Muda (Japanese term)

Muda (無駄) is traditional general Japanese term for activity that is wasteful and doesn't add value or is unproductive, etymologically none (無)+ trivia or un-useful (駄) in practice or others. It is also a key concept in the Toyota Production System (TPS) and is one of the three types of waste (Muda, Mura, Muri) that it identifies. Waste reduction is an effective way to increase profitability. Toyota merely picked up these three words with prefix mu-, which every Japanese knows as product improvement program or campaign.

A process adds value by producing goods or providing a service that a customer will pay for. A process consumes resources and waste occurs when more resources are consumed than are necessary to produce the goods or provide the service that the customer actually wants. The attitudes and tools of the TPS heighten awareness and give whole new perspectives on identifying waste and therefore the unexploited opportunities.

Muda has been given much greater attention as waste than the other two which means that whilst many Lean practitioners have learned to see muda they fail to see in the same prominence the wastes of mura (unevenness) and muri (overburden). Thus whilst they are focused on getting their process under control they do not give enough time to process improvement by redesign.

The seven wastes

One of the key steps in Lean and TPS is the identification of which steps add value and which do not. By classifying all the process activities into these two categories it is then possible to start actions for improving the former and eliminating the latter. Some of these definitions may seem rather 'idealist' but this tough definition is seen as important to the effectiveness of this key step. Once value-adding work has been separated from waste then waste can be subdivided into 'needs to be done but non-value adding' waste and pure waste. The clear identification of 'non-value adding work', as distinct from waste or work, is critical to identifying the assumptions and beliefs behind the current work process and to challenging them in due course. Breakthroughs in SMED and other process changing techniques rely upon clear identification of where untapped opportunities may lie if the processing assumptions and beliefs are challenged.

The expression "Learning to see" comes from an ever developing ability to see waste where it was not perceived before. Many have sought to develop this ability by 'trips to Japan' to visit Toyota to see the difference between their operation and one that has been under continuous improvement for thirty years under the TPS. Shigeo Shingo, a co-developer of TPS, observed that it's only the last turn of a bolt that tightens it - the rest is just movement. This level of refined 'seeing' of waste has enabled him to cut car body die changeover time to less than 3% of its duration in the 1950s. Note that this period has allowed all the supporting services to adapt to this new capability and for the changover time to under multiple improvements. These multiple improvements were in new technologies, refining value required by 'downstream' processes and by internal process redesigns.

The following seven wastes identify and classify resources which are commonly wasted. They were identified by Toyota’s Chief Engineer, Taiichi Ohno as part of the Toyota Production System:

Defects

Quality defects prevent the customers from accepting the defected product. The effort to create these defects is wasted. New waste management processes must be added in an effort to reclaim some value for the otherwise scrap product.

Overproduction

Overproduction is the production or acquisition that hides production problems. Overproduction must be stored, managed and protected.

Conveyance

Each time a product is moved it stands the risk of being damaged, lost, delayed, etc. as well as being a cost for no added value. Transportation does not make any transformation to the product that the consumer is supposed to pay for.

Waiting

Refers to both the time spent by the workers waiting for resources to arrive, the queue for their products to empty as well as the capital sunk in goods and services that are not yet delivered to the customer. It is often the case that there are processes to manage this waiting.

Inventory

Inventory, be it in the form of raw materials, work-in-progress (WIP), or finished goods, represents a capital outlay that has not yet produced an income either by the producer or for the consumer. Any of these three items not being actively processed to add value is waste.

Motion

As compared to Conveyance, Motion refers to the producer or worker or equipment. This has significance to damage, wear, safety. It also includes the fixed assets, and expenses incurred in the production process.

Overprocessing

Using a more expensive or otherwise valuable resource than is needed for the task or adding features that are designed in but unneeded by the customer. There is a particular problem with this item as regarding people. People may need to perform tasks that they are over qualified for so as to maintain their competency. This training cost can be used to offset the waste associated with overprocessing.

Other candidate wastes

Other sources have proposed additional wastes. These may work for the proposers or they may overlap or be inconsistent with the originals which came from a coherent source.

Latent Skill

Organizations employ their staff for specific skills that they may have. These employees have other skills too, it is wasteful to not take advantage of these skills as well. "It is only by capitalizing on employees' creativity that organizations can eliminate the other seven wastes and continuously improve their performance."

Danger

Unsafe work areas creates lost work hours and expenses.

Poor Information

Age of electronic information and enterprise resource planning systems (ERP) requires current / correct master data details.

Material

In branches where the material cost is relatively high, loss of raw materials, intermediates and finished products can be a very important area of focus. This has been proven in the Printing Inks industry, and the same surely applies elsewhere.

Breakdown

Due to poor maintenance, equipment used to produce may breakdown. This can cause delays in production regularly. This is why we implement a TPM program (Total Productive Maintenance) Is a method used to achieve maximum equipment effectiveness through employee involvement.

Implementation

Shigeo Shingo makes an interesting observation about process related activity by dividing it 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 recognised. He makes this distinction because value is added to the product by the process but not by most of the operations. He states that whereas many see Process and Operations in parallel he sees them at right angles (orthogonal). This starkly throws most of 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 focussed 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 software development
• Agile software development
• Total Quality Management
• Mottainai (Regret muda or awake not to do muda in Japanese language)

External links

• "The 7 Manufacturing Wastes"