Lean Manufacturing is a management strategy that strives to increase productivity while minimizing waste and keeping quality in control. Based on the principles of small and continued improvement, you can only achieve lean manufacturing by following a carefully thought out roadmap. However, to put a plan into action, you need to understand its core principles.
Lean manufacturing principles originated from the manufacturing technique that was spearheaded and perfected by Toyota. Also known as "just-in-time production," this process enabled the car manufacturer to transform and master the method of manufacturing vehicles.
The thing about lean manufacturing principles is that it is not based on investing in state-of-the-art infrastructure, but designing a mental approach that is needed to work with optimal efficiency. This plan of action is suitable for businesses of all sizes as its implementation is not an expensive investment.
Lean treats the manufacturing process as a journey that thrives on continuous improvement. Once you take the first step, following all the way till the end makes the manufacturing process easier and prolific.
Let us discuss the seven key principles of lean manufacturing.
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1. Reduction of waste
The core tenet of lean manufacturing principles lies in reducing or eliminating wastage. In manufacturing process, there are seven kinds of waste.
Let us talk about each in detail:
- Excessive production: overproduction is bad news for a production process. It is about producing an item before it is even needed. Producing more than required inhibits a uniform flow of resources and also impacts the quality, not to mention productivity. Toyota Production System introduced "Just-in-time" to create products as needed. The idea is only to produce what can be immediately sold.
- Waiting time: in the production flow, a lot of wasted lead time is in moving to the next level and usually happens when there is machine downtime or shortage of material. However, by implementing a standardized workflow, any wasteful lag will be immediately noticeable.
- Transportation waste: when the product needs transportation within the process, it only adds up to the cost without adding any value to the product or the customer. In fact, extreme handling or movement of the product can cause damage or decrease its quality. Organizations must map their product flows to build processes that are linked closely to one another.
- Overprocessing: Sometimes all you need is basic infrastructure to make high-quality products. Companies often make the mistake of investing in sophisticated equipment when simpler tools could do the job. This leads to overproduction as the company tries to recover the cost of machinery by producing more. It is recommended to use smaller equipment and create proper plant layout to prevent the wastage arising out of unsuitable processing.
- Excessive Inventory: when there is more inventory than necessary, it tends to mask the problem on the shop floor. This issue often gets ignored or overlooked as it is hidden within a process. However, it is important to identify, and the fix the problem to improve production. A steady flow between departments has helped many manufacturers in reducing excess inventory and thereby controlling associated expenses.
- Wastage of Unnecessary Movement: Toyota Production System realized that any movement that does not contribute to the production is wasteful. Unnecessary stretching, lifting, walking or bending are all related to excess motion. Plants that involve jobs with excessive movement are not only a wastage but also a health and safety hazard. The aim should be to keep the changes small, and the plants should be designed keeping ergonomics in mind.
- Waste of Defects: defective products can impact the company's revenue by adding rework costs to the total cost of production. In many businesses, defective products constitute a substantial portion of production costs and is the reason why lean focuses on quality over quantity.
Even though all types of waste mentioned above are specific to manufacturing, the same principles can be used in the other business areas as well. Elimination of waste requires a comprehensive review of all the systems and determine all the areas that are not adding value to the process. Once identified, these elements must be eliminated from the process, to make things smoother and more efficient.
2. Seeking Kaizen – strive for perfection
Lean manufacturing principles are designed to improve efficiency and seek constant improvement. Kaizen, also known as continuous improvement, is one of the most important lean principles. If you are planning to implement lean, then growth should be your core focus or your evolvement will cease at some point. It is not just important to introduce progress at the manufacturing level but throughout the organization. It is not so much a process as it is a mindset.
Lean thinkers always want to improve every component of the value stream. You will hardly ever hear a lean manufacturer being satisfied with what they have today. It is their attitude to continuously analyze, evaluate and involve their employees in the improvement process that helps the company grow. It is only when you seek perfection will you be able to identify and fix problem areas and improve your product quality.
3. Defining the sequence
Value creation is not just on paper. If you need to make a difference, you need to implement the lean principles into your manufacturing ecosystem. This implementation requires a smooth flow. For the production to happen with utmost fluidity, it requires being done in sequence. It is only through this flow will you achieve flawless movement between output and product's final delivery. The goal here is to find continuous and well-orchestrated production systems. This can be accomplished by mapping all the steps involved from customer order to product delivery.
4. Respect your Employees
It is the employees of an organization that can make or break its processes. The people in your company are your most vital resources. Your business will never to be able to scale heights without the hard work and contribution of its people. Lack of respect for employees can discourage them from performing at their optimal efficiency. This can be one of the biggest hindrances in an implementation of lean.
Everyone in an organization wants to feel like a significant part. They want to make noticeable contribution to company's growth and want to be acknowledged for their hard work and diligence. In absence of respect and rewards for their effort, the employee loses his will to do their part.
Respecting employees, at an organizational level, necessarily means that you will be attentive to their needs, listen to their problems, hear their opinions and encourage them to be a part of the organization's advancement. Empathizing with your employees will go a long way in earning their trust and loyalty. There should always be an open channel of communication between you and your workers. Empower them with responsibilities so that they can feel accountable for all the things that go right or wrong within the organization.
5. Uniform Levels of Production
In lean manufacturing terminology, this means that the same number of units should be produced every day. It is very important to have standardization in a production facility. The basic idea stems from the fact that your customer orders will not remain the same forever. They will fluctuate based on their needs. Someday they need 3 parts and other days they would need 7 or 10 parts. The fact is that the numbers will keep changing. However, uniform production is useful in ironing out the modification.
The organization can set the volume of production based on projections and forecasts. You can also study previous customer orders to understand the variation in customer demand and adjust your volumes accordingly. By implementing this principle, you can maximize the efficiency of your production units and reduce excessive overtime, in case there is a request for more orders.
With uniform production, you will be able to reduce the inventory levels as well as wasteful consumption of raw materials as you are only producing what is needed. Most importantly, you will be able to develop standard production schedules that will allow you to plan things in advance.
6. Just-in-Time Production
This is one of the most crucial components of lean manufacturing and any company's primary goal, who is planning to introduce lean into their production process. The concept of JIT is based on a premise that only those quantities will be produced that are required. In an ideal Just-in-time facility, there will be no finished goods as they will only be built real time when ordered by the customer. However, in real world, this is not possible as customer orders fluctuate all the time.
7. Build Quality In
By integrating quality as a lean principle, production process will be able to reduce defects and rework cost. Poor quality is the major cause of wastage. There is waste in not only defective products but also in fixing the errors and unsalvageable items. However, by building quality into the design of manufacturing process, you will be able to make it inherent to the final product. When you build quality into manufacturing, it can be integrated into every aspect of product, from design to shipping.
By implementation of these simple principles, any organization will be able to gain tighter control over their production processes and eliminate waste at the same time.