Lean production is a production approach by streamlining operations and processes to reduce waste, maximize productivity, and improve efficiency. In addition, companies adjust production systems to reduce setup time and promote better scheduling. Also known as flexible manufacturing technology or lean manufacturing.
Lean production strives to minimize wasted resources and improve quality control at every stage. In addition, it seeks to reduce the time within the production system and the response time from suppliers and customers.
In general, lean production aims to achieve the following:
- Zero delay
- Zero inventory
- Zero defects
- Zero waiting time
- Zero accidents
Waste is not only related to output. I mean, it’s not just because the product is damaged or defective and has to be thrown away or reprocessed. But, it is also related to:
- Human effort
Minimizing waste and reducing waste is done not only by using resources as efficiently as possible. But it also does so by removing unnecessary or non-value-adding processes.
- Lean production focuses on the following processes:
- Inventory control and replenish supplies only when needed
- Empower employees to support more efficient processes
- Minimize defects to reduce time and effort to inspect or repair items
- Capacity optimization, should not be underutilized or overutilized
- Maximize resources and should not be wasted
- Arrangements and scheduling for time efficiency and minimizing machine or people movement
Lean manufacturing relies on continuous improvement, flexibility, quality control, and reliable system-integrated supply chain management. It is done by applying the principles or methods below:
- Just-in-time (JIT)
Principles in lean production
Lean production seeks to reduce the time needed to ship incoming materials, process materials into products, and make products available to consumers. Moreover, it emphasizes process mapping to identify value-added activities. The company then eliminates some other activities if they do not contribute to adding value to the product, either directly or indirectly.
Several principles in lean production are as follows:
- Waste minimization
- Employee empowerment
- Worker flexibility
- Fast communication channels
- Continuous improvement
- Supply chain management
- Visualize workflow
- Focus on the flow
Lean production benefits
Lean production reduces costs with efficiency in the production process. Take the example regarding supplies. The company will only keep the needed stock related to supplies for raw materials, components, and finished goods. Thus, related costs such as warehousing and activities can be minimized. Likewise, effort and labor can be allocated to other, more essential activities.
Lean production offers other benefits, including:
Zero defects. Lean production seeks to minimize defects. Thus, there is no need for replacement or follow-up inspection, which is costly and time-consuming. This principle also increases customer satisfaction.
Less money tied up in inventory. The company supplies materials only when needed. Thus, only a tiny amount will be stocked, allowing less money to be tied up in supply.
Save time by eliminating unnecessary activities. The company maps the production system and divides it into several jobs or tasks. Each contributes to providing added value to the product, directly or indirectly.
Little accident at work. Lean production minimizes machines and workers moving around the factory. Thus, it contributes to improving occupational health and safety.
Methods in lean production
Kaizen is the Japanese term for continuous improvement. It involves forming small teams to drive continuous improvement, leading to more productive and effective production processes. The team identified the changes and improvements needed to drive continuous small improvements.
The Kaizen principle encourages everyone to take many small steps to improve systems before problems arise. Improvements are not made episodically but continuously. It involves everyone.
Kaizen adheres to the following principles:
- Processes, people, and organizations can constantly be improved.
- Small, continuous improvements are better than one big change.
- Change is necessary if it is to lead to improvement, so people need not be resistant to it.
- Focus on improvement reduces waste, wastage, and, ultimately, costs.
The company empowers employees to successfully run Kaizen. For example, they encourage employees to quickly bring issues to management without bureaucracy or communication barriers.
Employees are the best people who know how a task should be done. Therefore, they should be responsible for understanding how their work can be improved, both efficiency and quality.
Employees collect new ideas about their work. It is then processed to a further stage where small groups meet regularly to discuss their ideas, including discussing problems in their work and possible solutions to those problems.
Moreover, Kaizen eliminates waste by eliminating unnecessary movement in the workplace. It was also done by fixing the factory layout. Thus, it frees employees from unnecessary work.
The ideas in Kaizen work well under the following conditions:
- Employees must be empowered and directed to make necessary improvements in their areas.
- A teamwork culture must be built within the organization to foster new ideas and encourage them to work together.
- A democratic style is needed to encourage employees to voice their issues freely.
- Employee engagement must be increased no matter how small their contribution is.
Just-in-time (JIT) is an inventory system designed to reduce inventory holding costs. The company supplies goods only when needed.
Thus, unlike in just-in-case where firms hold high stocks as buffers, JIT does not require buffer stocks. Instead, it relies on timely delivery. The company will supply raw materials and components to arrive at the manufacturing plant when needed to enter the production process.
JIT views inventory control alone as insufficient. Holding inventory can lead to waste, in which a company’s money is tied up in inventory and can’t be put to better use elsewhere. Thus, JIT provides solutions by managing flows more integrated, including those related to raw materials, work in progress, and finished products.
Effective JIT supports lean production by minimizing inventory and ensuring flow throughout the production process. It requires companies to ensure purchasing, production, and shipping to customers have a coordinated flow.
JIT contributes to minimizing inventory costs and reducing waste. In addition, this method offers several other advantages, including:
- Improve relationships with suppliers by communicating actively for procurement and delivery.
- Flexibility in production, allowing companies to be more responsive to changes in customer demand.
- Save on rental and insurance costs associated with shipping and warehousing.
- Less working capital is tied up in inventory because it holds inventory only when needed.
- Fewer opportunities for obsolete or damaged raw materials or components from stockpiling in warehouses
However, implementing JIT can be a challenge. Companies must ensure their suppliers are reliable. So, they can quickly fulfill orders. They immediately send materials to go into the production process at the factory. Other drawbacks are:
- More susceptible to system or production schedule disruptions if one or two inputs do not arrive on time.
- Increased administrative costs and work as companies order more frequently.
- Challenges to meet unexpected demand because the company produces only when there is an order.
Kanban is a production approach where timely stock control is applied to bring inventory into production when needed. First, companies record the supply and use of inputs. Then, the company builds a reliable scheduling system to align inventory levels with consumption in production systems.
Kanban is a card-based system where labels visually represent aspects of the production process. A label will be affixed to the Kanban board to visually show the production system and its parts. It is also to show where each component is at any given time. So, team members can see the status of each piece of work at any time.
Kanban reduces waste. In addition, it contributes to improving system flow and increasing flexibility in production.
However, kanban also requires perfection, and there is no room for error. Therefore, if demand fluctuates significantly, it can cause problems because the system can’t accommodate it. In addition, a quality problem or a defect is challenging to solve because there is no buffer stock.
Andon is a visual system to show production status. It notifies workers if a problem occurs, perhaps related to quality or processing. For example, when workers turn a signboard red, it indicates a problem is occurring.
Andon provides alerts in real-time. So, the team can immediately take corrective action. It is usually used when personnel are far apart from each other or handle many different machines.
But, to run it successfully, companies rely on responsible operators. They also need the training to use the Andon system.
Cradle-to-cradle design and manufacture
Cradle-to-cradle is a design and manufacturing approach to eliminate waste and support a sustainable production system. It requires cautious thought.
Companies design and product design with the entire product life cycle in mind. As a result, they had to rethink every step in production to ensure everything was well-spent. They must also ensure components are fully biodegradable and non-toxic.
Production involves input and output as nutrition:
- Technical nutrients – can be recycled without losing quality.
- Biological nutrients – can be consumed or composted.
The company tests every chemical or raw material and output to ensure they are safe for humans or the environment.
Cradle-to-cradle has several features, such as:
- Rely on environmentally friendly materials
- Reusing materials
- Using renewable energy
- Use water efficiently
- Be socially responsible