Types of wastes

While the elimination of waste may seem like a simple and clear subject it is noticeable that waste is often very conservatively identified. This then hugely reduces the potential of such an aim. The elimination of waste is the goal of Lean, and Toyota defined three broad types of waste: muda, muri and mura; it should be noted that for many Lean implementations this list shrinks to the last waste type only with corresponding benefits decrease.

To illustrate the state of this thinking Shigeo Shingo observed that only the last turn of a bolt tightens it—the rest is just movement. This ever finer clarification of waste is key to establishing distinctions between value-adding activity, waste and non-value-adding work.[17] Non-value adding work is waste that must be done under the present work conditions. One key is to measure, or estimate, the size of these wastes, in order to demonstrate the effect of the changes achieved and therefore the movement towards the goal.

The "flow" (or smoothness) based approach aims to achieve JIT, by removing the variation caused by work scheduling and thereby provide a driver, rationale or target and priorities for implementation, using a variety of techniques. The effort to achieve JIT exposes many quality problems that are hidden by buffer stocks; by forcing smooth flow of only value-adding steps, these problems become visible and must be dealt with explicitly.

Muri is all the unreasonable work that management imposes on workers and machines because of poor organization, such as carrying heavy weights, moving things around, dangerous tasks, even working significantly faster than usual. It is pushing a person or a machine beyond its natural limits. This may simply be asking a greater level of performance from a process than it can handle without taking shortcuts and informally modifying decision criteria. Unreasonable work is almost always a cause of multiple variations.

To link these three concepts is simple in TPS and thus Lean. Firstly, muri focuses on the preparation and planning of the process, or what work can be avoided proactively by design. Next, mura then focuses on how the work design is implemented and the elimination of fluctuation at the scheduling or operations level, such as quality and volume. Muda is then discovered after the process is in place and is dealt with reactively. It is seen through variation in output. It is the role of management to examine the muda, in the processes and eliminate the deeper causes by considering the connections to the muri and mura of the system. The muda and mura inconsistencies must be fed back to the muri, or planning, stage for the next project.

A typical example of the interplay of these wastes is the corporate behaviour of "making the numbers" as the end of a reporting period approaches. Demand is raised in order to 'make plan', increasing (mura), when the "numbers" are low which causes production to try to squeeze extra capacity from the process which causes routines and standards to be modified or stretched. This stretch and improvisation leads to muri-style waste which leads to downtime, mistakes and backflows and waiting, thus the muda of waiting, correction and movement.

The original seven muda are:

Transportation (moving products that is not actually required to perform the processing)
Inventory (all components, work-in-progress and finished product not being processed)
Motion (people or equipment moving or walking more than is required to perform the processing)
Waiting (waiting for the next production step)
Overproduction (production ahead of demand)
Over Processing (due to poor tool or product design creating activity)
Defects (the effort involved in inspecting for and fixing defects)
Later an eighth waste was defined by Womack et al. (2003); it was described as manufacturing goods or services that do not meet customer demand or specifications. Many others have added the "waste of unused human talent" to the original seven wastes. These wastes were not originally a part of the seven deadly wastes defined by Taiichi Ohno in TPS, but were found to be useful additions in practice. For a complete listing of the "old" and "new" wastes see Bicheno and Holweg (2009)

Some of these definitions may seem rather idealistic, but this tough definition is seen as important and they drove the success of TPS. The clear identification of non-value-adding work, as distinct from wasted work, is critical to identifying the assumptions 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 are challenged.

Lean implementation develops from TPS
The discipline required to implement Lean and the disciplines it seems to require are so often counter-cultural that they have made successful implementation of Lean a major challenge. Some would say that it was a major challenge in its manufacturing 'heartland' as well. Implementations under the Lean label are numerous and whether they are Lean and whether any success or failure can be laid at Lean's door is often debatable. Individual examples of success and failure exist in almost all spheres of business and activity and therefore cannot be taken as indications of whether Lean is particularly applicable to a specific sector of activity. It seems clear from the "successes" that no sector is immune from beneficial possibility.


Lean is about more than just cutting costs in the factory. One crucial insight is that most costs are assigned when a product is designed, (see Genichi Taguchi). Often an engineer will specify familiar, safe materials and processes rather than inexpensive, efficient ones. This reduces project risk, that is, the cost to the engineer, while increasing financial risks, and decreasing profits. Good organizations develop and review checklists to review product designs.

Companies must often look beyond the shop-floor to find opportunities for improving overall company cost and performance. At the system engineering level, requirements are reviewed with marketing and customer representatives to eliminate those requirements which are costly. Shared modules may be developed, such as multipurpose power supplies or shared mechanical components or fasteners. Requirements are assigned to the cheapest discipline. For example, adjustments may be moved into software, and measurements away from a mechanical solution to an electronic solution. Another approach is to choose connection or power-transport methods that are cheap or that used standardized components that become available in a competitive market.

An example program
In summary, an example of a lean implementation program could be:

With a tools-based approach
Senior management to agree and discuss their lean vision
Management brainstorm to identify project leader and set objectives
Communicate plan and vision to the workforce
Ask for volunteers to form the Lean Implementation team (5-7 works best, all from different departments)
Appoint members of the Lean Manufacturing Implementation Team
Train the Implementation Team in the various lean tools - make a point of trying to visit other non competing businesses which have implemented lean
Select a Pilot Project to implement – 5S is a good place to start
Run the pilot for 2–3 months - evaluate, review and learn from your mistakes
Roll out pilot to other factory areas
Evaluate results, encourage feedback
Stabilize the positive results by teaching supervisors how to train the new standards you've developed with TWI methodology (Training Within Industry)
Once you are satisfied that you have a habitual program, consider introducing the next lean tool. Select the one which will give you the biggest return for your business.
With a muri or flow based approach (as used in the TPS with suppliers).
Sort out as many of the visible quality problems as you can, as well as downtime and other instability problems, and get the internal scrap acknowledged and its management started.
Make the flow of parts through the system or process as continuous as possible using workcells and market locations where necessary and avoiding variations in the operators work cycle
Introduce standard work and stabilise the work pace through the system
Start pulling work through the system, look at the production scheduling and move towards daily orders with kanban cards
Even out the production flow by reducing batch sizes, increase delivery frequency internally and if possible externally, level internal demand
Improve exposed quality issues using the tools
Remove some people (or increase quotas) and go through this work again (the Oh No !! moment)


Lean leadership
The role of the leaders within the organization is the fundamental element of sustaining the progress of lean thinking. Experienced kaizen members at Toyota, for example, often bring up the concepts of Senpai, Kohai, and Sensei, because they strongly feel that transferring of Toyota culture down and across Toyota can only happen when more experienced Toyota Sensei continuously coach and guide the less experienced lean champions. Unfortunately, most lean practitioners in North America focus on the tools and methodologies of lean, versus the philosophy and culture of lean. Some exceptions include Shingijitsu Consulting out of Japan, which is made up of ex-Toyota managers, and Lean Sensei International based in North America, which coaches lean through Toyota-style cultural experience.

One of the dislocative effects of Lean is in the area of key performance indicators (KPI). The KPIs by which a plant/facility are judged will often be driving behaviour, because the KPIs themselves assume a particular approach to the work being done. This can be an issue where, for example a truly Lean, Fixed Repeating Schedule (FRS) and JIT approach is adopted, because these KPIs will no longer reflect performance, as the assumptions on which they are based become invalid. It is a key leadership challenge to manage the impact of this KPI chaos within the organization. A set of performance metrics which is considered to fit well in a Lean environment is Overall Equipment Effectiveness, or OEE.

Similarly, commonly used accounting systems developed to support mass production are no longer appropriate for companies pursuing Lean. Lean Accounting provides truly Lean approaches to business management and financial reporting.

After formulating the guiding principles of its lean manufacturing approach in the Toyota Production System (TPS) Toyota formalized in 2001 the basis of its lean management: the key managerial values and attitudes needed to sustain continuous improvement in the long run. These core management principles are articulated around the twin pillars of Continuous Improvement (relentless elimination of waste) and Respect for People (engagement in long term relationships based on continuous improvement and mutual trust).

This formalization stems from problem solving. As Toyota expanded beyond its home base for the past 20 years, it hit the same problems in getting TPS properly applied that other western companies have had in copying TPS. Like any other problem, it has been working on trying a series of countermeasures to solve this particular concern. These countermeasures have focused on culture: how people behave, which is the most difficult challenge of all. Without the proper behavioral principles and values, TPS can be totally misapplied and fail to deliver results. As one sensei said, one can create a Buddha image and forget to inject soul in it. As with TPS, the values had originally been passed down in a master-disciple manner, from boss to subordinate, without any written statement on the way. And just as with TPS, it was internally argued that formalizing the values would stifle them and lead to further misunderstanding. But as Toyota veterans eventually wrote down the basic principles of TPS, Toyota set to put the Toyota Way into writing to educate new joiners.

Continuous Improvement breaks down into three basic principles:

Challenge : Having a long term vision of the challenges one needs to face in order to realize one's ambition (what we need to learn rather than what we want to do‹and then having the spirit to face that challenge). To do so, we have to challenge ourselves every day to see if we are achieving our goals.
Kaizen : Good enough never is, no process can ever be thought perfect, so operations must be improved continuously, striving for innovation and evolution.
Genchi Genbutsu : Going to the source to see the facts for oneself and make the right decisions, create consensus, and make sure goals are attained at the best possible speed.
Respect For People is less known outside of Toyota, and essentially involves two defining principles:

Respect Taking every stakeholders' problems seriously, and making every effort to build mutual trust. Taking responsibility for other people reaching their objectives. Thought provoking, I find. As a manager, I must take responsibility for my subordinates reaching the target I set for them.
Teamwork : This is about developing individuals through team problem-solving. The idea is to develop and engage people through their contribution to team performance. Shop floor teams, the whole site as team, and team Toyota at the outset.