**1. Introduction**

In the view of many senior industrial engineers and managers, the production philosophy that emerged in Toyota during the 1950s represented a major paradigm shift in the way of thinking about production. The previous milestone had been the mass production paradigm exemplified by the creation of the production and assembly lines. The assembly line concept developed at Ford (curiously another car construction company) revolutionized the industry and society of that time (beginning of the twentieth century). This paradigm produced huge cost reductions and it made possible for people from all over the world to gradually gain access to products that they were unable to have before. There is a less positive side of this way of working, especially in the way operators were seen by the system. The human operator was seen in this system as a purely mechanical resource with the ability to repeat small operations over long periods of time. This repeatability was seen, and is seen still, as a way to achieve high efficiency gains because it is admitted that those who do repeatedly the same operation become masters at doing that operation. With experience, we began to understand the problems that can result from this approach, namely an increase in errors that lead to loss of quality, greater risk of accidents, greater risk of developing musculoskeletal injuries and greater propensity for demotivation at work.

Although Toyota had been using its new production paradigm in its factories since the early 1950s, the first scientific publications on TPS emerged much later. It was not until the 1980s that both Taiichi Ohno and Shigeo Shingo – the two engineers to whom the development of TPS is essentially attributed – published in English about this new paradigm, their concepts and main techniques and practices. Although Shingo's work (translated by Andrew Dillon), entitled "A Revolution in Manufacturing: The SMED System" (Shingo, 1985), was published earlier, it does not present TPS in general, but rather a concrete methodology, called SMED (Single Minute Exchange of Die), specially designed to reduce equipment setup times. Thus, the first English-language book on TPS was that of Taiichi Ohno, entitled "Toyota Production System: Beyond Large-Scale Production" (Ohno, 1988).

However, it was in 1977 that the first scientific paper on TPS was published in English [1]. This article featured several facets of TPS, including technical aspects such as kanban number calculation (way of controlling production, explained below). However, what aroused the most interest in this publication was one of the two fundamental concepts of TPS. The authors state that TPS is based on two fundamental concepts, the first being the "reduction of the cost of eliminating waste" and the second "treating workers as human beings and with consideration". Although the former is "relatively" easy to understand, the same cannot be said of the second. In fact, none of the concepts are easy to grasp and practice in its fullness, but the second is much more complex. This side of the TPS is also referred by Mike Rother in his book about Toyota Kata [2] as the invisible side of the Toyota approach. This side is also referred by the Shingo model as the social science part of the TPS. It is exactly on this invisible side or social sciences side that the West has struggled to understand and master.

This chapter is dedicated to continuous improvement (CI), and CI is only really effective if the less visible side of the TPS more related to people and culture is seriously taken into account. The continuous improvement (CI) concept is not fully understood by every manager, practitioner, or academic. The three main misconceptions are: (1) CI frequently assumed as being the same as Lean; (2) any improvement is CI, and (3) occasional improvements are CI.

CI is one of the five principles of Lean Thinking and not the same as Lean Thinking. CI is a very important component of Lean but there are other important components as well. Lean without CI is not Lean at all but Lean is more than just CI. There is another word, "Kaizen", which is also used frequently and adds to the confusion. The meaning of *Kaizen* is something similar to continuous improvement but that same word is also used as including the other dimensions that are observed in Toyota factories such as pull production concept, value and waste, visual management, and so on. For many industrial engineers and managers *Kaizen* is similar to *Lean* or TPS itself. CI is only one part of Lean or part of the TPS while the other part is in short a set of principles that define the direction that the CI should follow, as depicted in **Figure 1**.

In contrast, it is wrong to consider any improvement as CI. Any improvement that is not aligned with the defined direction or "true north" cannot be considered as an improvement. Improvements must be increments toward the direction that is defined by the top management people (see **Figure 1**). Let us imagine that the direction is defined as being toward one-piece-flow. The meaning is that the effort should always be in finding solutions to reduce the lot size again and again. Then by some reason a team of engineers promotes an "improvement" that results in a reduction of production cost per unit achieved with bigger lot size and a consequent increase in inventory. Can that "improvement" be considered an improvement? The answer is no because the direction defined was exactly the opposite, the equivalent of pursuing lot size reduction.

Finally, an occasional improvement is not CI. Many articles are published where authors referenced CI which only described a single occasional improvement, either being a setup reduction project or layout improvement project resulting in less transport and motion waste. In reality, these type or actions are important for companies' competitive, no doubt about it, but CI is completely different. CI is

**33**

*Continuous Improvement*

**2. Reference models**

*Continuous improvement direction.*

**Figure 1.**

**2.1 Lean thinking**

*DOI: http://dx.doi.org/10.5772/intechopen.93638*

the platform, the systems, the structure, and routines that allow the generation of

The production management and organization models that are used here as frameworks to CI are all of them inspired from Toyota approach to production or the Toyota model itself. These models will be here described basically in terms of their principles because their principles lead the possible practical solutions devel-

During the 1970s and 1980s, Western companies gradually became aware of what Toyota was doing, especially car manufacturers, because of the impressive results they were achieving. Terms such as *Just In Time* and *Kanban* became very popular as referring the Toyota practices during the 1980s but the word "Lean" as referring the general Toyota approach to production was introduced in 1988 [3] and later popularized by the famous book "The Machine that Changed the World" [4]. The word "lean" attached to words such as "production", and "manufacturing", started to be part of the vocabulary of industrial engineers and managers around the world. Lean as a way of thinking, called "Lean Thinking", was then proposed by

• Identify value: The idea is that one should try to identify as best as possible what the market interprets as value for the products that the company offers in the market. It is much more important to interpret the value given by the customer to the different characteristics of our product than the value given by the creator of the product itself. This idea is very much linked to popular knowledge "No One Should Be a Judge in his Own Cause". The value should not be given by the cost of the product. Many of the costs that are associated with the product may be associ-

ated with characteristics that are not recognized as value by the customer.

• Identifying the value chain: Once identified what is the value of a product from the customer's point of view it is important to identify which processes add value and which processes do not add value and try to eliminate or reduce the latter.

improvements in a continuous, stable and sustainable way.

oped and implemented in organizations that adopt them.

[5] and supported by the following five principles:

*Concepts, Applications and Emerging Opportunities in Industrial Engineering*

struggled to understand and master.

as depicted in **Figure 1**.

of pursuing lot size reduction.

ment is CI, and (3) occasional improvements are CI.

Although Shingo's work (translated by Andrew Dillon), entitled "A Revolution in Manufacturing: The SMED System" (Shingo, 1985), was published earlier, it does not present TPS in general, but rather a concrete methodology, called SMED (Single Minute Exchange of Die), specially designed to reduce equipment setup times. Thus, the first English-language book on TPS was that of Taiichi Ohno, entitled "Toyota Production System: Beyond Large-Scale Production" (Ohno, 1988).

However, it was in 1977 that the first scientific paper on TPS was published in English [1]. This article featured several facets of TPS, including technical aspects such as kanban number calculation (way of controlling production, explained below). However, what aroused the most interest in this publication was one of the two fundamental concepts of TPS. The authors state that TPS is based on two fundamental concepts, the first being the "reduction of the cost of eliminating waste" and the second "treating workers as human beings and with consideration". Although the former is "relatively" easy to understand, the same cannot be said of the second. In fact, none of the concepts are easy to grasp and practice in its fullness, but the second is much more complex. This side of the TPS is also referred by Mike Rother in his book about Toyota Kata [2] as the invisible side of the Toyota approach. This side is also referred by the Shingo model as the social science part of the TPS. It is exactly on this invisible side or social sciences side that the West has

This chapter is dedicated to continuous improvement (CI), and CI is only really

effective if the less visible side of the TPS more related to people and culture is seriously taken into account. The continuous improvement (CI) concept is not fully understood by every manager, practitioner, or academic. The three main misconceptions are: (1) CI frequently assumed as being the same as Lean; (2) any improve-

CI is one of the five principles of Lean Thinking and not the same as Lean Thinking. CI is a very important component of Lean but there are other important components as well. Lean without CI is not Lean at all but Lean is more than just CI. There is another word, "Kaizen", which is also used frequently and adds to the confusion. The meaning of *Kaizen* is something similar to continuous improvement but that same word is also used as including the other dimensions that are observed in Toyota factories such as pull production concept, value and waste, visual management, and so on. For many industrial engineers and managers *Kaizen* is similar to *Lean* or TPS itself. CI is only one part of Lean or part of the TPS while the other part is in short a set of principles that define the direction that the CI should follow,

In contrast, it is wrong to consider any improvement as CI. Any improvement that is not aligned with the defined direction or "true north" cannot be considered as an improvement. Improvements must be increments toward the direction that is defined by the top management people (see **Figure 1**). Let us imagine that the direction is defined as being toward one-piece-flow. The meaning is that the effort should always be in finding solutions to reduce the lot size again and again. Then by some reason a team of engineers promotes an "improvement" that results in a reduction of production cost per unit achieved with bigger lot size and a consequent increase in inventory. Can that "improvement" be considered an improvement? The answer is no because the direction defined was exactly the opposite, the equivalent

Finally, an occasional improvement is not CI. Many articles are published where

authors referenced CI which only described a single occasional improvement, either being a setup reduction project or layout improvement project resulting in less transport and motion waste. In reality, these type or actions are important for companies' competitive, no doubt about it, but CI is completely different. CI is

**32**

**Figure 1.** *Continuous improvement direction.*

the platform, the systems, the structure, and routines that allow the generation of improvements in a continuous, stable and sustainable way.
