Lean manufacturing is an approach that uses five main principles in order to determine the value of a particular product, to identify and ensure its flow value creation, to allow consumers to extract the product as well as companies to seek excellence. The concept of lean manufacturing was created in the mid-twentieth century as an attempt to solve the problem by creating a new production system for enterprises that were built on the principles of mass production but were forced to exist in the modern competitive environment. Thus, manufacturers have combined the need to release a wide range of products and, at the same time, to provide a flexible response to constantly changing demands of consumers. It created the need for the new method such as lean manufacturing.
Keywords: lean manufacturing, value, competitiveness, jidoka
Managers always try to increase the competitiveness of the enterprise at the minimal cost. One of the most innovative approaches to management such as lean manufacturing helps solve this problem today (Lean Production). It is based on the principles of the production system of Toyota (Toyota Production System) (Roser, 2016). The ideas and methods of lean production are aimed at detecting and removing all kinds of production losses, culture change management, and the system of value orientation of employees. The principles and tools of lean manufacturing are universal, therefore, they can be used by companies of any size and in any industry. The essay gives summaries of new studies in lean manufacturing and researches the fact that the production according to the principles of lean manufacturing allows companies of different industries to achieve operational excellence.
History of Lean Manufacturing
C. Roser in his book “Faster, Better, Cheaper” In the History of Manufacturing: From the Stone Age to Lean Manufacturing and Beyond (2016) highlights the history of lean manufacturing in various industries. The author states that the term “Lean Production” was first used by John Krafcik in 1988 as referring to the type of production in which nothing was superfluous (Roser, 2016). The creator of lean manufacturing Taiichi Ohno began the first experiments to optimize production back in 1950. In those post-war days, Japan lay in ruins and the country needed new cars (Roser, 2016). However, the problem was the lack of demand to justify the purchase of an expensive product line, such as Ford. The country required many different types of vehicles (cars, small and medium trucks, etc.), but the demand for a particular type of machine was small. The Japanese had to learn to work effectively, creating distinctive models in conditions of low demand for each of them. This problem was not solved as efficiency was understood only in terms of mass production. Therefore, John Krafcik, one of the American advisers, invented the lean manufacturing as the system that could effectively create many kinds of products at low unit costs and was called lean or “saving” (Roser, 2016). The idea to move to lean manufacturing was proposed by James Womack (the founder and the president of the Lean Enterprise Institute) and Daniel Jones (the founder and the chairman of the Lean Enterprise Academy) (Womack, & Jones, 2003).
The Main Concepts
Eric Tharp in his book Lean Manufacturing (2011) explains the main concepts of the system. The production system had two “pillars”: the system of jidoka and “just in time system”. Jidoka means “pull”, that is, the idea on which the next production stage asks desired products from the previous one, but until that happens, nothing is produced. The consultants have identified the concept of lean manufacturing as a plurality of elements, each of which represents a particular method and some (such as Kaizen) themselves (Tharp, 2011). It created the status concept:
- The system TPM (Total Productive Maintenance) means general care facilities.
- 5S System (sort, follow the procedure, keep clean, standardize, improve).
- Fast changeover SMED (Single-Minute Exchange of Dies (literally “quick-change molds” meant changeover / upgrading of equipment in less than 10 minutes). One touch changeovers (One-touch setup), that is the version of SMED, but the time changeovers are measured units of minutes).
- Continuous improvement.
- Continuous improvement of on-site value added.
- Systems of ejection – products are pulled by the customer, not pushed by the manufacturer. Informing the previous production stage that should begin work.
- Just in time system – the timing system that transfers product from one production stage to another. Components must be transmitted to the next stage only when necessary, and not a moment before.
- Protection against error – the method of preventing mistakes, a special device or method by which defects cannot just appear.
- Point lean production – the creation of value for the consumer (Tharp, 2011).
Thus, all that does not add value for the consumer in terms of lean classified as a loss that should be removed.
The Set of Subsystems and Instruments
John X. Wang in his publication Lean Manufacturing: Business Bottom-Line Based (2011) stresses that the lean production system offers the broadest set of subsystems and instruments. They help successfully increase the production efficiency. The main advantage of this approach is not specific methods or techniques but their entirety. The system of lean thinking is defined as a single mechanism of continuous improvement. This approach allows enhancing all business processes so that the company achieves sustainable growth and continuous efficiency.
The Main Idea of the Lean Production System:
– Consideration of action in terms of creating value for customers.
– Combating activities that do not create value.
– Reducing the time from order placement to product delivery to consumers.
– Elimination of hidden losses production.
– Continuous improvement of production and creating an organization where learning is permanent (Wang, 2011).
Moreover, the author considers that the main features of lean manufacturing are:
- Production Management: The production cycle time is regulated precisely relevant to the existing demand.
- Planning of Work: Components of preliminary operations “stretch” system if necessary, determine priorities of production sequence stretching.
- Company production: Reduced time of readjustment, which allows small parties to work quickly readjust to a different product.
- The order: the dispatch of orders of any size and nomenclature.
- Culture Management: Management prevents reasons that cause difficulties.
- The approach to solving problems: How to fix the situation?
- Leadership: Master.
- Attitude to staff: Staff affects the effectiveness of the results (Wang, 2011).
John X. Wang also explains the philosophy of lean manufacturing. It is based on the provisions that define guidance for managers:
- The definition of the value of each product from the customer’s perspective.
- Identification of all phases’ flow creating relevance for each product and elimination of actions that do not create value.
- Develop operations that create value in the strict sequence. This ensures smooth movement of the product in the stream sent to the client.
- The authors emphasize that after the formation of the flow, creating opportunities for pulling the consumer products from the previous stage is important.
- Continuous improvement should also be noted. The company that began to eliminate loss of flow processes would see that the process of improvement to happen. Moreover, each time it is necessary to increasingly reduce the time of action, cost, production sites, and damage (Wang, 2011).
Hidden Losses in Production
J. R. Henry in his book Achieving Lean Changeover: Putting SMED to Work (2013) proposes major types of losses that can be found in the production:
- Excessive production ahead or large quantities of whatever is required for the next production stage or the client.
- When the work is associated with the expectation of materials, tools, information, equipment, etc. It often occurs due to the malfunction of equipment or untimely receipt of the necessary details, flaws in planning, and other reasons.
- Unnecessary moving of the parts and products. For example, the product is transported from production to the warehouse, even though it is possible to immediately give details of the work to the next production stage.
- The implementation of unnecessary or incorrect treatment, usually because of the poor quality of the instrument, ill-conceived imperfect technology or product design.
- Defects and defect fixes. This loss is related to inspection and identification of defective products, recycled products to correct defects.
- Implementation of operators’ movements that go beyond productive or are of no need, for example, the search for parts or walking tool.
- Storage of raw materials or semi-finished products in larger quantities than needed to work according to the accurately planned production system (Henry, 2013).
According to the author, the main types of losses can be classified as:
- Losses due to overproduction;
- The loss of time due to expectations;
- Unnecessary losses during transportation;
- Losses due to the extra processing steps;
- Losses due to excess inventory;
- Losses due to unnecessary movement;
- Losses through the issue of defective products;
- Designing products that do not meet the needs of consumers (Henry, 2013).
The Value in Lean Manufacturing
R. B. Lopes., F. Freitas, and I. Sousa in their article “Application of Lean Manufacturing Tools in the Food and Beverage Industries” (2015, October 7) explain that the nature of the lean production is a specific interpretation of the concepts of value and loss. Accordingly, every action of the material, detail or document is viewed from two sides: what value this approach creates for end users and how to minimize activities that do not create value for the consumer, i.e. to reduce losses. The value of employing this method can determine the usefulness of the inherent product from the customer’s perspective. The value is a set of properties for which the buyer is willing to pay the money by buying the product. It is manufactured in a series of steps, some of which create value from the customer’s perspective. Another type of action does not create value, however, it is performed in accordance with the existing organization of the production process. Producers have a simple way to determine whether the value is created as a result of a particular action: they can ask the client whether he would consider a less expensive product if this action is performed. Conversely, they ask whether the buyer is ready to pay for the implementation of a particular operation. Undoubtedly, the consumer is unlikely to recognize that repeated corrections or prolonged lack of warehousing increases the acquired value of the product. The purpose of the concept of lean manufacturing is to eliminate the flow of the production activities that consume resources instead of creating value. Thus, the authors stress that it is also important to increase the effectiveness of actions that create value (Lopes, Freitas, & Sousa, 2015, October 7).
Evaluation of the References
To my mind, C. Roser in his book “Faster, Better, Cheaper” In the History of Manufacturing: From the Stone Age to Lean Manufacturing and Beyond (2016) gives a profound explanation how the idea of lean manufacturing has been developing. Eric Tharp in his book Lean Manufacturing (2011) explains that the method needs the multitude approach to manufacturing actions. John X. Wang in his book Lean Manufacturing: Business Bottom-Line Based (2011) has explained readers the philosophy of the lean manufacturing providing the explanations of new methods of production organization. J. R. Henry in his book Achieving Lean Changeover: Putting SMED to Work (2013) has highlighted the types of losses that can be found in the manufacture; I consider this book useful for the managers. It was also interesting for me to get acquainted with the application of lean manufacturing in the industry that was described by R. B. Lopes., F. Freitas, and I. Sousa in their article “Application of Lean Manufacturing Tools in the Food and Beverage Industries” (2015, October 7).
It is safe to assert that the introduction of lean manufacturing helps to create the system of organization and management of product development, manufacturing operations, relationships with suppliers and customers, in which products are manufactured in strict accordance with the needs of consumers and with fewer defects. It reduces the cost of labor, capital and time, declining industrial areas. Without the change in output, the system of lean manufacturing usually requires twice fewer labor costs, half the size of production facilities and investment, several times less time to develop new products and order fulfillment. The production is made of smaller parties, and there are reduced defects as well as the percentage of the volume of stocks.