Muda

Muda is the Japanese word for waste: any activity or step that uses up time or resources without creating value for the customer. The term comes from the Toyota Production System (TPS), the production method Toyota built around quality. The word targets the process rather than the people doing the work. It names the activities the process can do without.

Every process contains steps that add nothing for the customer or for the organization's goals. A team that tracks muda spots these steps, questions them and removes them instead of accepting them as unavoidable.

TPS traditionally sorts muda into seven categories:

• overproduction, making more than the customer needs
• over-processing, adding features or steps nobody needs
• waiting, when people or equipment stand idle
• transportation, moving products or materials for no reason
• inventory, storing more products or materials than needed
• motion, unnecessary movements of people or equipment
• defects, errors that have to be corrected

Removing muda raises efficiency, cuts costs and improves quality. Teams do it with Lean Manufacturing or Lean Six Sigma, tracking down the sources of waste one process at a time. Poka-yoke targets defects by making a mistake impossible to make in the first place. Removing muda is continuous improvement work, since each waste removed brings the next one into view.