Certificates on a wall tell you a factory passed an audit once. These questions tell you whether it can build your product next month.
Start with what they have already built
Ask for a product they have run that resembles yours in board complexity, volume and test requirement — not their most impressive customer. A factory that assembles high-volume consumer boards is not automatically good at a 14-layer instrument board with press-fit connectors and conformal coating.
If the honest answer is that they have not built anything like it, that is not a reason to walk away. It is a reason to plan a pilot build and a longer first-article cycle.
Ask who buys the components
Turnkey sourcing is where most schedule risk lives. Ask which distributors they buy through, what happens when a part goes to a 40-week lead time, and who has authority to approve an alternate. If the answer is that they will "let you know", you are the one carrying the risk.
Franchised distribution and documented alternate approval are the two answers worth hearing.
Ask what happens on a bad batch
Every factory has yield excursions. What separates them is whether the excursion reaches you as a surprise or as a phone call. Ask for a real example: what failed, how it was caught, what the corrective action was, and how long it took.
A supplier who cannot recall a single yield problem is either new or not telling you much.
Ask about capacity, not capability
Capability is what the equipment can do. Capacity is whether there is a free line in the week you need it. Ask what percentage of their SMT hours are already committed for the next quarter, and what your job would displace.
Ask how they will hand the product back
One day you may move the product — to another factory, another region, or in-house. Ask what you would receive: the test fixtures, the programme files, the as-built BOM, the traveller history. A partner confident in the relationship will answer this without flinching.
Where we come in
Emsxchange runs this evaluation for you. Your enquiry is matched to audited suppliers with the right process and free capacity, you get one costed quote, and we carry the purchase order through to delivery. Send us your files and see what comes back.