Quick answer
Use formulas to frame the decision, then validate with supplier and project reality.
These formulas are designed for early-stage engineering and commercial judgement. They are most useful when they make the next question clearer, not when they are treated as final truth.
Definition
Manufacturing break-even volume
The volume at which a higher-setup, lower-unit-cost process becomes cheaper overall than a lower-setup, higher-unit-cost process.
Example: GBP6,500 tooling / (GBP18 - GBP0.70) = roughly 376 units.
Definition
Assembly-time estimation
An early proxy for manual labour burden based on part count, joining effort, handling complexity, reorientation, and inspection steps.
Example: if one concept removes three joins and one reorientation step, it usually carries less recurring labour even before detailed process engineering exists.
Definition
Target COGS from retail price
The maximum factory cost a product can carry after tax, route-to-market costs, and the required business margin have been removed.
Example: if the retained price after VAT and route deductions is GBP95, hidden selling costs are GBP23, and the target margin is GBP19, the target COGS is GBP53.
Use the formulas with the matching tools
| Decision | Formula page answer | Tool for deeper comparison |
|---|---|---|
| When to tool up | Break-even volume | Manufacturing Payoff Visualiser |
| How labour-heavy is this concept | Assembly-time estimate | Assembly Time Estimator |
| What COGS can this route support | Target COGS from RRP | Target COGS by Route to Market |