Originated in the Toyota car manufacturing company, Lean production is an approach designed to optimize value adding processes and eliminate inefficiencies known as “waste.” These waste contribute to higher costs, decreased productivity, and lower quality output thus affecting business performance.
The seven lean waste categories, also known as “MUDA” in Japanese and lean manufacturing, happen to be the focus areas for businesses aiming for enhanced operational efficiency.
This article talks exclusively about the 7 wastes of lean manufacturing in production and ways to reduce or eliminate them. So, let’s get it rolling.
7 Wastes of Lean Production
Here’s the list of the lean waste categories.
1. Overproduction
This waste is one of the biggest contributors to inefficiency in manufacturing. Overproduction occurs when more goods are produced than are actually needed or produced ahead of time to fill up the finished goods warehouse. It’s a major issue as it leads to unnecessary utilization of resources, increased storage cost, and of course production of waste.
For instance, a factory produces 10,000 units without any confirmed orders. This way, it not only utilizes raw material to complete the production order, but requires storage space as well. Excessive production can also result in product obsolescence and the need for discounts to clear the stock. This ultimately impacts profit margins of the manufacturing plant.
According to the latest studies, overproduction can account for up to 30% of total production costs in traditional manufacturing environments.
2. Inventory
The storage of excess products or raw materials that are not actively being used in production is called inventory waste, while it’s necessary to have some level of inventory to meet the demand, excessive inventory results in additional costs for storage, lighting, heating and cooling, as well as increased risk of stock losses and damage. These losses increase the cost of doing business unnecessarily
Lean manufacturing principles advocate for maintaining only the minimum inventory required to meet demand. Studies have shown that companies using lean strategies such as JIT production, statistical analysis of sales demand, forecasting and EOQ have reduced their inventory levels by 20-30%, freeing up space and reducing wasted resources.
3. Transportation
Transportation waste is the unnecessary movement of materials or products between different locations within the production line or the supply chain. Despite adding value to the product, unnecessary transportation leads to increased costs, longer lead times, and potential damage during transit. For example, moving raw materials from one end of the factory to another or shipping a product through multiple storage or distribution facilities before reaching the customer only adds inefficiency.
Research pinpoints that businesses employing lean methodologies such as value stream mapping have seen up to a 25% reduction in transportation costs by optimizing material flow and eliminating unnecessary movements.
4. Motion
Motion is a waste that refers to the inefficient or unnecessary movements of workers or equipment. This includes employees walking across the factory floor to retrieve tools or equipment being set up repeatedly in various locations without any thought to their application and use. Such movements not just waste time but also contribute to worker fatigue and injuries.
Unnecessary motion has been observed to reduce worker efficiency by 5-10%. A Lean system, therefore, aims to design workflows and plant layouts that minimize movement and allow tasks to be completed seamlessly with little wasted time and movement. This keeps the workstation organized and efficient.
5. Waiting
Waiting occurs when employees or equipment are idle because materials, instructions, or other resources are unavailable for them to continue or finish a task or product. This results in a bottleneck in the production process and significantly reduces overall productivity. For instance, assembly line workers may be forced to wait for parts or instructions, delaying production and output of the factory.
Waiting times can reduce productivity by 15-20% or even more depending on the type of delay and setup of the production line, according to surveys. Efficient scheduling, improved communication, and better resource planning and management can play a lead role in reducing this sort of waste.
6. Overprocessing
Overprocessing can lead to a 10-15% increase in production costs. This type of waste involves performing more work than necessary to meet customer needs. This might include using higher-grad materials than required, adding unnecessary steps to a process, or applying additional features that don’t add value to the final product or that the customer is willing to pay for.
Companies that practice lean manufacturing regularly review their processes to eliminate unnecessary tasks and ensure each step adds value to the end product.
7. Defects
Any product or service that fails to meet quality standards, resulting in rework, scrap, or warranty claims falls in the category of waste known as defects. This waste increases production costs besides damaging a company’s reputation and customer satisfaction and brand perception for the business.
Defects are found to be responsible for up to 10% of total production costs in some industries. Implementing rigorous quality control measures and fostering a culture of continuous improvement are necessary steps to reducing defect waste.
Tips for Reducing and Eliminating the 7 Wastes
Here comes the best part, what to do to address these wastes in your business?. Although these wastes happen regularly, these can be reduced or eliminated by practicing lean manufacturing tools and improvements.
Let’s dissect the tips and hacks to overcome these problems and increase production efficiency.
1. Reducing Overproduction
| Implement a pull system |
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| Improve forecasting |
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| Increase production flexibility |
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2. Managing Inventory Efficiently
| Just-in-time inventory |
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| Use real-time inventory tracking |
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| Collaborate with suppliers |
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3. Optimizing Transportation
| Redesign plant layouts |
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| Consolidate shipments |
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| Use local suppliers |
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4. Minimizing Motion Waste
| Ergonomic workstations |
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| Apply the 5S system |
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| Workflow analysis |
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5. Reducing Waiting Time
| Improve scheduling systems in production |
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| Cross-train employees / multi skilling |
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| Automate where possible |
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6. Reducing Overprocessing
| Conduct value analysis |
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| Standardize processes |
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| Customer feedback |
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7. Reducing Defects
| Implement quality control systems across the supply chain |
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| Root cause analysis and rectification |
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| Invest in employee training |
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Conclusion
Lean manufacturing emphasizes the importance of eliminating the 7 wastes of lean manufacturing. Also known as Muda in Japanese, lean manufacturing identifies 7 types of wastes as overproduction, inventory, transportation, motion, waiting, overprocessing and defects. By addressing each type of waste through proven strategies like JIT, ergonomic workstations, and robust quality control measures, businesses can reduce costs, increase efficiency, and improve overall product quality.
