Efficient use of materials.

Designers reduce cost and waste by:

nesting parts using CAD/CAM to minimise off-cuts

designing around standard material sizes

using hollow sections and thin walls where appropriate

selecting efficient structural forms

Example: Efficient material use can be seen in laser-cut sheet metal, where components are nested to reduce waste, in I-beams and cellular beams used in construction, and in thinner glass bottles, which reduce raw material use while maintaining performance.

Accuracy, tolerances and waste reduction

Accuracy is essential for correct fit, ease of assembly, and effective sealing and function.

Automated machinery is used for very high volumes of identical components.

CNC machines are used where flexibility is required and multiple components with tight tolerances are needed.

Example: High accuracy is required in products such as engine components, flat-pack furniture fixing holes, and screw-top bottle threads, where poor tolerances would result in failure or poor performance.

Comparing bulk and one-off production

One-off production is: skilled, labour-intensive, and expensive.

Bulk production: enables automation, reduces unit cost, and benefits from bulk purchasing.

CAD/CAM enables mass customisation, combining efficiency with individual specification.

Example: This comparison can be seen between bespoke hardwood furniture and mass-produced flat-pack furniture, and in customised cars ordered online, which combine automated production with individual specification.

JiT strategies:

close supplier relationships

continuous improvement (Kaizen)

waste reduction (Muda)

Kanban stock control systems

Example: JiT manufacture was successfully adopted by Harley-Davidson, where motorcycles were produced only after customer orders were received.