checklist I run with engineering teams before they commit to a contract manufacturer. It mirrors the Manufacturing Readiness Scorecard but goes deeper on what a "yes" actually requires.

1. Build sequence is written down

A new technician should be able to assemble a unit correctly using only your written instructions. If the sequence lives in someone's head, it isn't repeatable, and your contract manufacturer will guess — usually wrong.

• Step-by-step assembly order with images for every step
• Torque specs and fastener callouts at the step they're used
• Inspection checkpoints between major sub-assemblies

2. Tolerances are verified mathematically

Eyeballing a stack-up is how you end up with a bin of parts that fit individually and none that fit together. Run a worst-case or statistical tolerance analysis on every critical interface before you release drawings.

3. Every critical component has a vetted supplier

"We'll source it later" is the most expensive sentence in hardware. For every part on the BOM:

• Named primary supplier with a real quote (not a website estimate)
• Identified backup or alternate part number
• Documented lead time at your expected order volume

4. Change control exists on paper

When the EE changes a resistor value, who updates the BOM, the drawing, and notifies the contract manufacturer? If the answer is "we email each other," you'll ship the wrong rev within six months.

5. First articles get inspected against the drawing

Every new supplier and every design change should trigger a formal first article inspection. A signed FAI report is your only defense when a part drifts out of spec three months into production.

6. Lot traceability is built in from day one

When a customer reports a failure, you need to trace that unit back to the supplier lot in under 10 minutes. Bolt-on traceability after a recall costs 10x what it costs to design in.

TL;DR

If you can't check off all six of these before tooling, the cost-and-schedule risk is real. Run the scorecard to see where your gaps are, then close them in order of cost-to-fix.