Manufacturers, of anything from cakes to computer chips, have numerous ways of organizing production. One of these methods is called batch production. This is when, instead of manufacturing things singly, or by continuous production (think of the I Love Lucy episode in the chocolate factory for an example of the latter), items are manufactured in batches. A specific process for each item takes place at the same time on a batch of items, and that batch does not move onto the next stage of production or inspection until the whole batch is done.

For example, in small bakeries and in numerous homes, as opposed to large food manufacturing companies, cookies are baked in batches. You first must make your dough, then place the dough onto baking sheets, and then bake them. You are limited into how many cookies you can produce at one time by the number of baking sheets and ovens you possess, and by the size of bowls you have available to mix each batch.

This is batch production, since you do bake a large number of cookies at the same time, and you can’t skip from one process to the next until each process is complete. You can’t start cooking the cookies until you’ve made the dough, and you can’t remove the cookies from the oven (in most cases) until all the cookies are done, unless you’ve got an oven with a conveyor belt. There are necessary steps that apply to the whole batch of cookies. Also cooking may require you to bake in individual batches, increasing the final time between finishing the dough, and actually having completed baking all the cookies.

Sometimes batch production is necessary when a manufacturer is producing similar things, but with variants. For instance, if you manufacture two colors of the same shoe, you probably use batch production. Any dyeing of leather or fabric can’t apply to the whole set of shoes you want to manufacture, since they’re different colors. This can mean stopping in between each batch to change or clean machines, or prepare to add new dyes for the next variation. The necessity of stopping between batches is called "down time," and is why some people call batch production an inefficient manufacturing process. Time needed to prepare equipment or machines for the next batch can reduce total amount that can be manufactured, and take longer in total production time.

Another example of batch production is found in thin film coating of materials, like lenses, computer screens and the like. A coating machine can hold a finite number of the item being produced, and it can take several hours to over a day to apply the coatings needed in order to produce one batch. After materials are coated, they move on to the inspection process, while the coating machine must be readied for the next batch. This resetting of the machine may take considerable time, and may require numerous steps before the next batch can be placed in the machine.