Chapter-Two-Lean.pdf
- 1. Wollo university Kombolcha Institute of Technology School of Mechanical and Chemical Engineering Department of Industrial Engineering New production Concepts Chapter-Two Lean, Practice, and Implementation By: Mengistu.M Wollo, Kombolcha Augest,2022
- 2. Objective and Outline Understand the term lean Define types of lean waste understand the 5 Key Lean Manufacturing Principles Define and understand waste minimization lean tools.
- 3. History of lean The lean manufacturing (LM) or Toyota Production System (TPS), pioneered by a Japanese automotive company, Toyota, has been implemented by nearly all countries across the word due to its global superiority in cost, quality, flexibility and quick respond. Lean is a production practice that aims to minimize waste with entire value streams creating more value for customers. The main purpose of implementing lean manufacturing is to increase productivity, reduce lead time, cost and improve quality thus providing the up most value to customers.
- 4. What is lean ? Lean is a systematic method for the elimination of waste (“mudu”) with in a Manufacturing system. Lean also takes into Account waste created through overburden ("muri") and waste created through unevenness in Workloads ("mura").Lean manufacturing is now one of the most powerful manufacturing systems in the world. The “Lean” principle has often successfully implemented in companies to achieve considerable savings in production line by means of improving the efficiency of the production process.
- 5. The objective of Lean manufacturing is to minimizing the wastes and to adding more value to the existing process so that the system performance has been improved significantly. Lean manufacturing tools mainly focuses on reducing all types of wastes within the manufacturing process which will improve the manufacturing lead time and also the product quality.
- 6. Steps of lean manufacturing implementation 1. Identification of wastes in the system: Many organizations need to know that they have many hidden and unhidden wastes in their systems. 2. Wastes present in the organization can be of d/t types There is a need to recognize the types of waste and their causes. Lean manufacturing believes in treating the causes and curing the problems permanently. There are various tools and techniques that are quite helpful in reducing or eliminating these types of waste.
- 7. 3. Find the solution for the root causes . One must stick to basic lean concepts and identify the root causes. Looking at causes might not help properly, so there is a need to identify the effects of the solution on the entire system. 4. The final step in the lean implementation process is to find the solutions and test the solutions first: Once solutions are tested then they should be implemented. Training and following up are important in each and every step explained above. One needs to be patient because the implementation process might take a long time.
- 8. The 5 Key Lean Manufacturing Principles 1. Specify the Value of Work. What is the value of your work as perceived by your customer? Identify the value that your customer is paying for or the value that your customer participates in your business. This value may be your unique varieties or products, the practices you use to make them, or the quality of your products or services.
- 9. 2. Map the Steps Value Chain. Map out all the steps in your work as you create that value for your customer. This may start at taking inventory before ordering ingredients, purchasing, receiving, mixing/making a product, packing, taking orders, delivering etc. Start by writing or mapping out the process step-by-step.
- 10. 3. Make the Process Flow Smoothly. Look at all the steps in your work process and eliminate waste and friction points. If there are steps that don’t create the value as perceived by your customer, take them out of the process for that product. 4. Establish Customer Pull. Find ways to create customer „pull‟ for your products instead of having to „push‟ sales based on your production output. Drive demand instead of needing to find homes for product.
- 11. 5. Pursue Perfection Create a culture of continuous improvement, continue to eliminate wastes, document and standardize processes. Make quality and improved processes an ongoing commitment.
- 12. Types of Waste There are seven/Eight types of waste describe as follow:- 1. Overproduction It is unnecessary to produce more than the customer demands, or producing it too early before it is needed. Did you plant too much? Did you hire more people than you need for your sales forecast? Are you throwing out excess product after market or wholesale orders? Are you having lots of meetings without action?
- 13. 2. Defects In addition to physical defects which directly add to the costs of goods sold, this may include errors in paperwork and late delivery. Production according to incorrect specifications, use of too much raw materials or generation of unnecessary scrap. When defect occurs, rework may be required; otherwise the product will be scrapped.
- 14. Generation of defects will not only waste material and labor resources. But it will also create material shortages, hinder meeting schedules, create idle time at subsequent workstations and extend the manufacturing lead time. Do you have to spend a lot of time checking over other people‟s work to make sure it meets your quality needs? Are you reworking or fixing problems with orders?
- 15. 3. Excess Inventory It means having unnecessarily high levels of raw materials, works-in-process and finished products. Are you carrying more supplies than you need? Did you put up more product than you need? Extra inventory leads to higher inventory financing costs, higher storage costs and higher defect rates.
- 16. 4. Transportation. Waste in transportation includes movement of people, tools, inventory, equipment, or products further than necessary. Excessive movement of materials can lead to product damage and defects. Additionally, excessive movement of people and equipment can lead to unnecessary work, greater wear and tear, and exhaustion.
- 17. 5. Waiting It is idle time for workers or machines due to bottlenecks or inefficient production flow on the factory floor. It includes small delays between processing of units. When time is being used ineffectively, then the waste of waiting occurs. This waste occurs whenever goods are not moving or being worked on.
- 18. Are workers waiting on direction between tasks? Is there a bottleneck in your packing process? Is decision-making a holdup in your operation?
- 19. 6. Motion It includes any unnecessary physical motions or walking by workers which divert them from actual processing work. This might include walking around the factory floor to look for a tool, or even unnecessary or difficult physical movements, due to poorly designed ergonomics, which slow down the workers. It involves poor ergonomics of production, where operators have to stretch, bend and pick up when such actions could be avoided.
- 20. 7. Over processing/Incorrect Processing It is unintentionally doing more processing work than the customer requires in terms of product quality or features such as polishing or applying finishing in some areas of product that will not be seen by the customer. Did products get bunched when you need them loose? Is someone trimming every root hair off every beet? Are you wasting time and effort by doing too much?
- 21. 8. Unused Skills Or People Potential A Even though it was not part of the Toyota Production System (TPS), many people are well aware of the 8th waste the waste of human potential. Are your people in positions they’re trained for? Are there ideas for improvement from your team? Are there skills your team doesn’t have that could boost the value of your work?
- 22. Various Lean Tools 1. 5S 2. VSM 3. JIT 4. Poka-yoke 5. SMED 6. Kanban 7. Kaizen 8. Total Productive Maintenance (TPM) 9. One-Piece Flow 10. Work Flow Diagrammatic. All of the above methods focus on identifying and reducing the waste that occurs in a process.
- 23. 1. 5S 5S is a systematic technique used by organizations comes from five Japanese words; Seiri (sort), Seiton (set in order),Seiso (shine), Seiketsu (standardize), and Shitsuke (sustain). This system helps to organize a workplace for efficiency and decrease wasting and optimize quality and productivity via monitoring an organized environment
- 24. 1. Sort: Consists on the removal of everything deemed unnecessary. The workplace should only have what is needed to perform the activities. 2. Set in order: there must be a place for everything and everything should be in its place. Quick and visual identification of tools and areas saves time and facilitates processes. 3. Shine: cleaning the workspace is essential. It reduces the risk of accidents and aids on the inspection of products.
- 25. 4. Standardize: In order to optimize the first three s. standards must be created and followed. 5. Sustain: the last step consists on developing a method to ensure the 5S technique is followed. It requires discipline and focus. Usually, audits are performed to assure the sustainability of the methodology. 5S bring several benefits to a company, being the most relevant one the decrease of waste of time and space.
- 26. Just in time (JIT) It was developed at BRITISH MOTOR CORPORATION (Australia) in SYDNEY in 1950s. it was adopted in JAPAN, between 1960- 1970s particularly at TOYOTA. It is also known as JIT production OR Toyota Production System (TPS). Just in time is a heart of the lean manufacturing. It‟s associated with lean techniques. Just in time production gives right part at the right place at right time. IT is a methodology which aims primarily on reducing flow time within the production system & response time for suppliers & to the costumers.
- 27. Total productive maintenance (TPM) Total productive maintenance is the techniques for reducing the machine down time and eliminates the defect and scrap. TPM is a fundamental pillar of lean. It is introducing awareness of self-maintenance and also introducing the preventive maintenance of machine. It is a system which maintains & improves the integrity of production & quality system through machines, processes, workers, equipment’s which adds business value to the organization. Its aim is to keep all the equipment’s in top working conditions which avoids delays & breakdowns in the manufacturing processes.
- 28. Value Stream Mapping Value Stream Mapping (VSM) is a method developed by Rother and Shook , which permits an overview of the material flow from the raw material acquisition to the final product expedition. Abdulmalek & Rajgopal define VSM as a map to identify waste, improvement opportunities and which lean tools to use.
- 29. In order to apply the VSM methodology, four steps should be followed: Step-1: Selection of the product or family of products to use as improvement. Step-2. Drawing of representation of current state. Step-3. Drawing of the future state, without the inefficiencies previously pinpointed. This is referred as value stream design (VSD).
- 30. Step-4: Elaboration of a work plan to achieve the future state. The use of VSM helps on the identification of waste sources, provides a common language for its analysis and facilitates the understanding of the connections of the material flow. It is also an effective way of registering lead times, setup times and other indicators, in a way which enables the responsible to clearly visualize the system’s performance.
- 32. Kanbans Developed by Ohno on Toyota production lines, kanbans emerged as a solution to the tendency of factories to overproduce. He looked for a way of reducing this waste by finding a means of delivering only what is necessary when necessary. Kanban can be translated from the Japanese as card or signal, and is a visual input used in pull systems. kanban as a lean approach developed in the automotive industry to “pull” materials from the production line in a “just in time” mindset .
- 33. The concept of this method consists on promoting the restock of materials only when required, by receiving and sending signals, usually in the form of cards. This process can be either internal or external to the company In order to assist this practice, supermarkets and milk- runs are utilized. The latter is a transport vehicle which provisions the assembly lines with the components they necessitate from the supermarket.