The Phase Nobody Budgets

A founder has a prototype that works. The natural next thought is to send the CAD to a factory and get a quote. What comes back is either a refusal, a price three times the estimate, or - worst - a cheap quote from a shop that will build exactly what the files say and ship a box of unusable parts.

Between a working prototype and a repeatable product sits a phase with no glamour and a real bill: production readiness, sometimes called manufacturing preparation or new product introduction. It typically runs 8 to 20 weeks and costs 15 to 35 percent of what the design phase cost. Teams that skip it do not save that money; they spend two to three times as much discovering the same problems through scrapped tooling and rejected lots.

What Preparation Actually Includes

Adapting the design to the chosen process. A prototype was built by whatever method was fastest, usually 3D printing and machining. Production uses molding, casting, stamping, or extrusion, and each imposes rules the prototype ignored: uniform wall thickness, draft on every vertical face, no undercuts that need a side action you cannot afford, ribs instead of thick sections, radii instead of sharp internal corners. This is the substance of design for manufacturing, and it commonly changes 30 to 60 percent of the part geometry without changing the product at all. Assembly gets the same treatment: fewer fasteners, self-locating features, one-direction assembly, and no operation requiring a third hand.

The manufacturing data package. A STEP file is not a release. A factory needs dimensioned drawings with datums and tolerances, material and finish specifications by grade, an assembly drawing with torque values and adhesive callouts, packaging and labeling artwork, and a revision-controlled index of all of it. What belongs in the package is spelled out in the manufacturing data package, and getting it right is the difference between a quote you can compare and one you cannot. Tolerances deserve particular attention: a drawing where every dimension carries a tight blanket tolerance can double the price for no functional reason, which is why what a manufacturing drawing must include is a costing question as much as an engineering one.

The bill of materials and alternates. Every part, with manufacturer part number, quantity per unit, unit cost at target volume, lead time, and at least one qualified alternate for anything with a lead time over eight weeks or a single source. Building it properly the first time, as described in the BOM guide, prevents the most common launch delay, which is a $0.40 connector with a 40-week lead time holding up an entire build.

Sourcing and quoting. Identifying candidate suppliers for each process, issuing an RFQ package that lets them all quote the same thing, evaluating responses on capability rather than price alone, and auditing the finalists. Expect three to six weeks and meaningful variation: quotes for the same part from qualified shops routinely spread two to one.

Tooling and fixtures. Specifying molds, dies, jigs, and assembly fixtures, then reviewing the toolmaker's design before steel is cut. Mold design review is the highest-leverage hour in the whole phase, since gate location, cooling layout, and ejection scheme are nearly impossible to change afterwards.

Test and quality procedures. Written incoming inspection criteria, an in-process check plan, end-of-line functional test, and the sampling rule that decides whether a lot is accepted. For anything electronic this means a production test fixture designed and built before the first lot, not after. It also means agreeing what the first parts must prove, through first article inspection against the drawing rather than against opinion.

The zero series. A small run on production tooling, with production operators, following the real work instructions. This is where cycle times, yield, and assembly problems become visible while they are still cheap; the mechanics are in the pilot production run.

What It Costs

For a modest consumer product with two or three molded parts, a PCB, and a handful of purchased components, engineering effort for production readiness typically runs $15,000 to $50,000, excluding the tooling itself. Complex products with multiple assemblies, certifications, or regulated markets run higher. Tooling is a separate line and usually the largest one.

Compare that to the cost of skipping it. A mold cut from an undrafted design is a $12,000 to $40,000 write-off. A BOM without alternates turns one obsolete component into a redesign and a lost season. A missing end-of-line test means the defect rate is discovered by customers, and the resulting return wave costs more than the entire preparation phase. Value engineering during this window also tends to pay for the phase outright, since the per-unit reductions found through value engineering multiply across every unit you will ever build.

Who Does It

Three arrangements are common, and each has a failure mode.

  • The design firm continues into preparation. Best continuity, since they know why every feature exists. Verify they have actual manufacturing engineers and factory experience, not only industrial designers and CAD.
  • The contract manufacturer does it. Often cheap or free, because the cost is recovered in unit price. The conflict is real: they will optimize for processes they own and the resulting package may not be portable to a second source.
  • An independent manufacturing engineering firm. Neutral, produces a portable package, and works for you in quoting. Costs more in fees and recovers it in supplier competition.

Whoever does it, insist the deliverable is yours: source CAD, drawings, BOM, test procedures, and supplier contact list, all under your control. A package you cannot take to another factory is not a package, it is a lock-in.

The Gate That Ends the Phase

Production readiness is finished when someone can answer yes to all of these without hedging. Every part has a drawing with tolerances and a named supplier. Every purchased component has a second source or a documented risk acceptance. Tooling is approved and sampled. Work instructions exist with photos. An inspection plan with sampling levels is agreed with the factory. A pilot run has been built and its defects have been closed out. Cost per unit at target volume is known within 10 percent. Anything unchecked on that list is a problem that will surface during your first real production order, when it is most expensive.

Get Your Product Production Ready

Projects House takes working prototypes through to a factory-ready release: DFM revisions, full data package, sourcing and RFQ management, tooling review, test procedures, and a pilot build. Send us your current design status and target volume through our contact form.