Quoting Iterative Prototyping Cycles

Most shops can quote a one-off prototype. The trouble starts when the customer says, “We’ll need three revisions before we lock the design.” Suddenly you’re guessing at rework, material changes, and schedule shifts — all while trying to keep the account profitable.

Iterative prototyping is standard in product development, but it breaks traditional quoting models. Fixed-price quotes either leave money on the table or scare off the customer. Time-and-materials creates uncertainty on both sides. The solution isn’t better guessing — it’s a quoting structure that matches how prototyping actually works.

Why Standard Quotes Fail on Iterative Work

A typical quote assumes a known geometry, fixed process, and single delivery. Iterative prototyping violates all three:

• Geometry evolves — wall thicknesses change, features add or disappear, tolerances tighten
• Processes shift — a part might start on FDM, move to SLA, then finish on CNC for functional testing
• Quantities fluctuate — one unit for fit check, five for user testing, twenty for pilot build

Quoting each revision as a separate job creates administrative overhead and gives the customer sticker shock every cycle. Rolling everything into one lump sum forces you to pad heavily for unknowns.

Structure Quotes in Phases, Not Revisions

Instead of quoting “Revision 1, Revision 2, Revision 3,” define phases by decision gates. Each phase ends when the customer makes a specific go/no-go decision:

1. Phase 1: Concept Validation — 1-2 units, fastest process, loose tolerances. Goal: prove the architecture works.
2. Phase 2: Functional Testing — 3-5 units, production-intent materials, tighter specs. Goal: verify performance requirements.
3. Phase 3: Pre-Production — 10-20 units, final process, full inspection. Goal: validate manufacturing readiness.

Each phase has a fixed price and clear deliverables. The customer approves one phase at a time. You only commit to the next phase after seeing the actual results of the previous one.

Define Revision Boundaries Explicitly

“Unlimited revisions” is a margin killer. Define what counts as a revision within each phase:

• Included: minor geometry tweaks (hole sizes, fillet radii), orientation changes, support strategy adjustments
• Excluded: material changes, process switches, feature additions, tolerance tightening beyond the phase spec

Put this in the quote. When the customer asks for a material swap in Phase 2, you reference the agreement and issue a change order — not a surprise invoice later.

Price for Learning, Not Just Parts

Iterative prototyping delivers information as much as parts. Your quote should reflect that:

• Include engineering review time for each phase — DFM feedback, process selection, risk assessment
• Build in a “learning buffer” (10-15% of phase cost) for the inevitable discoveries
• Offer a discount on Phase 3 if Phases 1-2 run consecutively with you — you’ve already done the setup and learning

This shifts the conversation from “cost per part” to “cost per design decision,” which is what the customer actually values.

Automate the Phase Transitions

Manual handoffs between phases create delays. A quoting system that supports phase-gated workflows lets you:

• Pre-configure each phase with its own process, material, and inspection rules
• Auto-generate the Phase 2 quote when Phase 1 ships, using actual data from the first build
• Track cumulative cost and lead time across the full program

Solvi’s quoting engine handles this by letting you template multi-phase programs and trigger subsequent phases automatically — so the estimator isn’t rebuilding quotes from scratch every two weeks.

Communicate the Schedule Honestly

Customers often underestimate how long iterations take. Your quote should show:

• Minimum time per phase (build + inspect + ship + review)
• Buffer for customer review cycles (assume 3-5 business days)
• Earliest start date for each phase based on current capacity

A Gantt-style view in the quote document helps stakeholders see the full timeline — and why compressing Phase 2 usually just shifts risk to Phase 3.

Conclusion

Iterative prototyping doesn’t have to mean iterative quoting chaos. By structuring around decision gates, bounding revisions, pricing for learning, and automating phase transitions, you protect margins and give customers the flexibility they need. Solvi helps digital manufacturers template and manage multi-phase prototyping programs from first quote to final delivery.