Quoting Multi-Material Assemblies Without Chaos

Most quoting systems handle single-process, single-material parts just fine. But the moment a customer sends an RFQ for an assembly — say, a CNC-machined aluminum housing with overmolded silicone seals, press-fit bronze bushings, and laser-etched anodized brackets — the spreadsheet cracks.

Each material has its own pricing model. Each process has its own setup, run time, and yield assumptions. And every handoff between processes adds labor, inspection, and risk. If you treat the assembly as a sum of independent parts, you miss the integration costs. If you lump it into one big quote, you lose visibility into where margin lives or dies.

Why Assemblies Break Standard Quoting

The root cause is dimensionality. A single-part quote has three variables: material, machine time, and post-processing. An assembly multiplies those by every component, then adds:

• Procurement lead times for purchased hardware (inserts, fasteners, bearings)
• Receiving and inspection steps for incoming components
• Kitting and staging labor before each process
• Inter-process inspection (first-article on the housing before overmolding, for example)
• Assembly labor, tooling, and fixtures
• Final inspection and packaging requirements

Miss one of these, and the job either bleeds margin or gets quoted so high you lose the bid.

Structure the Quote Around the Build Sequence

Don’t quote by BOM line item. Quote by operation sequence. Map the actual flow through your shop:

1. Raw material procurement (bar stock, filament, sheet, purchased parts)
2. Primary manufacturing operations (CNC, print, laser, form)
3. Intermediate processing (heat treat, anodize, tumble)
4. Sub-assembly steps (press-fit, bond, weld)
5. Final assembly and test
6. Pack and ship

Each step gets its own cost bucket: setup, run, labor, consumables, scrap allowance, and queue time. This mirrors how your MES will schedule the work — so the quote and the shop floor speak the same language.

Handle Purchased Components With a Separate Ledger

Hardware, inserts, bearings, and electronics shouldn’t live in the same cost model as your manufactured parts. Create a purchased-part ledger that tracks:

• Supplier, lead time, and MOQ
• Landed cost (unit + freight + duty + receiving inspection)
• Buffer stock policy (do you order 10% extra for attrition?)
• Obsolescence risk for long-lead items

When the assembly quote runs, it pulls the current landed cost from this ledger — not a static cell in a spreadsheet. If a bearing lead time jumps from 2 to 8 weeks, the quote reflects it automatically.

Model Handoffs Explicitly

Every handoff between processes or work centers is a cost event. Capture it as a discrete line:

• Move time (forklift, cart, conveyor)
• Staging space allocation
• Inspection criteria and sampling plan
• Rework loop probability (historical data: what % of overmolded parts get rejected at final?)

Even a 15-minute staging step matters when you’re running 500 assemblies. That’s 125 hours of indirect labor — often invisible in part-level quotes.

Use a Parent-Child Quote Structure

In Solvi, you can build the assembly as a parent quote with child quotes for each manufactured component. The parent rolls up material, labor, and overhead from children, then adds assembly-specific operations (kitting, final assembly, test, pack). Benefits:

• Each child quote uses the right process formula (CNC vs. FDM vs. sheet metal)
• Changes to a component (material swap, tolerance tweak) recalc only that child
• You can version child quotes independently — critical when engineering iterates on one part
• Production sees discrete work orders per operation, not one monolithic job

This structure also lets you substitute a child quote with a Job Board partner’s price if you’re outsourcing a process — keeping the parent assembly quote intact.

Validate With a Pre-Production Checklist

Before the quote goes out, run a quick sanity check:

• Are all purchased parts quoted at current landed cost with correct lead times?
• Does every manufactured component have a DFM review flag?
• Are inter-process inspection points defined and priced?
• Is assembly labor based on a time study, not a guess?
• Does the total quote margin meet your floor after the full roll-up?

If any answer is “no,” the quote isn’t ready — even if the customer needs it yesterday.

Conclusion

Multi-material assemblies are where quoting either becomes a competitive advantage or a margin trap. The shops that win this work consistently don’t guess — they structure quotes around the actual build sequence, isolate purchased-part volatility, and model every handoff. Solvi lets you build parent-child quote structures that map directly to your shop’s workflow, so complex assemblies get accurate, profitable quotes without the spreadsheet chaos.