is a
Japanese
Japanese may refer to:
* Something from or related to Japan, an island country in East Asia
* Japanese language, spoken mainly in Japan
* Japanese people, the ethnic group that identifies with Japan through ancestry or culture
** Japanese diaspor ...
word meaning "futility; uselessness; wastefulness", and is a key concept in
lean process thinking, like the
Toyota Production System
The Toyota Production System (TPS) is an integrated socio-technical system, developed by Toyota, that comprises its management philosophy and practices. The TPS is a management system that organizes manufacturing and logistics for the automobile ma ...
(TPS) as one of the three types of deviation from optimal allocation of resources (the others being ''
mura'' and ''
muri'').
Waste in this context refers to the wasting of time or resources rather than wasteful by-products and should not be confused with
Waste reduction
Waste minimisation is a set of processes and practices intended to reduce the amount of waste produced. By reducing or eliminating the generation of harmful and persistent wastes, waste minimisation supports efforts to promote a more sustainab ...
.
From an end-customer's point of view, value-added work is any activity that produces goods or provides a service for which a customer is willing to pay; ''muda'' is any constraint or impediment that causes waste to occur.
There are two types of muda:
* Muda Type I: non value-adding, but necessary for end-customers. These are usually harder to eliminate because while classified as non-value adding, they may still be necessary.
* Muda Type II: non value-adding and unnecessary for end-customers. These contribute to waste, incur hidden costs and should be eliminated.
Toyota's (Ohno's) Seven Forms of Waste
One of the key steps in lean process and TPS is to identify which activities add value and which do not, then to progressively work to improve or eliminate them.
Taiichi Ohno
was a Japanese industrial engineer and businessman. He is considered to be the father of the Toyota Production System, which inspired Lean Manufacturing in the U.S. He devised the seven wastes (or muda in Japanese) as part of this system. He ...
, "father" of the Toyota Production System, originally identified seven forms of ''muda'' or waste:
![Different kinds of waste in lean manufacturing](https://upload.wikimedia.org/wikipedia/commons/0/05/Different_kinds_of_waste_in_lean_manufacturing.png)
A mnemonic may be useful for remembering the categories of waste, such as TIM WOOD or TIM WOODS.
Transportation
Every time a product is touched or moved unnecessarily there is a risk that it could be damaged, lost, delayed, etc. as well as being a cost for no added value. Transportation does not add value to the product, i.e. is not a transformation for which the consumer is willing to pay.
Inventory
Whether in the form of raw materials,
work-in-progress (WIP), or finished goods, represents a capital outlay that cannot yet produce an income. The longer a product sits in one of these states, the more it contributes to waste. The smooth, continuous flow of work through each process ensures excess amounts of inventory are minimized.
Motion
In contrast to transportation, which refers to damage and transaction costs associated with moving the product, motion refers to the damage and costs inflicted on what creates the product. This can include
wear and tear
Wear and tear is damage that naturally and inevitably occurs as a result of normal wear or aging. It is used in a legal context for such areas as warranty contracts from manufacturers, which usually stipulate that damage from ''wear and tear'' w ...
for equipment,
repetitive strain injuries
A repetitive strain injury (RSI) is an injury to part of the musculoskeletal or nervous system caused by repetitive use, vibrations, compression or long periods in a fixed position. Other common names include repetitive stress disorders, cumula ...
for workers or unnecessary downtime.
Waiting
Whenever the product is not in transportation or being processed, it is waiting (typically in a queue). In traditional processes, a large part of an individual product's life is spent waiting to be worked on.
Overproduction
Making more of a product than is required results in several forms of waste, typically caused by production in large batches. The customer's needs often change over the time it takes to produce a larger batch. Over-production has been described as the worst kind of waste.
Over processing
Doing more to a product than is required by the end-customer results in it taking longer and costing more to produce. This also includes using components that are more precise, complex, expensive or higher quality than absolutely required.
Defects
Having to discard or rework a product due to earlier defective work or components results in additional cost and delays.
Unused skills
Organizations often under-utilize the skills their workers have or permit workers to operate in silos so that knowledge is not shared. This was added to the original seven forms of waste, as resolving this waste is a key enabler to resolving the others.
Alternative forms of waste
The eight forms of waste were developed for Toyota specific processes.
Other companies and individuals have elucidated or identified other forms of waste. Some examples follow:
Canon's nine wastes (, )
* ''Work-in-process waste'': e.g., stocking items not immediately needed
* ''Defect waste'': producing defective products
* ''Equipment waste'': idle or broken machinery; empty facilities; taking too long for setup
* ''Investment or expense waste'': overuse of resources for required output
* ''Indirect labor waste'': excess personnel due to unskillful use of indirect labor
* ''Human resources or talent waste'': employing people whose talents exceed job requirements, when the job can be mechanized or assigned to less skilled people
* ''Operations or motion waste'': Not working according to the best standards.
* ''Planning or product design waste'': Implementing processes or producing products with more functionality than necessary.
* ''Start-up waste'': The waste or inefficiency in the ramp-up or stabilization of the production of a new product.
Confusion
General uncertainty about the right thing to do, or absence of documented procedures and operating statements.
Self-doubt
Writer
Jim Womack described "thinking you can't" as the worst form of waste, quoting
Henry Ford
Henry Ford (July 30, 1863 – April 7, 1947) was an American industrialist, business magnate, founder of the Ford Motor Company, and chief developer of the assembly line technique of mass production. By creating the first automobile that mi ...
's
aphorism
An aphorism (from Greek ἀφορισμός: ''aphorismos'', denoting 'delimitation', 'distinction', and 'definition') is a concise, terse, laconic, or memorable expression of a general truth or principle. Aphorisms are often handed down by tra ...
:
Implementation
Shigeo Shingo
was a Japanese industrial engineer who was considered as the world’s leading expert on manufacturing practices and the Toyota Production System.
Life and work
After having worked as a technician specializing in fusions at the Taiwanese railw ...
divides process related activity into Process and Operation. He distinguishes "Process", the course of material that is transformed into product, from "Operation" which are the actions performed on the material by workers and machines. This distinction is not generally recognized because most people would view the "Operations" performed on the raw materials of a product by workers and machines as the "Process" by which those raw materials are transformed into the final product. Shingo breaks down the process into four phenomena, Transportation, Inspection, Processing and Delay.
He makes this distinction because value is only added during the processing steps in the process not by the transportation, inspection and delay steps. He states that whereas many see Process and Operations in parallel he sees them at right angles (orthogonal) (see
Value Stream Mapping
Value-stream mapping, also known as "material- and information-flow mapping", is a lean-management method for analyzing the current state and designing a future state for the series of events that take a product or service from the beginning of ...
). This starkly throws most of the operations into the waste category.
Many of the TPS/Lean techniques work in a similar way. By planning to reduce manpower, or reduce change-over times, or reduce campaign lengths, or reduce lot sizes the question of waste comes immediately into focus upon those elements that prevent the plan being implemented. Often it is in the operations' area rather than the process area that muda can be eliminated and remove the blockage to the plan. Tools of many types and methodologies can then be employed on these wastes to reduce or eliminate them.
The plan is therefore to build a fast, flexible process where the immediate impact is to reduce waste and therefore costs. By ratcheting the process towards this aim with focused muda reduction to achieve each step, the improvements are 'locked in' and become required for the process to function. Without this intent to build a fast, flexible process there is a significant danger that any improvements achieved will not be sustained because they are ''just'' desirable and can slip back towards old behaviours without the process stopping.
See also
*
Lean manufacturing
Lean manufacturing is a production method aimed primarily at reducing times within the production system as well as response times from suppliers and to customers. It is closely related to another concept called just-in-time manufacturing ( ...
*
Lean software development
Lean software development is a translation of lean manufacturing principles and practices to the software development domain. Adapted from the Toyota Production System, it is emerging with the support of a pro-lean subculture within the agil ...
*
Agile software development
In software development, agile (sometimes written Agile) practices include requirements discovery and solutions improvement through the collaborative effort of self-organizing and cross-functional teams with their customer(s)/ end user(s), ad ...
*
Total quality management
*
Theory of Constraints
References
External links
"The 7 Manufacturing Wastes""8 Wastes of Lean Manufacturing"
{{DEFAULTSORT:Muda (Japanese term)
Japanese business terms
Lean manufacturing