QMS in Manufacturing: How We Control Quality Across a Vendor Network

As our customers go deeper into their supply chains, one question comes up more often on sales calls: how do you manage your QMS when you don’t run every machine yourself? It’s the right question. A quality management system that only covers your own building doesn’t protect a part that’s machined in one shop, heat treated in a second, and anodized in a third.

Here’s what a manufacturing QMS is supposed to do, what the standards require when work is outsourced, and how we apply it across our network.

What a QMS is, in plain terms

A quality management system is the documented set of processes a company uses to make sure what it delivers meets requirements, every time. ISO 9001:2015 is the baseline standard most manufacturers follow. AS9100D builds on ISO 9001 with added requirements for aviation, space, and defense, including product safety, configuration management, counterfeit part prevention, and tighter control of suppliers.

A certificate or compliance statement says the system exists. Whether it protects your part depends on how it handles the work that happens outside the four walls.

What the standards require for outsourced work

ISO 9001:2015 clause 8.4 covers “externally provided processes, products and services.” In short, it says outsourcing a process doesn’t outsource responsibility for it. The clause requires a company to:

• Evaluate, select, monitor, and re-evaluate suppliers against defined criteria, and keep records of those decisions and any actions they trigger.
• Set the type and extent of control based on how much a supplier’s work affects the customer’s requirements, and verify the output through inspection, audits, or approvals.
• Communicate requirements clearly to each supplier, including specifications, approval and release of product, required qualifications, and how performance will be monitored.

AS9100D adds a longer list of what must be flowed down to suppliers, including required tests and inspections, product acceptance techniques, design and development controls, and the quality system requirements the supplier must meet. Flow-down is also one of the main defenses against counterfeit parts. We covered the aerospace side in What AS9100 Compliant Actually Requires of a Vendor.

Where outsourced quality usually breaks

Most escapes don’t come from a shop that can’t machine. They come from gaps in the handoffs:

• A drawing revision that reaches the machine shop but not the plater
• A special process like heat treat or passivation done by a sub-tier vendor nobody approved
• Inspection done before finishing, so plating buildup on a bore is never measured
• Material certs that don’t travel with the parts
• A nonconformance fixed on the floor without a root cause, so it comes back on the next lot

We wrote more about this pattern in Where Quality Escapes Actually Start.

How PE’s QMS works across our network

PE is AS9100D Compliant and operates under ISO 9001:2015. Our QMS is built around the fact that we coordinate work across a network of shops, so supplier control is the center of it, not an appendix.

Supplier qualification. Every shop completes our supplier qualification survey and is reviewed for equipment, materials, tolerance capability, certifications, and capacity before it receives a drawing from us. Shops that handle controlled work must meet ITAR and data security requirements.

Approved vendor list. Qualified shops go on an approved list, scoped to the processes and materials they’ve proven. A shop approved for aluminum milling isn’t automatically approved for titanium or for welding.

Requirements flow-down. Each purchase order carries the drawing revision, material and certification requirements, special process requirements, inspection requirements, and any customer-specific clauses.

First article inspection. New parts and revised parts get a first article inspection, documented to AS9102 when the program requires it.

Inspection before shipment. Parts come back to San Clemente for inspection before they ship to you. We measure after finishing, so coating buildup on critical features is checked against the drawing.

Nonconformance and corrective action. When a part misses spec, we contain it, determine root cause with the shop, and track corrective action to closure. Repeat issues affect where future work goes.

Ongoing monitoring. Every order adds to each shop’s record for quality and on-time delivery, and that history decides where the next drawing goes. Because we see each shop’s performance across many jobs, we catch trends a single buyer would only find after a bad lot.

Our full credentials, AS9100D Compliant, ISO 9001:2015, ITAR Registered, and NIST 800-171 Compliant, are on our compliance page. Shops interested in joining the network can start on our vendor page.

Questions to ask any supplier about their QMS

1. Which standard does your QMS follow, and when was it last audited?
2. How do you qualify and approve the shops and outside processors you use?
3. What do you flow down on purchase orders to sub-tier suppliers?
4. Where are parts inspected, and is inspection done after finishing?
5. How do you handle nonconformances and track corrective action?
6. Can you show traceability from raw material certs to finished parts?

For aerospace and defense buyers, the answers to questions 2 and 3 matter most, because that’s where outsourced quality is won or lost.