Quote Complete Assemblies Without the Guesswork

Most digital manufacturers can quote a single bracket, housing, or fixture in minutes. But when a customer sends an RFQ for a 12-part assembly with mixed processes — three CNC parts, four sheet metal brackets, five 3D printed jigs — the quoting workflow often falls apart. Estimators resort to spreadsheets, manual nesting guesses, and disconnected post-processing calculations. The result: quotes that take days, margins that evaporate, and production teams left guessing what was actually priced.

Why Assembly Quoting Breaks Down

The problem isn’t complexity — it’s fragmentation. A typical assembly quote forces estimators to jump between separate quoting methods for each process, manually aggregate material costs, guess at shared setup times, and hope post-processing steps don’t get missed. Common failure points include:

• Inconsistent BOM structures: Customers send STEP files, Excel BOMs, PDF markups, or napkin sketches — no standard input format.
• Process silos: CNC, sheet metal, and additive each have different cost drivers (toolpaths vs. bend allowances vs. support removal) that don’t map to a single quoting logic.
• Missing shared operations: Heat treatment, coating, hardware insertion, and final assembly labor apply across multiple parts but get priced per-part or omitted entirely.
• Nesting guesswork: Sheet metal and powder-bed fusion parts share build plates or nests, but estimators calculate utilization per-part instead of per-build.

These gaps compound. A 10% error on each of 12 parts becomes a quote that’s either uncompetitive or unprofitable.

Standardize the Input Before You Calculate

Start by defining a minimum viable BOM schema your shop accepts. Require customers to provide (or let your portal capture):

• Part-level process assignment (CNC, sheet metal, FDM, SLS, MJF, etc.)
• Material spec per part (grade, temper, filament/powder lot if traceability matters)
• Quantity per assembly and annual volume forecast
• Critical tolerances and inspection requirements
• Post-process requirements per part and at assembly level

Build this into your digital quote portal so customers structure the data for you. When the input is consistent, your engine can route each part to the correct quoting logic automatically — no manual sorting.

Route Each Part to Its Native Quoting Engine

An assembly quote shouldn’t force a single pricing formula. Instead, decompose the BOM and send each line item to the quoting model built for that process:

• CNC parts: Toolpath-based cycle time, tool wear, fixture amortization, 3/4/5-axis complexity multipliers.
• Sheet metal: Flat pattern nesting, bend sequence optimization, turret/laser piercing time, hardware insertion cycles.
• Powder bed fusion (SLS, MJF, DMLS): 3D nesting density, recoater time, powder refresh ratios, heat treatment schedules.
• FDM/FFF: Support volume, layer height tradeoffs, infill strategy, annealing requirements.

Each engine outputs a fully burdened part cost — material, machine time, labor, consumables, and process-specific overhead. The assembly quote aggregates these cleanly because every part was priced in its native logic.

Automate Multi-Part Nesting Across the Build

This is where most shops leave money on the table. When an assembly includes four sheet metal brackets and five SLS jigs, the brackets share a laser nest and the jigs share a build plate. Estimating utilization per part ignores the combinatorial optimization that drives real throughput.

Instead, group same-process parts and run nesting algorithms on the full set:

• Sheet metal: Nest all flat patterns together, calculate true sheet utilization, and amortize pierce time across the nest.
• PBF: Pack all SLS/MJF parts in a single build simulation, optimize Z-height, and calculate powder consumption for the full cake.
• FDM: Sequence prints to minimize changeover, batch by material/color, and account for purge towers.

The output is a per-build cost that you allocate back to each part by volume or bounding box — far more accurate than per-part estimates.

Capture Cross-Cutting Post-Process and Assembly Costs

Assembly quotes fail most often on the operations that span parts. Build these into your template as assembly-level line items, not per-part add-ons:

• Thermal processing: One heat-treat cycle for the whole assembly (or per-material batch) — cost by furnace load, not per part.
• Surface finishing: Powder coat, anodize, or tumble batches sized by rack capacity, not part count.
• Hardware installation: Press-fit inserts, rivets, standoffs — time per installation station, summed across the BOM.
• Final assembly labor: Standard work instructions with measured cycle times per sub-assembly step.
• Inspection: FAI on critical dims, CMM programming amortized across the run, gauge R&R if required.

Tag each assembly-level cost to the relevant parts so margins stay visible at both the part and assembly level.

Version Control the Whole Assembly Quote

Assembly RFQs rarely arrive final. Customers revise part counts, swap materials, add PEM nuts, or change coatings. Treat the assembly quote as a versioned object — not a spreadsheet you overwrite.

Track:

• BOM revision vs. quote revision (they diverge)
• Which parts changed and how (geometry, material, qty, process)
• Impact on shared nests, build plates, and post-process batches
• Customer approval status per revision

When the customer asks “what if we increase qty to 500?”, you re-run the affected nesting and post-process logic — not the entire quote from scratch.

Close the Loop With Production

The quote isn’t done when the customer says yes. Push the structured assembly quote — BOM, nesting maps, post-process routings, inspection plans — directly into your MES. That gives production:

• Pre-validated nest files for laser/PBF/FDM
• Work orders grouped by process cell
• Material kits staged per assembly
• Inspection plans linked to FAI requirements

No re-entry. No interpretation. The quote becomes the production plan.

Putting It Together

Quoting assemblies accurately isn’t about a bigger spreadsheet — it’s about a workflow that respects each process’s physics while optimizing across the whole build. The shops that win assembly work at healthy margins do three things differently:

1. They standardize the input so every part routes to the right quoting engine automatically.
2. They optimize nests and builds across the full assembly, not per part.
3. They price shared operations at the assembly level and version the whole thing as a single object.

Solvi helps digital manufacturers build this workflow with a quoting engine that handles multi-process BOMs, automated nesting across parts, and assembly-level post-process costing — all connected to an MES that turns the quote into a production plan. If assembly quotes are where your margin hides, it’s worth a look.