Lean manufacturing is one of the most popular manufacturing techniques in the world today. Developed by Kiichiro Toyoda, founder of Toyota Motor Corporation, this process helps companies and manufacturers reduce waste.
So what is lean manufacturing? How it works? What are the principles and types of Lean Manufacturing? Read on as we provide answers to these questions and other important things about lean manufacturing.
What is lean manufacturing?
The lean manufacturing process, also known as just-in-time (JIT) production, dates back to the early 20th century. Toyota developed the Toyota Production System in the 1940s to minimize waste in its production method or process. The company developed three objectives that worked. The objectives are:
- Mining Overload (Muri)
- Eliminate inconsistencies (Mura)
- Avoid waste (muda).
However, eliminating waste in lean production does not mean reducing the workforce or creating drastic “shortcuts.”
It is important to note that the ultimate goal of lean production is not to eliminate waste, but rather to create sustainable value for customers. Lean manufacturing is a beneficial process because it reduces lead times and improves product quality and operating costs in the long run.
How does lean manufacturing work?
Lean manufacturing is the application of lean processes, tools and principles in the manufacturing or development of a product. It is a principle based on optimizing the product development process, eliminating waste, reducing costs, promoting innovation and reducing time to market.
Furthermore, lean manufacturing views waste as any process or production component that does not create value for the customer. Waste includes processes, products, activities or services that require money, time or skills but do not create value for the customer. Excess inventory, ineffective or expensive processes, and underutilized talent are also taken into consideration.
By reducing waste and improving production, lean production creates sustainable added value for customers.
5 principles of lean manufacturing
Five basic principles of lean production are used to implement lean. These principles include value, value stream, flow creation, pull system configuration, and perfection. Let's look at these principles in detail.
1. Value
Value is determined from the customer's perspective and refers to how much a customer is willing to pay for a particular product or service. It is the job of the service provider or manufacturer to create value by avoiding waste. When waste is eliminated, it becomes easier to balance the cost of the product with the price the customer is willing to pay for it, while maximizing profits.
2. Value stream
The value stream takes into account the entire life cycle of the product, from the acquisition of raw materials to disposal or recycling. This lean principle uses chain alignment to examine each step of the production cycle for waste and eliminate any processes that do not add value to customers.
Value stream analysis requires the joint effort of engineers, designers, scientists and all professionals involved in producing the product or service.
3. Create a flow
Lean manufacturing assumes that interruptions and disharmonies during production processes would disrupt flow and increase production costs. The principle of flow creation therefore involves the elimination of functional barriers in production that influence lead time. Removing these barriers would result in a smoother process flow, improving turnaround time and minimizing waste.
4. Set up a pull system
Lean production relies on introducing a pull system rather than the push system used in production resource planning. In push systems, inventory is determined in advance. Here, manufacturers configure production to meet forecasts and sales. However, the push system results in a lot of waste because most forecasts are inaccurate and often result in too much or too little production to meet demand.
A pull system, on the other hand, only works on demand. It is a flexible and efficient process whose success is based on optimal communication. As a result, teams that work with the pull system only start new tasks after the previous ones are completed. This allows teams to adapt to production challenges as they arise.
5. Perfection
Perfection is one of the key principles of the lean manufacturing process. Lean manufacturing involves continually evaluating production methods and processes to find a perfect system for the value stream.
This principle of perfection presupposes that continuous evaluation is accompanied by continuous improvement of manufacturing practices and processes. Metrics evaluated include production cycles, delivery times, cumulative flow and yield.
Types of waste in lean manufacturing
Eliminating waste in production is one of the basic principles of lean manufacturing. Waste is one of the main reasons for reduced profits in companies.
Lean manufacturing recognizes seven types of waste within a manufacturing process. Six of these wastes are related to the production system. The latter refers to the management of employees or workers.
1. Overprocessing
Refers to any unnecessary step in the production line or manufacturing process. It's a sign of a poorly designed process. Additionally, it could be due to poor communication, human error, overlapping authority, or data duplication.
This results in wasted material, labor, energy, time and gas emissions. A simple solution like process mapping can simplify the process to reduce waste.
Process mapping is a lean waste tool that can be used to eliminate unnecessary processes. This tool includes and guarantees the execution of production tasks, reporting, control and approval of documents.
2. Overproduction
Overproduction can lead to all other types of waste and, in most cases, excess inventory. This leads to greater consumption of raw materials and the possibility of the final product deteriorating during storage, resulting in waste.
One measure to combat this waste is to measure takt time, that is, the speed at which production must be carried out to meet customer demand. If cycle time can be reduced, the production process will run more efficiently.
3. Defects
Refers to products that do not meet customer expectations or design standards. A defective product must be replaced by another.
This affects time, customer satisfaction, money and resources. As a result, labor, materials used to produce the defective product, replacements, energy, time, etc.
To combat this, it is necessary to guarantee operational standards at all stages of the production line. This could mean more comprehensive and better documentation of design changes and the development of checklists to ensure compliance.
4. Inventory
This is due to unprocessed stock. This includes wasted inventory, capital, inventory transportation, containers and space used for inventory, storage costs, and more. This may indicate a broken procedural link between the procurement or planning of raw materials or products and the manufacturing process.
Excess inventory can also hide potential waste in the production of inventory. An effective solution to this waste is just-in-time production. There must be a balance in purchasing raw materials and products based on customer needs.
5. Transport
This involves transporting materials or products from one place to another. Furthermore, transportation does not add value to the product itself; This means you should minimize costs as much as possible. This can also mean that you have to wait for materials to start being produced, which is wasteful.
Cost minimization could involve locating production facilities closer or using more efficient transportation, such as larger trucks, to reduce the number of trips.
This would also reduce waste related to possible damage to the product during transport, transport packaging waste, energy consumption, exhaust gas emissions, etc.
6. Wait
Waiting is the time spent waiting for one production process to complete before moving on to the next. This increases costs for overtime, speeding up processes or machine parts.
Waste can also occur when workers try to beat time by taking shortcuts, which can lead to product defects. Management can resolve this by properly measuring the time required and changing the process design.
7. Unused talent
This type of waste occurs when management is unable to utilize all available talent. In most cases, this waste is due to poor management and poor communication between management and employees.
This causes management to assign tasks to employees that they are not trained to do or take on the wrong tasks. Management can achieve this through training opportunities and involvement in process improvements.
Advantages and Disadvantages of Lean Manufacturing
Lean production has several advantages and disadvantages depending on the area of application. Here are some pros and cons of lean manufacturing.
Benefits of Lean Manufacturing
Environmentally friendly
The lean manufacturing process is environmentally friendly because it reduces waste, which often leads to reduced fuel and energy consumption. It also promotes the use of energy-efficient tools and equipment for production, thereby reducing costs.
Saves money and time
One of the most obvious benefits of lean manufacturing is the ability to reduce production costs. Lean manufacturing promotes efficient and streamlined workforce and workflows, as well as proper allocation of resources, thus saving costs. Furthermore, using this manufacturing technique helps reduce lead time.
Greater customer satisfaction
Delivering a product or service at the right time and at the right cost increases customer satisfaction. And with lean manufacturing, manufacturers and service providers always strive to satisfy their customers.
Disadvantages of Lean Manufacturing
Places an embargo on future development
Lean manufacturing's focus on the present may limit future developments. The focus of lean manufacturing is on reducing waste, which could result in management eliminating areas of the business that are considered unimportant to the current production strategy.
However, in some cases these areas can be of great importance for the future development of the company.
Well-being and safety of company employees
The focus of lean manufacturing is on simplifying production processes and eliminating waste, and it often gives employees very little room for error. This increases employees' stress and pressure at work, which often has a negative impact on their well-being and safety.
Difficult to standardize
Lean manufacturing standardization is nearly impossible because it is more of a corporate culture than a defined production method or technique. Furthermore, because standardization is difficult, manufacturers consider this technology to be vague and loose rather than robust and functional.
What are the best lean manufacturing tools?
Lean manufacturing uses several tools and techniques to achieve a company's goals. The tool used generally depends on the environment and business objective. However, here are the best lean manufacturing tools.
Kanban
It is a digital or physical signal that triggers small batch production when necessary. Examples of this tool include a Kanban card and a 2-bin system.
Kaizen
The goal of this tool is to create small changes for everyone, every day, everywhere. It is an ideal tool for continuous improvement that takes into account the contribution of everyone involved.
Value stream analysis
It is a multifunctional tool used to trace, analyze and improve the flow of materials and information using a value stream. The value stream includes the complete set of activities required to maintain or produce a product from start to finish.
5S Management
5S consists of five disciplines: Sort, Organize, Shine, Standardize and Sustain. It is a productivity tool that makes deviations visible to increase efficiency.
Plan-Do-Check-Act (PDCA)
This is an important lean management tool, ideal for continuous improvement. This tool includes a comprehensive framework to easily identify and resolve issues.
The steps for using this tool include: making plans for a specific goal and doing the work necessary to make the plan a reality. This also includes reviewing the results of work performed and adjusting or correcting unsatisfactory results.
Practical Lean Manufacturing Tips for Machine Shops
Here are some practical lean manufacturing tips for machine shops.
1. Make sure your crafting system has a simple design
It's easier to monitor and improving systems is easy. Therefore, it is best to divide your production system into simple parts for easy evaluation and improvement.
2. Keep looking for opportunities for improvement
Always look for ways to improve your manufacturing process. It is also important that you encourage and support your employees to find better manufacturing methods and review the work being done to improve it.
3. Implement continuous design improvements
Striving for improvements is great, but implementing these improvements in projects and processes improves the business. It's also important to measure improvements and make small, incremental changes rather than large ones.
4. Seek support from the team
Without the support of your employees, implementing the tips above would be a difficult task. Therefore, you need to gain the support of your employees by informing them about the benefits of the lean manufacturing system.
WayKen Lean Manufacturing Capability
University Degree
Lean manufacturing leads to the creation of products with minimal waste. It is a technique that saves time and money by eliminating production processes that do not create value for customers. Applying lean manufacturing in a company is a way to obtain the best results.
Common questions
What is the fundamental principle of lean manufacturing?
The fundamental principle of lean manufacturing is to reduce waste while continually improving the production process.
What is the biggest benefit of lean manufacturing?
The biggest advantage of lean manufacturing is that it identifies and defines the causes of waste in a company and develops the best solution for them.
What are the rules of lean manufacturing?
There are four basic rules: structure each activity or event, clearly link each customer and supplier, define and simplify the workflow flow, and improve production processes through experimentation.
