Documentation/Modules/Cost Estimation

Cost Estimation

Estimate manufacturing cost and process selection

Standards catalog

Validation: draft · Method band: formula

Open calculator

Indicative method: Indicative closed-form or numerical model

Assumptions

  • Linear elastic material behavior unless noted otherwise.
  • User is responsible for load combinations and load factors per the selected design code.
  • Design standard (US/EU/ISO) sets unit defaults and screening check labels — not a full code worksheet.

Limitations

  • Professional screening / indicative workspace — does not replace a licensed PE or official code compliance review.
  • Where specialized evaluators are not implemented, checks map solver outputs to catalog templates for orientation only.

Engineering checks

CheckINDUSEUISO
Relative cost indeximplemented———

Cost Estimation (cost-estimator) — draft

Purpose

Provide heuristic manufacturing cost estimates from material volume, process time, and overhead factors. Supports early design trade studies comparing material, machining, labor, and finishing costs.

Physics & theory

Part cost aggregates material, processing, and overhead. Material mass times cost per kg gives raw material cost; scrap fraction increases effective material usage. Machining cost scales with machine time and hourly rate; labor adds assembly or secondary operations. Finish and overhead apply as percentages on subtotals.

This is a parametric cost model, not activity-based costing or quoting from CAM toolpaths. Relative cost index supports comparing design alternatives rather than contractual pricing.

Manufacturing modules support design-for-manufacture decisions early in product development. Tolerance analysis should identify critical dimensions in the stack — tightening non-critical tolerances increases cost without improving function.

Fit selection balances assembly ease, alignment precision, and load transmission. Interference fits provide torque capacity without keys but require controlled press force and material compatibility.

Governing equations

Numerical method

Closed-form cost rollup (costEstimator/engine). Scrap capped at 90%; finish and overhead as configurable percentages of subtotals. Outputs cost per volume and cost per mass for normalization.

Inputs

ParameterDescription
materialVolume, materialDensityPart material
materialCostPerKgRaw material price
scrapPercentWaste fraction
machiningTime, machineRateCNC/machining
laborTime, laborRateAssembly/labor
finishPercent, overheadPercentMultipliers

Outputs

  • Material mass, scrap mass, cost breakdown, total cost, cost per volume/mass, effective material cost.

Design codes & checks

  • Indicative: Relative cost index (draft module)

Assumptions & limitations

  • Draft status: heuristic model for screening only.
  • No regional pricing, tooling amortization, or batch quantity discounts.
  • Machining time user-supplied — not linked to CAM Toolpaths automatically.
  • Excludes quality inspection, packaging, and logistics.

References

  1. Ostwald, P. F., & McLaren, T. S. Cost Analysis and Estimating for Engineering and Management. Pearson.
  2. ASM. Materials and Processing Costs in Design.
  3. Boothroyd, G., et al. Product Design for Manufacture and Assembly, 3rd ed.
  4. DIN 8580. Manufacturing processes classification (process selection context).
  5. PhyCalcPro verification benchmarks in src/data/verification/ where available for this module.
  6. Beer, F. P., et al. Mechanics of Materials, 8th ed. McGraw-Hill — foundational stress and deformation theory.
Maintainer note: Heuristic scoring model; low numerical coupling.