Muda and Waste in Lean

Question

What are the muda in lean?

Answer

Muda is a Japanese term for wastefulness. It was adopted as part of the Toyota Production System to refer to seven broad types of inefficiencies in manufacturing operations. It is a prominent feature of lean thinking. The seven Muda are:

Transport

This is the movement of goods where value is not added. It uses time and introduces risk of damage.

Inventory

Goods that are stored use time, space and introduce risk of spoilage or damage, but are not contributing value. Inventory is not just finished goods, but can be work in progress, components and even equipment.

Motion

This refers to the movement of goods and equipment (including people) during processing. Motion introduces complexity to the process which can increase errors, and uses time.

Waiting

This is the delay whilst goods or other resources are moving between production processes. It introduces delay, which means slower lead times and higher costs.

Overproduction

Where production exceeds demand, creating inventory.

Over Processing

Is when a product receives more work to reach a finished state than is necessary, sometimes due to adding features that are not valued by the customer.

Defects

These are faulty goods or processes, that introduce costs and delays.

References