Introduction to Lean Manufacturing Lean Manufacturing Definition Lean

Introduction to Lean Manufacturing

Lean Manufacturing Definition Lean has been defined in many different ways. “A systematic approach to identifying and eliminating waste(non-value-added activities) through continuous improvement by flowing the product at the pull of the customer in pursuit of perfection. ” By The MEP Lean Network Intro-To-Lean

History Timeline for Lean Manufacturing Intro-To-Lean

Reducing Waste: Push versus Pull System Raw Material Supplier Final Assembly Customer FGI PUSH Raw Material Supplier Final Assembly Customer FGI PULL Information Flow Material Flow

Production Planning System (Push System) Intro-To-Lean

Lean manufacturing is a philosophy In 1990 James Womack, Daniel T. Jones, and Daniel Roos wrote a book called “The That Changed the World: Machine The Story of Lean Production-- Toyota's Secret Weapon in the Global Car Wars That Is Now Revolutionizing World Industry” In this book, Womack introduced the Toyota Production System to American. What was new was a phrase– "Lean Manufacturing. " Intro-To-Lean

Muda (Waste) Taiichi Ohno (1912 -1990), the Toyota executive who was the most ferocious foe of waste human history has produced, identified the first seven types of muda in manufacturing system: • Storage • Transportation • Waiting • Motion • Process • Defects • Over-production Muda is everywhere. Intro-To-Lean

Elimination of Waste 1. 5 S 2. Group technology 3. Quality at the source 4. JIT production 5. Kanban production control system 6. Minimized setup times 7. Uniform plant loading 8. Focused factory networks 8

The Five S’s n n n Sorting – separating the needed from the not-needed Simplifying – a place for everything and everything in its place, clean and ready to use Systematic Cleaning or Sweeping – cleaning for inspection Standardizing – developing common methods for consistency Sustaining – holding the gains and improving

Minimizing Waste: Group Technology Using Departmental Specialization (Job Shop) for plant layout can cause a lot of unnecessary material movement Note how the flow lines are going back and forth Saw Saw Grinder Heat Treat Lathe Press

Minimizing Waste: Group Technology Revising by using Group Technology Cells can reduce movement and improve product flow Grinder Saw 1 2 Lathe Press Heat Treat Grinder Saw Lathe A B

Minimizing Waste: JIT § § § Only produce what’s needed The opposite of “Just In Case” philosophy Ideal lot size is one Minimize transit time Frequent small deliveries ? ? ? Pro’s Con’s • Minimal inventory • Requires discipline • Less space • Requires good problem solving • More visual • Suppliers or warehouses must be close • Easier to spot quality issues • Requires high quality

Minimizing Waste: JIT Inventory Hides Problems Machine downtime Scrap Work in process queues (banks) Paperwork backlog Vendor delinquencies Change orders Engineering design redundancies Inspection backlogs 13 Design backlogs Decision backlogs

Minimizing Waste – Quality at the Source § “Do it right the first time” § Call for help Andon § Immediately stop the process and correct it vs. passing it on to inspection or repair

Jidoka

Minimizing Waste – Kanban Signaling device to control flow of material • Cards • Empty containers • Lights • Colored golf balls • Etc

Minimizing Waste – Setup Times § Long setup times drive: § Long production runs § Large lots § Long lead times § JIT requires small lots and minimum kanbans § Setup reduction § Focused efforts § Problem solving § Flexible equipment

Minimizing Waste – Plant Loading. Heijunka Suppose we operate a production plant that produces a single product. The schedule of production for this product could be accomplished using either of the two plant loading schedules below. Not uniform Uniform Jan. Units Feb. Units Mar. Units Total 1, 200 4, 300 9, 000 Jan. Units 3, 500 or Feb. Units Mar. Units Total 3, 000 9, 000 How does the uniform loading help save labor costs? 18

Minimizing Waste – Focused Factory Networks Coordination System Integration These are small specialized plants that limit the range of products produced (sometimes only one type of product for an entire facility)

TPS – Respect for People § Level payrolls § Cooperative employee unions § Subcontractor networks Keiretsu § Bottom-up management style § Quality circles (Small Group Problem Solving)

TPS – 4 Rules 1. All work shall be highly specified as to content, sequence, timing, and outcome 2. Every customer-supplier connection must be direct, and there must be an unambiguous yes-or-no way to send requests and receive responses 3. The pathway for every product and service must be simple and direct 4. Any improvement must be made in accordance with the scientific method, under the guidance of a teacher, at the lowest possible level in the organization

Lean Implementation Total Quality Management Product Design Flow Process Continual Inventory Reduction Empowered Workforce Problem Solving Performance Measurement Involved Suppliers Stable Schedule Kanban Pull

Intro-To-Lean

Which to Choose — MRP (ERP), or Kanban? Where MRP (ERP) works best: ü MRP is by its very nature a forward-looking system. ü MRP can be very effective in an environment with a great deal of variability. ü MRP is recognized an engine to drive an integrated enterprise-wide information system. Purchasing and logistics activities were similarly being integrated with fundamental internal materials management principles into an enterprise-wide approach. Intro-To-Lean

MRP or Lean Manufacturing? Where MRP is not as effective. Ø MRP is a predictive system. It does not reflect to customer’s demand (easy to get overproduction). A company takes MRP suggestions and acts on them without too much review is very risky. ØMRP won’t fully support the cost-cutting. ØMRP needs lots of data for production management. ØMRP generates high overhead. ØMRP builds high work-in-process. ØMRP’s lead times are fixed. ØMRP creates potential quality hazard. Intro-To-Lean

Which to Choose — MRP (ERP), or Kanban? Where Kanban works best. Kanban is a very reactive system. Very little is planned ahead. Instead, Kanban causes replacement of material used in a totally reactive mode. Kanban works best in a highly stable and predictable environment. Where it is not as effective. Kanban can quickly fail in a highly volatile environment because of the reactive nature of the system. Volatility in customer demand, processing problems, and extensive changes in product designs make it very difficult for a Kanban system to work effectively. Intro-To-Lean

Which to Choose — MRP (ERP), or Kanban? Kanban and MRP Combination The combination of these two systems is becoming quite common. An MRP system is used for advanced planning, including long lead-time purchased materials, adding resources, and implementing product design changes. Once the MRP has the materials and resources “lined up, ” however, Kanban is used as an execution system, bringing with the characteristics of rapid response to customer order and reduced inventory levels throughout the process. Hybrid Systems Intro-To-Lean

The Objections to Lean How should you deal with these objections to lean? • “It is very hard to deal with raw material suppliers if we fully depend on customer order. ” • “It takes too much discipline. ” • “It takes too long to implement. ” • “My process is too complex; I have to deal with too many uncontrollable variables, like late supplier shipments, sick people, etc. ” • “My process requires a large batch size. ” • “It doesn’t make sense in my industry. ” • “It’s unclear to me how lean will work with my MRP system. ” Intro-To-Lean

References • • Society of Manufacturing Engineers, Lean Manufacturing 2007, Supplement to Manufacturing Engineering, 2007. Society of Manufacturing Engineers, Lean Manufacturing 2008, Supplement to Manufacturing Engineering, 2008. Garrett Brown and Dara O’Rourke, “Lean Manufacturing Comes to China: A Case Study of its Impact on Workplace Health and Safety, ” International Journal of Occupational and Environmental Health (IJOEH), 13(3), JUL/SEP 2007. Challenges in Applying Lean Manufacturing in China, Mc. Kinsey Quarterly, 2006 Special Edition available at Jackson Library. Friday, October 12, 2007 | Posted by Simone Yu in International Intro-To-Lean