Assembly Services for Automotive Production
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Sub-assembly and kitting are off-line assembly work: components are built or grouped into a ready-to-install unit before they reach the production line. Kitting groups parts that already exist. Sub-assembly builds a component from several of them. Both remove work from the station without changing the line rate.
What Assembly Services Covers
OpTech Automotive runs assembly as a program we are accountable for, not a bench and a box of parts. The work is scoped to your bill of materials, your work instructions, and your line rate, then verified before anything leaves for the station.
The simplest way to tell these apart is what happens to the part. Assembly Services changes it: components are grouped, built, and verified against your bill of materials before anything reaches the line. Our managed labor, warehousing, and sequencing programs move it and time it. Each of those may kit along the way, because kitting is often a step toward their own outcome. Here it is the outcome.
That boundary runs the other way too. Just-In-Time Sequencing delivers kitted or loose parts in build order. Kitting is what goes into the container, sequencing is what order the containers arrive in.
Off-Line Assembly vs. Building It on the Line
Most plants start by building at the station, because that is where the part is needed. The distinction matters when the build content grows faster than the line rate allows.
Station Time You Get Back
Assembling at the station spends time the line rate has already allocated. Moving the build off the line returns that time without retiming the line or adding a station.
Caught Before It Reaches the Station
On the line, a wrong or missing component is found by the operator, mid-build, with the line moving. Off the line, it is found at verification, before the kit ships, with time to correct it.
Scale the Build, Not the Line
Adding build content on the line means adding people or stations to the line itself. Off the line, OpTech Automotive scales the build crew against your forecast without touching your line balance.
What an Assembly Services Program Includes
Scope is built around your bill of materials, your work instructions, and your line rate, not a generic assembly template.
Need coverage for something not listed here? Scope is defined during the capability assessment, not pulled from a standard service menu.
Assembly Services Solutions in the Field
From Capability Assessment to First Kit
Four steps. No lengthy vendor onboarding, and no handoff to a subcontractor you have never met. One coordinator owns the program from scoping through reporting.
Capability Assessment
We walk your bill of materials, the build content you want off the line, your line rate, and your delivery constraints, to scope what the assembly program actually needs to cover.
Program Design
Build location, work instructions, verification steps, change control, and the pricing model are built against your production calendar and your customer’s requirements, not a generic template.
Build Launch
The build runs live, with verification and escalation active from the first kit rather than phased in later.
Ongoing Reporting
Kit accuracy, on-time delivery, and escalation response are reported continuously, not at contract renewal.
Assembly Services FAQs
The questions manufacturing, quality, and supply chain teams ask before moving build content off their own line.
What is sub-assembly in automotive manufacturing?
Sub-assembly is the process of building a component from two or more parts before it reaches the main production line, so the operator installs one finished item instead of assembling it at the station. It is performed off the line, to the customer's bill of materials and work instructions, and verified before delivery.
What is the difference between kitting and sub-assembly, and when does a plant need each?
Kitting groups existing components into a ready-to-install set. Sub-assembly builds a component that did not exist before, by fastening, pressing, or joining parts together. A plant needs kitting when operators lose time searching and sorting. It needs sub-assembly when the build itself is taking station time the line rate cannot absorb.
What is the difference between Assembly Services and the kitting in your other programs?
Assembly Services changes the part. Our managed labor, warehousing, and sequencing programs move and time it. Those programs kit when kitting is a step toward their own outcome. Assembly Services is where building or grouping to your bill of materials is the deliverable, performed off the line before parts reach the station.
Who is accountable for a defect in a sub-assembly OpTech Automotive builds?
OpTech Automotive is accountable for the assembly work we perform and for defects traced back to our process, including the records that show what was built and verified. What that accountability covers financially is set in the program agreement rather than assumed, and it is scoped during the capability assessment before any commitment is made.
Does assembly work happen in our plant or at an OpTech Automotive facility?
Assembly work runs where it makes the most sense for your program: inside your plant, at an off-site warehouse, or a combination. Location changes the delivery method, the transit risk, and how a short kit is recovered, so it is decided during program design rather than assumed from a standard model.
Does your assembly work require its own PPAP submission?
It depends on what the work changes. Kitting a set of already-approved parts does not usually trigger a new submission. Building a sub-assembly can, because the assembly itself becomes a part with its own number. Which applies to your program is confirmed during program design, since the requirement comes from your customer.
How are bill-of-materials changes and engineering change notices handled mid-program?
Bill-of-materials revisions and engineering change notices are handled as part of the program, not as exceptions to it. A change routes to a named coordinator, work instructions and kit contents are updated before the next build, and the effective date is confirmed with you so old and new revisions do not run together.
What happens if a kit is short a component?
A short kit is caught at verification rather than at the station, which is the point of verifying before delivery. The shortage is flagged to a named coordinator, the kit is held or completed from available stock, and the root cause is traced to receiving, the bill of materials, or the build step.
How are torque, fastener, and test results documented?
Verification is a step in the build with a documented result, not a sample taken afterward. Which checks apply, whether torque values, fastener counts, or a functional test, comes from your work instructions. The records are captured as the work happens and retained, so they can be shown rather than reconstructed.
How is assembly work priced, per piece, per kit, or per hour?
Assembly work is priced per piece, per kit, or per hour, depending on the program. Per piece or per kit suits stable volumes and a fixed bill of materials. Per hour suits variable content, launches, and changeover work. Which model applies is set during the capability assessment, against your volume and build complexity.
Take the Build Off the Line
Share your bill of materials, the build content you want off the station, and your line rate and we will scope a capability assessment. We review what the operator is assembling today and what it costs you in station time, then come back with an assembly plan built on your schedule.