What Is The Lean Manufacturing System?
Lean Manufacturing system is a production system developed by Toyota in Japan in 1950.
It is based on waste reduction – originally divided into seven categories, now into eight.
Waste is all activities that do not add any value to the customer.
Lean Manufacturing is more than a methodology. Today its principles influence the way of thinking and acting within some companies.
It is practically a philosophy , as the lean mentality it proposes must be absorbed by the company’s organizational culture.
How And Where Did Lean Manufacturing Originate?
Toyota’s production system emerged in the years following World War II .
These were difficult years for Japan , which was on the losing side and saw its economy devastated.
This need motivated us to create a system that involved little inventory, short cash flow and production efficiency, without sacrificing quality.
Industrial engineers Taiichi Ohno and Eiji Toyoda began developing it in 1948 .
Originally, it was not known as Lean Manufacturing (we’ll talk about the origin and meaning of this term later), but as the Toyota Production System, or TSP.
Pre-Lean Movements – Fordism/Mass Production
The first major revolution in the automobile industry took place in the United States, starting in 1914, when Henry Ford created the first assembly line with automation of some processes.
With moving walks, the vehicles under construction moved, not the workers.
In this way, it was possible to produce several automobiles at the same time, with each worker or group of workers responsible for a step in the process.
It may seem simple today, but at the time it was a great innovation that allowed the mass production and popularization of cars.
Decline Of Fordism And Rise Of Lean
After World War II, Japan’s economy was devastated and was not able to buy technology from the West.
In addition, the Japanese market was small and demanded a large variety of products, which required production in small batches, as opposed to mass production that preached Fordism.
Japanese engineers visited Ford plants in the United States to learn about their model, which Ohno and Toyoda perceived as outdated after decades since the Fordist revolution.
One of the problems was rigidity: parts were produced on a high scale, but for a single model of car, which resulted in stopped inventories and a lot of waste .
It was then that these engineers perfected this model and created the Toyota Production System, now known as Lean Manufacturing.
The lessons of Fordism were very important for the development of Lean Manufacturing, which became the new model to be followed in the automobile industry.
What Does The Word Lean Mean?
Lean is a word in the English language, whose translation commonly used in the context of companies is “ lean ”.
Lean is an adjective that characterizes something that has been dried. In the figurative sense, a lean company is one that has reduced expenses and waste.
Manufacturing is already manufacturing, but in English the term is used to refer to industrial production.
Lean Manufacturing, therefore, can be translated as lean manufacturing or, to be clearer but less succinct, lean industrial production system .
As we explained earlier, it was not Toyota engineers who named this system Lean Manufacturing.
The term was coined by authors James Womack, Daniel Jones and Daniel Ross, who published, in 1990, the book The Machine That Changed the World .
The work was the result of a five-year study by the Massachusetts Institute of Technology (MIT) on the history and future of the automobile.
Years later, Womack and Jones published the book The Lean Mindset in Business: Eliminate Waste and Create Wealth , which resulted in the definitive popularization of Toyota’s production concepts.
What Are The Main Objectives Of The Lean Manufacturing Process?
Among the main objectives of Lean Manufacturing, we can mention:
Cost Reduction
Before allowing for greater profit, one should think of reducing production costs as an opportunity to differentiate .
Before, the price of a product or service was defined by the sum of the cost of the product and the profit desired by the company. Currently, who sets the price of a product or service is no longer the company but the customer.
He sets the price he wants to pay after reviewing the same product against competitors.
In this new scenario, the only variable that is within the reach of the company is the cost, which the lower it is, the greater the company’s profit.
Continuous Improvement
Lean Manufacturing does not reduce waste in the same model as an external consultancy , which evaluates the scenario, makes a diagnosis, proposes changes in the company and ends its work.
Lean is a philosophy that must be incorporated into the company’s organizational culture , which implies creating processes to continually identify opportunities to “dry up” waste.
It aims to continually achieve better and better results. Then, after a process has been improved, this new process is re-evaluated again after some time in search of further improvements. This cycle is endless.
Production Agility
By improving production agility, a manufacturer is able to serve a larger market without having to expand its structure.
Greater Productive Capacity
This objective is directly related to the previous one. The more agile a factory, the greater its production capacity.
It is very important to note, however, that this objective is not an end in itself. In lean, you increase production when you know there is demand to absorb it .
Otherwise, you would not be reducing waste, but increasing it.
Work Environment Improvements
Lean Manufacturing should not be confused with obsolete practices that increase productivity at the expense of employees’ quality of life.
In addition to the obvious ethical and human issue , ensuring a good work environment combats waste, as it reduces turnover and workers’ absence due to illness and accidents.
5 Basic Principles Of Lean Manufacturing
In the following topics, learn about the five principles of the Lean Manufacturing system.
Value
Knowing how to identify what is value in your product is essential to recognize waste.
Any process has three types of activities:
- those that add value, that is, the customer is willing to pay a higher price for a product or service to have this activity and, therefore, must be maximized
- those that do not add value, however, are necessary. We can cite as an example the administrative activities of companies, such as the generation of payroll
- those that do not add value and are not necessary. These are waste and must be disposed of.
It is important to mention that the answer to the question “Does it add value or not?” may be different for each person. That’s why it’s important to be clear about who your target audience is.
The secret here is to focus on the customer : he will define what this value is.
Value Stream
From the definition we just talked about, it is possible to identify which steps add value and which do not.
The value stream is the set of activities, sequenced or not, that add value or not, carried out by a company so that a product or service goes from conception to launch. From the order to the customer‘s hand.
It consists of:
- Material Flow: In a Lean process, the product is moved from one stage that creates value to another that creates value
- Flow of information: in a Lean process everyone knows the customers’ needs, problems are solved and there is a management over them
- People Flow: In a Lean process, the employee’s work is reproducible and can go from one value-creating step to another
Continuous Flow
Continuous flow is the ability to produce without interruption to meet customer needs quickly.
This includes processing orders quickly to ensure low inventory.
Pull Production
While push production is defined from a demand forecast, in pull production, products are manufactured only when there is demand , eliminating the need for inventory as they go straight to the point of sale .
Perfection
As we highlighted before, the waste reduction proposed by lean should never compromise the quality of what is produced.
None of the principles and techniques of this production system can affect the value offered to the customer.
8 Sources Of Waste Fought By Lean
You’ve already learned that the great purpose of Lean Manufacturing is to reduce a company’s waste, right?
But what are these wastes? To repeat: these are processes that do not directly result in added value.
It is not possible to completely eliminate waste because, as we will now see, much is considered waste in lean.
The objective is to dry, to reduce as much as possible their impact on production.
Waste is divided into the following categories:
1. Transport
Movement of tools, inventory, equipment and products beyond what is necessary. It is wasteful because it does not add value to the customer.
He doesn’t care about the transport activity, he doesn’t pay extra for it. Transport losses also impact energy waste (electrical or other types), for example.
Another example is the sending of exaggerated emails, unnecessary trips to the printer or transporting goods or raw materials from one area to another in order to change the layout of the warehouse.
2. Inventory
Excessive inventory means having resources at a standstill – which can even spoil. An example is the inventories of inputs, raw materials or even final products.
Inventories serve as a safety margin to hide process inefficiencies.
This leads to increased costs due to handling and storage, as well as space problems, disorganization of warehouses, and long delays in the search for goods.
3. Movement
It’s different from transportation because it’s about people. Examples are: the movements of an employee who needs to walk between sectors daily to pick up tools or documents.
It can also be considered wasteful for an employee to attend excessive meetings, look for inputs in an unorganized warehouse or move in a zig-zag pattern during a production process due to equipment and tools not being arranged in a sequential and logical manner.
4. Wait
It is created when a material, information, people or equipment is not ready to be used.
Some examples: idle employees, documents awaiting signature or products stopped due to lack of dispatch are examples of this type of waste.
5. Overproduction
It is to produce something before and/or in greater quantity than the customer needs. It occurs, for example, when an extra quantity of parts is produced, in order to supply the defective ones.
Other examples are creating reports that no one reads and printing unnecessary information.
6. Excessive Processing
Refers to any operation or process beyond what the customer needs. Sometimes companies end up improving so much products or services in order to exceed customer expectations that they end up contemplating more features than those required.
This reflects in waste, since the customer is not willing to pay more for this differential.
Some examples are: too many and unnecessary meetings, polishing a car for longer than necessary, duplicate entry of similar data in different departments.
7. Rework
Occurs when there is a repetition or correction of a process. Occurs when products or services have a characteristic that is out of specification or customer expectations, and therefore does not meet the requirements for use.
It’s the easiest waste to visualize. Other examples are: repeating part of the execution of a project due to poor initial planning, waiter changing the soda with ice when the order was without ice, calling the plumber at home to fix the repair you made and it didn’t work
8. Intellectual
This waste is manifested when employees have knowledge and skills that are not properly used by the company.
Some examples are: discussion of the solution of a problem involving only specialists and ignoring the opinion of associates who experience the routine, a work group that does not suggest improvements in the day to day.
The 5S Philosophy
The 5S methodology is widely used in the Lean Manufacturing system, as it aims to lead and mobilize a company towards total quality .
For this, it follows five concepts whose Japanese words that represent them begin with the letter S.
Are they:
- Seiri (utilization): is the idea of keeping only what is strictly necessary for the service to be done in the workplace
- Seiton (organization): establishes that the place where each company resource is kept must be defined, identified and signaled
- Seiso (cleanliness): with the sense of cleanliness, it is easier to identify signs of resource degradation, reducing the risk of breakdowns
- Seiketsu (health and hygiene): identifies possible damages to the health of employees, seeking to correct ergonomic problems, for example
- Shitsuke (self-discipline): employees must comply with what has been established and at the same time have the autonomy to manifest proactive behavior.
JIT (Just In Time)
It aims to manufacture with no or minimal in-process inventory, resulting in a very short lead time with huge cost savings. It benefits quality and also promotes employee motivation.
The main idea of just-in-time production is linked to production on demand, that is, first the product is sold and only after that is the raw material purchased and the product manufactured.
The raw material stock only contains enough for a few hours of production, which can be a bit daring for planning .
Standardization Of Activities
Another objective of Lean Manufacturing is the standardization of work. The aim is to establish clear, specific and understood methods, aligned among all the performers.
By reducing variability, training of new employees is facilitated , risks are reduced, and a common basis for improvement activities is created.
For standardization to be possible, documentation is essential.
Documents commonly used for the standardization of production in the lean system are the process capability chart, combination table and standardized work diagram.
Quick Tool Exchange SMED (Single Minute Exchange Of Die)
The SMED method aims to reduce the time of the equipment setup process to be used in a given production.
In other words, it is a set of practices that reduces the preparation time of machines and tools to perform the service.
Thus, the non-productive periods of the factory are minimized as much as possible, reducing costs and increasing production capacity.
SMED implementation involves steps such as scope definition, process flow mapping , time measurement and results control.
Poka Yoke
Poka Yoke is a Japanese term that means something like “ mistake-proof ”.
It is a system that aims to prevent failures and develop the ability to quickly correct possible errors, through simple actions.
For this, devices are designed that prevent the continuity of production in the event of a failure along the way, preventing the customer from receiving a defective product .
An example: a team at Toyota repeatedly made the mistake of assembling switches without springs, preventing them from working correctly.
Engineer Shigeo Shingo, creator of the Poka Yoke, designed a simple change to the process: all the parts needed to assemble the item were now placed on the same plate.
Thus, if the operator forgot to install the spring, the error would be visible and the equipment would not be completed with the defect.
Kanban
Kanban means board . It is a system in which cards (similar to the famous post-its) are glued to a board.
It has two functions in one operation: instructing processes to manufacture products and instructing material handlers to move products.
The first is known as production or manufacturing kanban; the second is known as withdrawal or displacement kanban.
The objective is to enable the company’s production flows to be followed in a practical and visual way.
Today, there are several software and applications that digitally simulate this visual model , allowing interaction of the various users that make up the team.
Even so, the traditional Kanban, with the cards and the board fixed to the office wall, is still widely used.
Kaizen
Kaizen is another Japanese word, which means continuous improvement .
It is a mindset that was born within the Lean Manufacturing system and can be applied to any company, not just manufacturing industries.
Generally, kaizen improvements are small and incremental, but the kaizen process delivers results.
It emerged in Japan after the Second World War and led to impressive results. Its scope is wide and can be taken to all aspects of life, not just business.
It is based on two beliefs: everything can always be improved and small continuous changes generate long-term improvements.
The Kaizen methodology considers the following order of prioritization in improvement processes:
- Labor
- Method
- Material
- Machine.
Value Stream Mapping
Value stream mapping (VSM) is a tool that uses graphic symbols to document and visually present the sequence and movement of information, materials and actions that make up the value stream.
It is a simple diagram that aims to show all the steps involved in the flows of materials, information and people needed to serve customers, from order to delivery.
It is a macro view, which facilitates the identification of waste and bottlenecks in the production process.
How To Implement Lean Projects?
This article is packed with information.
Even so, it is quite summarized, because the Lean Manufacturing system involves many methodologies, techniques and concepts.
If you want to implement the ideas of the Toyota production system in your company, the first tip is to delve into the subject .
Start by reading Lean Thinking in Business: Eliminate Waste and Create Wealth , a book by James Womack and Daniel Jones that popularized the lean model.
From there, the implementation of the Lean Manufacturing system involves several steps, starting with in-depth evaluations.
Not just the current model, but the company culture .
After all, the Toyota system is not just a methodology, it is a philosophy that must be assimilated by all employees.
