Choosing a Production Method for 300 Versus 30,000
A designer has developed a flat-pack desk organiser made from 3 mm birch plywood. It has six interlocking parts, two of which require a curved cut and a small engraved logo. The client initially wants 300 units for a museum shop, printed with the museum's name. A year later, the same client wants 30,000 units for a national retail chain, with the same shape but a different logo and a lower unit price. The designer proposes laser cutting for both runs. The manufacturer quotes: laser cutting is accurate to 0.1 mm with no tooling cost, but the per-unit cut time is 11 minutes. For the large run, a die-cutting and press-forming route is quoted with a $9,000 tooling cost and a per-unit time of 40 seconds.
1. Evaluate the designer's proposal to laser cut both runs, using the quoted figures.
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Laser cutting is appropriate for 300 units and inappropriate for 30,000, and the numbers show why.
- Small run: No tooling cost means the entire budget goes into units. At 11 minutes per unit, 300 units is about 55 machine-hours - manageable, and the 0.1 mm accuracy suits the interlocking joints and the engraved logo without extra processes. Laser cutting also allows the logo to change between the museum and retail versions with no setup penalty. This is the correct choice.
- Large run: 30,000 units at 11 minutes is about 5,500 machine-hours. Even ignoring cost, that is a production scheduling problem. Die cutting at 40 seconds per unit is roughly 333 machine-hours - a sixteen-fold reduction in machine time - for a one-off $9,000 tooling cost spread across 30,000 units, or $0.30 per unit.
- The trade-off: tooling is a fixed cost that only pays back at volume; laser is a variable cost that punishes volume. The crossover is where the tooling cost equals the machine-time saving, which at these figures occurs in the low thousands of units. Below it, laser wins; above it, die cutting wins.
- Quality risk: die cutting and press forming must still hold tolerance on the interlocking joints. The designer should require a sample from the tool before committing, because a cheaper process that produces loose joints creates returns.
The proposal is therefore half right: correct for 300, wrong for 30,000.
2. The retail chain wants the logo engraved as before. Explain how this requirement interacts with the process choice and what the designer should recommend.
Read the worked answer
Engraving is a per-unit, per-variation operation, and it behaves differently under each process.
- Under laser cutting, engraving is free in tooling terms: the logo is a line in the cut file. Changing it costs a file edit. This is a strong argument for laser at low volume and for short-run or personalised variants at any volume.
- Under die cutting and press forming, the logo must be formed by the tool. That means the logo is cut into the die, so a logo change requires die modification or a new die - a real cost and lead time. The retail chain's logo must therefore be finalised and frozen before the tool is made. If the chain is likely to run seasonal or co-branded variants, the die route becomes inflexible.
- Alternative: separate the logo from the forming operation - form the part with the die, then apply the logo by a secondary process such as pad printing or a laser engraving pass on the formed part. This keeps the die generic and the branding changeable, at the cost of an extra operation per unit.
Recommendation: die cut and press form the body for the 30,000 run, and apply the logo as a separate operation, with the tool designed so the logo area is flat and accessible. Confirm the logo artwork is locked before tooling. This preserves the cost advantage of volume production without making the design hostage to a single logo.