Scales of production

There are four terms used to describe the scale of production in relation to manufacturing a product:

Prototypes and one-off production

There are many ways to produce a prototype - some are rough and look like models and others are well finished and function as intended. It is now possible to 3D print metal, and many engineering companies have welcomed this technology as 3D printing is classed as additive manufacture, rather than subtractive. Additive manufacture builds up the metal form in layers, whereas subtractive manufacture takes material away from a larger piece. There is very little waste when using additive techniques, making it more environmentally friendly.

Additive and subtractive manufacturing shown alongside each other. In additive, material is added to create a shape whereas in subtractive it is taken away from a larger piece, leaving waste.

A custom-made or bespoke product that is made from metal could be made based on a customer design specification. Products such as rings and jewellery are often made personally for a customer and only one will ever exist.

Batch production

Batch production is where many items of the same product are produced, such as a bike frame or parts for a metal fence. Many metal products are joined by welding, often done by hand rather than by machines, and the metal is held in place with a jig during the manufacturing process. The jig ensures that each part stays in place whilst the welding is completed.

Someone wearing protective clothing and a mask whilst welding a material, causing a spark.

When a product is made in a batch, it is often far cheaper per product than when making just one.

Example

A designer needs six 300 mm × 300 mm × 0.5 mm sheets of aluminium, which cost £5.00 each.

A 900 mm × 600 mm × 0.5 mm sheet costs £28.00. This information can be used to calculate which is better value for money.

Six 300 mm x 300 mm x 0.5mm aluminium sheets costing £5.00 each alongside one 600 mm x 900 mm x 0.5 mm aluminium sheet costing £28.00 for calculating material costs.

Cutting the larger sheet into six smaller sections would cost:

£28.00 ÷ 6 = £4.67 per sheet

Therefore, £5.00 - £4.67 = 0.33

= 33p saving per sheet

As a percentage:

(4.67 ÷ 5) × 100 = 93.4

100 - 93.4 = 6.6% saving per sheet

Question

For sheets of steel:

500 mm × 500 mm × 0.7 mm costs £6.00

1,000 mm × 1,000 mm × 0.7 mm costs £17.00

Four 500 mm x 500 mm x 0.7mm aluminium sheets costing £6.00 each alongside one 1,000 mm x 1,000 mm x 0.7 mm aluminium sheet costing £17.00 for calculating material costs.

How much of a saving, in both pounds (£) and percentage (%), could you make by getting the larger sheet cut into four pieces that are 500 mm × 500 mm?

£17.00 ÷ 4 = £4.25

£6.00 - £4.25 = £1.75 saving per sheet

As a percentage:

(4.25 ÷ 6.00) × 100 = 70

100% - 70% = 30% saving per sheet

Mass production

Mass-produced products are manufactured in large volumes, and often assembly line workers can be used to fit standard components, such as screws and hinges, to parts. Mass-produced metal products include door handles, barbecues and cooking utensils.

Continuous production

Continuous production takes place 24 hours a day, 7 days a week and, in some cases, 365 days a year. Many cars are made using a continuous production process, and the huge amount of sheet steel that is bought for this brings down the prices.

When cars are made using continuous production methods, most of the work in the factory is automated using robots, with sheet steel being cut and pressed, transported, welded and painted by them. However, people are needed to work alongside the robots to fit parts to the cars, as robots currently lack manual dexterity.

Multiple yellow robot arms working on building a car in a manufacturing plant.
An automated assembly line continually producing parts for the automotive industry