Scales of Production
Factories work at different scales of production. Mass production is where a factory produces millions of the same product all year round. Batch production creates thousands of a product and is able to change production to manufacture different things. One off production creates an item especially for a client.
Factories which mass produce products are set up to make the same thing repeatedly. They are highly automated and due to the high volume of the same product it can afford to invest in robots to speed up production.
Stages of production can be broken down into small repetitive tasks, often done by robots or unskilled employees. Because a product is being produced by the million with very little change it can repay the cost of expensive equipment fairly quickly. Products such as bottles, socks, toothbrushes, beans and anything that changes very little and is very popular will count as mass produced.
Some factories run all day and night which is called continuous production, this is particularly necessary in the production of frozen food, tin foil and chemicals where a pause in production may harm the product.
Production lines can work in several different ways - line production passes each step along a line of workers or robots one step at a time, cell production has one person making each product in full and progressive bundle systems (mainly textiles) where garments are sent down a line of workers to complete each task.
When a product is made in large numbers but only seasonally (e.g. swimwear) or change often (e.g. furniture) then they will be batch produced. Factories need more skilled workers to enable them to switch between tasks. Tools and machinery tend to be a little more manual and each stage of production would take place on a production line.
Batch production allows for changes in fashion where products can be adapted and changed easily.
One off Production:
One off products are manufactured as single items. These can be small (e.g. jewellery) or large (e.g. bridges) and anything in between. Specialist companies employ skilled staff to work with a client to design their brief. It is an expensive way to make things as it is labour intensive and takes a lot of time. In the fashion industry one off products are called couture. Furniture is called bespoke.
Other examples of one off manufacturing would be a prototype (to test a product before it goes into larger scale production), specialist engineering or handmade items.
Quality control, consistency and tolerance:
Quality control is vital for every product leaving a factory. If a product is faulty people won’t buy it and the company would lose money. Quality control checks at each stage of production stops faults happening along the production line. A series of faults would create too much waste or too many faulty products.
Checks would include:
The quality of the raw materials.
Lines are cut accurately to allow pieces to fit together well.
Images are printed clearly.
Periodic samples of products are tested as it would take too much time to test every product. This ensures consistency across the products for each stage of the production line.
Different manufacturing techniques would have different ways of ensuring quality:
Drilling depth is measured and controlled with a depth stop to stop it cutting too deep.
Laser cutters have their beams balanced and focused before cutting to ensure pin point accuracy.
Ink in printers is measured and checked throughout the process to keep colour bright.
Reference points on the surface of materials can help laser guide cutting tools to accurately cut.
Jigs are used to make sure repeated techniques (such as hole or countersink drilling) are all in the same place or depth. Templates, moulds and patterns also ensure that repetitive tasks are all exactly the same.
Exposure times in PCB’s need to be the same for each one or too much or too little copper will be removed.
Clothing is sampled to check shape, size, loose threads or components.
Tolerance is the amount of difference in measurement there can be at each stage of production. For example the distance between buttons on a shirt or where a hole is drilled.
To save materials and therefor money it can be cost effective to slightly change designs to make them fit onto stock sized materials, for instance being able to fit a dress pattern onto standard width fabric rather than having to join pieces or have a lot of waste cut off around it. Sheet wood or metal cutting could save money by having pieces cut which tessellate.