Batch size

Concept

The number of units made or moved together before the next step starts. Large batches cut changeovers but raise stock and lead time; small batches do the opposite.

Description

Batch size, in German Losgröße, is how many units are made or moved together before the next step can start. Each batch waits while the others in it are processed, so a larger batch means longer waiting for every unit and more work in progress.

Plants choose large batches mainly because changeovers are costly. The classic economic order quantity formula balances changeover cost against holding cost, but lean thinking asks a different question: how can changeover time be cut so that smaller batches become affordable? Smaller batches shorten lead time, show quality problems sooner and make the plant more flexible. The extreme is one-piece flow, where each unit moves on as soon as it is done.

Related topics in brief

• iFAKT GmbH · Related to · Organization
  Stuttgart-based consulting company and software specialist for Industry 4.0, founded in 2001, that helps manufacturers plan and optimize production and logistics processes; developer of the Polaris software.
• Setup time · Related to · Concept
  The time a machine or line is stopped to switch from one product or batch to the next, from the last good part of one to the first good part of the next.
• SMED · Related to · Concept
  A method for shortening changeover and setup times on machines by separating the work that needs the machine to be stopped from the work that can be done while it runs, and then simplifying both.
• Work in progress (WIP) · Related to · Concept
  Work in progress is material or product that has started its production route but is not yet finished; too much WIP ties up material and space and hides problems in the flow.
• Lead time · Related to · Concept
  The total time from the start of an order or part until it is finished, including all waiting. In most plants, waiting makes up far more of it than actual work.
• Heijunka · Related to · Concept
  A lean method that levels production by volume and mix over time, so a plant follows a steady, repeating pattern instead of swings in orders, which reduces stock, overtime and lead time.

Glossary

Experts and companies for this topic

• Mirko Peters · Microsoft MVP

Maintained by Mirko Peters (Microsoft MVP) · Last updated: 2026-11-11