According to Carreira, in his book,’ Lean Manufacturing that Works,’ he defines lean manufacturing or lean production is the optimal way of producing goods through the removal of waste and implementing flow, as opposed to batch and queue. Lean is about doing more with less time, inventory, space, labor, and money. Lean manufacturing is shorthand for a commitment to eliminating waste, simplifying procedures, and speeding up production. In its most basic form, it is the systematic elimination of waste (overproduction), waiting, transportation, inventory, motion, over-processing, defective units, and the implementation of the concepts of continuous flow and customer pull.
2.0 LITERATURE REVIEW
In the classical and neo- classical period, U.S. automakers responded to Japanese competition by retooling their factories to build smaller cars. They adopted successful Japanese methods, known collectively as lean production. Examples of this methods of production included increased automation, quality control (workers could stop the line to correct a problem, rather than marking it for future correction), and smaller, so-called just-in-time inventories (parts were delivered to workers on the line as they were needed, rather than in large, bulky quantities). This concept became more prominent with the manufacture of Toyotas by Japanese firms. Lean manufacturing is therefore a result of the generic process management philosophy that was derived from the Toyota Production system (TPS). Taiichi Ohno developed this concept in his book, ‘Toyota Production System.’ It is renowned for its focus on reduction of the original Toyota seven wastes in order to improve overall customer value. The steady growth of Toyota, from a small company to the most valuable and the biggest automotive manufacturer in the world, has focused attention upon how it has achieved this.
Just as mass production is recognized as the production system of the 20th century, lean production is viewed as the production system of the 21st century. For many, Lean is the set of “tools” that assist in the identification and steady elimination of waste. As waste is eliminated, quality is improved while production time and cost is reduced. The “tools” consist of value stream mapping, 5-S, Kan-ban (pull systems), and poka-yoke (error proofing).
The 5S Process, or simply “5S”, is a structured program that systematically aims to achieve total organization, cleanliness, and standardization in the workplace. A well-organized workplace results in a safer, more efficient, and more productive operation. It boosts the morale of the workers, promoting a sense of pride in their work and ownership of their responsibilities.
“5S” was invented in Japan, and stands for five (5) Japanese words that start with the letter ‘S’: Seiri, Seiton, Seiso, Seiketsu, and Shitsuke.An equivalent set of five ‘S’ words in English have likewise been adopted by many, to preserve the “5S” acronym in English usage. These are: Sort, Set (in place), Shine, Standardize, and Sustain.
In Lean Manufacturing, the main focus is upon improving the “flow” or smoothness of work, thereby steadily eliminating mura (unevenness) through the system and not upon ‘waste reduction’ per se. Techniques to improve flow include production leveling, “pull” production (by means of kanban) and the Heijunka box. This is a fundamentally different approach to most improvement methodologies, which may partially account for its lack of popularity.
The Heijunka box explains the principle of production levelling. A Heijunka box is a box with cells representing a specified duration. It is a visual scheduling mechanism that distributes the finishing schedule into small time increments. All production orders are set into the cells, according to scheduling. The operator of the leading process takes the orders from the cell corresponding to the actual time and processes the orders like scheduling set them up. This very simple system is also very flexible, as rescheduling is easy to do, exchanging orders in cells.
Basic Elements of Lean Manufacturing are waste elimination, continuous one-piece workflow, and customer pull. When these elements are focused in the areas of cost, quality, and delivery, they form the basis for a lean production system.
The lean production concept was largely inspired by the Kaizen – the Japanese strategy of continuous improvement. Employee empowerment, imitation of customer relationships, fast product development and manufacturing, and collaboration with suppliers are the key strategies of leading lean companies.
Several methodologies should be applied, to enable a lean approach in any given organization. They include:
• Specifying Value. Value is defined by the ultimate customer’s needs through tools such as value management, quality function deployment and simulation.
• Identifying and Mapping the Value Stream. The value stream identifies all those steps required to make a product. Identifying value stream, the way value is realized, establishes when and how decisions are to be made. The key technique behind value stream is process mapping for a very specific reason: that of understanding how value is built into the building product from client’s point of view.
• Establishing Flows. Flows are characterized by time, cost, and value. Resources (labor, material and construction equipment) and information flows are the basic units of analysis.
• Pull. At a strategic level, this identifies the real need to deliver the product to the customer as soon as he needs it.
• Achieving Perfection;. It refers to constantly considering what is being done; how it is being done and harnessing the expertise and knowledge of all those involved in the processes to improve and change it. With continuous improvement done and with waste eliminated along the flow process, perfection is the ultimate sweet reward that companies can achieve
4.0 DATA ANALYSIS
When the following methodologies are applied, an integrated single piece continuous workflow would be obtained, there would be Close integration of the whole value chain from raw material to finished product through partnership oriented relations with suppliers and distributors, a Just-in-time processing will be in place. JIT processing refers to a situation when a part moves to a production operation, is processed immediately, and moves immediately to the next operation. Lean management would also result to Short order-to-ship cycles times which refers to small batch production capability that is synchronized to shipping schedules
The application of these methodologies would also result to a situation where production is based on orders rather than forecasts; production planning is driven by customer demand or “pull” and not to suit machine loading or inflexible workflows on the shop floor. It would also result in minimal inventories at each stage of the production process as well as ensuring that Layout is based on product flow
Lean production enhances Total quality control i.e. there’s an active involvement by workers in trouble shooting and problem solving to improve quality and eliminate wastes.
Every organization should strive to apply the lean production process in its day-to-day operational and managerial activities. Benefits that accrue from lean production include:
· Waste reduction by 80%
· Production cost reduction by 50%
· Manufacturing cycle times decreased by 50%
· Labor reduction by 50% while maintaining or increasing throughput
· Inventory reduction by 80% while increasing customer service levels
· Higher quality
· Higher profits
· Higher system flexibility in reacting to changes in requirements improved
· More strategic focus
· Improved cash flow through increasing shipping and billing frequencies
1-Production Capacity increase
4-Production cost Reduction
According to a study conducted by GE (general electrics), successful companies practice the following:
1. Manage processes, not people. Focus not on what they do, but on how they do it.
2. Use techniques (like “process mapping” and “benchmarking”) to achieve continuous improvement.
3. Value incremental gains.
4. Measure performance by customer satisfaction.
5. Introduce new products faster that the competition.
6. Design new products for efficient manufacture.
7. Treat suppliers and customers as partners.
Lean techniques are applicable not only in manufacturing, but also in service-oriented industry and service environment. Every system contains waste, i.e. something that does not provide value to your customer. Whether you are producing a product, processing a material, or providing a service, there are elements, which are considered ‘waste’. The techniques for analyzing systems, identifying and reducing waste and focusing on the customer are applicable in any system, and in any industry.
Lean thinking may also be applied in getting rid of bureaucracy in your home office. To run your home office more effectively and faster you may need just as little as 10% of its current staff. Only executives who have a direct involvement with finding, keeping, or growing customers as well as key support staff – accountants, tax, legal and human resources people – should stay. Others can be rehabilitated by sending to an operating unit.
There are some shortcomings associated with lean production. They include reduce variability and uncertainty in the supply chain as well as longer flow times and reduced throughput, and potentially reduced economic performance.
Despite all these, Lean production is good for any given company since it improves a company’s efficiency and effectiveness. It reduces the costs of production at the same time ensuring that quality goods are provided to consumers. This on the other hand makes the company very competitive in the market as well as profitable.
Meyer, Christopher: Relentless Growth. Oxford University Press, 2003.
Nicholas John M. Competitive Manufacturing Management. New York University Press, 2004.
Bill Carreira. Lean Manufacturing that Works. Harvard University Press, 2002.
Taiichi Ohno. Toyota Production System. Oxford University Press, 2003
Jeffrey Liker. The Toyota way. Greenwood, 1993.