31-07-2013, 04:06 PM
Lean Manufacturing
Lean Manufacturing.ppt (Size: 7.15 MB / Downloads: 48)
Definition
Lean Manufacturing – A way to eliminate waste and improve efficiency in a manufacturing environment
Lean focuses on flow, the value stream and eliminating muda, the Japanese word for waste
Lean manufacturing is the production of goods using less of everything compared to traditional mass production: less waste, human effort, manufacturing space, investment in tools, inventory, and engineering time to develop a new product
Lean and Just-in-Time
Lean was generated from the Just-in-time (JIT) philosophy of continuous and forced problem solving
Just-in-time is supplying customers with exactly what they want when they want it
With JIT, supplies and components are “pulled” through a system to arrive where they are needed when they are needed
What is Waste?
Waste is anything that happens to a product that does not add value from the customer’s perspective
Products being stored, inspected or delayed, products waiting in queues, and defective products do not add value
Seven Wastes
Overproduction – producing more than the customer orders or producing early. Inventory of any kind is usually waste.
Queues – idle time, storage, and waiting are wastes
Transportation – moving material between plants, between work centers, and handling more than once is waste
Inventory – unnecessary raw material, work-in-process (WIP), finished goods, and excess operating supplies
Motion – movement of equipment or people
Overprocessing – work performed on product that adds no value
Defective product – returns, warranty claims, rework and scrap
Underlying Principles to TPS
Work shall be completely specified as to content, sequence, timing, and outcome
Every customer-supplier connection, both internal and external, must be direct and specify personnel, methods, timing, and quantity of goods or services provided
Product and service flows must be simple and direct – goods and services are directed to a specific person or machine
Any improvement in the system must be made in accordance with the “scientific method” at the lowest possible level in the organization
Kanban
A system that uses replenishment signals to simplify inventory management
Signals (usually cards) hold product details
What to make, when to make it, how much to make, and where to send it
Cards stay attached to a bin that holds the product
When bin is empty, it is returned to the start of the assembly line for replenishment
Full bins are returned to the customer, and the cycle continues