Waste (
muda) is defined by
Fujio Cho as "anything other than the minimum amount of equipment, materials, parts, space, and workers time, which are absolutely essential to add value to the product". Different types of waste have been defined in the form of a
mnemonic of "downtime": •
Defects: A defect is a product that is declared unfit for use, which requires the product to be either scrapped or reworked, costing the company time and money. Examples include a product that is scratched during the production process and incorrect assembly of a product due to unclear instructions. •
Over-production: Over-production refers to products made in excess or before it is needed. Examples include creating unnecessary reports and overproduction of a product before a customer has requested it. •
Waiting: Waiting involves delays in process steps and is split into two different categories: waiting for material and equipment and idle equipment. Examples include waiting for authorization from a superior, waiting for an email response, waiting for material delivery, and slow or faulty equipment. •
Non-Used Talent: Non-Used Talent refers to the waste of human potential and skill. The main cause is when management is segregated from employees; when this occurs, employees are not given the opportunity to provide feedback and recommendations to managers in order to improve the process flow and production suffers. Examples include poorly trained employees, lack of incentives for employees, and placing employees in jobs or positions that do not use all of their knowledge or skill. •
Transportation: Transportation is the unnecessary or excessive movement of materials, products, people, equipment, and tools. Transportation adds no value to the product and can lead to product damage and defects. Examples include moving products between different functional areas and sending overstocked inventory back to an outlet warehouse. •
Inventory: Inventory refers to an excess in products and materials that are unprocessed. It is a problem because the product may become obsolete before the customer requires it, storing the inventory costs the company time and money, and the possibility of damage and defects increases over time. Examples include excess finished goods, finished goods that cannot be sold, and broken machines on the manufacturing floor. •
Motion: Motion is unnecessary movement by people. Excessive motion wastes time and increases the chance of injury. Examples include walking to get tools, reaching for materials, and walking to different parts of the manufacturing floor to complete different tasks. •
Extra-processing: Extra-processing is doing more work than required or necessary to complete a task. Examples include double-entering data, unnecessary steps in production, unnecessary product customization, and using higher precision equipment than necessary. == See also ==