Qualify the second supplier before you need one.

Problem

The only assembler who had ever built the product stopped answering. There was no second source, no transferable test fixture, and no documentation that was not in that assembler's head.

Context

A router for community networks, built in batches of 500. Single-sourced from the start because the first assembler had been generous with a small team.

What they did

1. 1.Rebuilt the test fixture from the schematic rather than asking for the original back.
2. 2.Wrote the assembly instructions from a filmed build rather than from memory.
3. 3.Paid a second assembler for a 50-unit pilot before committing a production batch.
4. 4.Kept the pilot going at 50 units a quarter after the switch, so a third source was never a cold start.

What to avoid

• •The test fixture turned out to encode three undocumented calibration constants, found only when the new assembler's yields came back wrong.
• •The first assembler's quoted price had been below cost for two years, which nobody discovered until they got a market quote.
• •Qualification was scoped as a purchasing task and took an engineer full-time for six weeks.

Sources

• Assembler transition post-mortemMesh & Mortar engineering notes

Related lessons

• Order the long-lead part before the design is finished.→
• Read the returns before you read the reviews.→