Batch size of one

Set up time is the amount of time needed to adjust tools and to retool for various product. Long set ups a change over time make the production of batches with a small no. of units too expensive.

However, the creation of large batches leads to substantial lead time delays and the creation of high inventory levels. The JIT philosophy is to decrease and ultimately eliminate set-up times. E.g. by investing in advanced manufacturing technology some machines setting can be adjusted automatically instead of manually.

Alternatively some set up times can be eliminated entirely by reducing products, so that markets do not have to be reset each time a different product has to be made.

If the set up times are approaching zero, then there’s no advantage production in batches and therefore the optimal batch size can be one. With a batch size of one, the work can flow smoothly to the next stage without the need for and to schedule the next machine to accept this item.