The best method of production depends on the type of product being made and the size of the market. Small firms operating in the service sector, such as plumbers, use job production because each customer has individual needs. Niche manufacturers of items such as made-to-measure suits would also use job production because each item they make is different.
Batch production is used to meet group orders. For example, a set of machines could be set up to make 500 size 12 dresses and then adjusted to make 600 size 12 dresses. Two batches have been made.
Flow production is used to mass produce everyday standardised (all the same) items such as soap powder and canned drinks. Economies of scale lead to lower unit costs and prices. Not many small manufacturers can afford the investment needed to mass produce goods. They instead opt for either batch or job production.
There is usually a trade off between unit costs and meeting specific customer needs. Flow production offers economies of scale and low costs for a one-size-fits-all product.