Most multi-process manufacturing builds don’t fail because of the hardest features. Problems usually show up in the coordination between one step and the next, outside any single process.
Take a part that needs machining, casting, welding, and finishing. Each step is complex on its own, and most shops handle their piece well. The machinist and the plating house both meet their specs. The trouble comes from managing multiple manufacturing vendors at once, since each one is focused on its own job, its own timeline, and its own piece of the drawing.
A real example
Not long ago, we had a build where plating was scheduled a day before final inspection confirmed a key feature was correct. On paper, everyone did their job. The plater met their deadline. The plating and inspection schedules just weren’t connected.
This happens a lot. An assembly gets built using an old fit because the assembler never heard about a change from two revisions ago. A finishing vendor only sees the part they’re working on, not the full drawing, so a finish meant for one surface gets applied everywhere. Those are coordination problems, and they happen when no one is watching the handoffs between vendors.
We’ve seen the same thing on a build that combined an additive prototype with a production tool. The additive vendor hit their spec. The tooling shop hit theirs. Nobody had flagged that the transition itself needed its own check, since the printed part was never meant to carry the same tolerance as the molded version that followed it. Two vendors who never talked to each other left a gap neither one owned. Our post on prototype to production covers that transition in more detail.
The intent on the print has to survive the whole trip
A drawing starts out clear, with a tolerance callout, a finish spec, and an inspection requirement already built in. The question is whether the intent behind the print survives four separate handoffs before the part ships: engineer review, vendor selection, production, and inspection. Each one is a place where it can quietly shift.
It’s rarely anyone’s fault outright. An engineer reviewing the print might read a note slightly differently than the person selecting the vendor. The vendor selected might interpret a tolerance differently than the shop running it. By the time a part reaches inspection, the standard it’s checked against isn’t always the one the customer specified. Someone has to own that scope from the first review to the last inspection, or it drifts a little at every stop. That drift is where most quality escapes start.
How we handle it
Managing multiple manufacturing vendors on one build takes more than a spreadsheet of due dates. Our engineers review the entire build package before we send a quote, beyond the individual line items. If there’s a transition from additive to molding, a machined feature that has to survive plating, or a tolerance stack across several vendors, we want to spot it in the drawings. It’s much cheaper to find these issues now than during final inspection.
We keep a vetted vendor network for CNC machining + sheet metal fabrication + injection molding + additive + finishing + assembly. Each process is matched to a shop with proven experience on that step, and capability and tolerance claims come from that network, tracked shop by shop. You get one number, one timeline, and one contact. We inspect all parts in San Clemente before shipping, so the final check is always ours, under PE’s ISO 9001:2015, AS9100D Compliant, and ITAR Registered quality system.
The alternative, splitting the work yourself, has its own math. We break it down in the hidden cost of splitting a BOM across multiple portals.
What we need from you
Send the whole package. Prints or models for every step, finish and inspection requirements for each one, and some sense of how it all comes together at the end. Let us know if something’s already sourced or underway. The more we can see up front, the faster we can tell you where the real risk sits, before it turns into a missed date.
Frequently asked questions
One point of contact reviews the entire drawing package before quoting, then owns every handoff between vendors until the part ships.
Rarely a single hard feature. Delays usually come from vendors working off different revisions, different schedules, or incomplete visibility into the rest of the build.
Yes, through a vetted vendor network where each process is matched to a shop proven on that step, coordinated by one team.
