JIT AND LEAN PRODUCTION SYSTEM BY AMAR P. NARKHEDE

INTRODUCTION Just in Time production logic evolved in Japan at Toyota later extended to other companies in Japan and other countries. Lean production is an integrated set of activities designed to achieve high volume production using minimal inventories of raw materials, work in progress and finished goods. Parts arrive t the next work station Just in Time is also based on the logic that nothing will be produced until it is needed. Need is created by actual demand for the product. JIT is the philosophy of operations management that seeks to eliminate waste in all aspects of a firm’s production activities Human relations, vendor relations, technology and management of materials and inventories. Little inventories focuses more narrowly on scheduling good inventories and providing services resources where and when needed

THE TOYOTA PRODUCTION SYSTEM The Toyota production system was developed to improve quality and productivity and is directed by two philosophies that are central to the Japanese culture Elimination of waste and Respect for People ELIMINATION OF WASTE: Waste as defined by Toyota’s President Fujio Cho as “Anything other than the minimum amount of equipment, materials, parts and workers (working time) which are absolutely essential to production”

SEVEN PROMINENT TYPES OF WASTE Waste from overproduction Waste of waiting time Transportation waste Waste of processing itself Waste of stocks Waste of motion Waste of making defective parts This definition of JIT leaves no room for surplus or safety stock. No safety stock are allowed because if you cannot use it now, you do not need to make it now that would be waste. Hidden inventory in storage areas, transit system, carousels and conveyors is key target for inventory reduction

SEVEN ELEMENTS THAT ADDRESS ELIMINATION OF WASTE ARE Focused factory network Group technology Quality at the source JIT production Uniform plant loading Kanban production control system Minimized set up time

TECHNIQUES OF JIT Set up time reduction Autonomous or modular cells JIT layout The pull system Buffer stock removal Continuous improvement Total productive maintenance Quality at source Just in time purchasing Employee improvement

THE KANBAN SYSTEM (THE PULL SYSTEM) Kanban signals are required when a.Assembly work, sub assembly work and manufacture of parts is carried out at different locations and it is impractical to move product one at time over long distance b.Set up time on the feeding operations is higher than receiving operation c.On or more machines are common to various work cells and need to be linked to the cells with Kanban signals. Linking the common machines an integral part of each work cell on account of frequent signals from the cell as to what to produce and when d.There are bottlenecks or quality or capacity problems which do not allow smooth flow

WHAT IS KANBAN SYSTEM The working of Kanban system can be compared to supermarket shelf which is continuously monitored and refilled as customers help themselves. At the supermarket, the customers pick up quantities of goods they need. At the periodic intervals the employee checks up to see what customers have taken and what he puts back what has been taken. Quantities picked up by the customers are the quantities put on the shelves by the employee. The Kanban system performs the same activity Kanban is the Japanese word for a Card

KANBAN SIGNALS MAY BE ONE OF THE FOLLOWING A card on which is written the part number, size of the container, number of pieces to beheld by the container, and number of this cards in the system Metal plates affixed to the container that are useful in an oily environment and display the same kin of information as on the card Containers themselves Computer to computer Kanban system Two types of Kanban system exist: single card Kanban system and double card Kanban system. In a double card system, two cards are used: a Withdrawal Kanban(C-Kanban) and production Kanban(P- Kanban). A withdrawal Kanban specifies the kind and the quantity which the subsequent process should withdraw from the preceding process while a production Kanban specifies the kind and the quantity of the product which preceding process must produce

The contents of Kanban are: a.Part name b.Part number c.Kanban number d.Work station(from) e.Work station(to) f.Quantity g.Container number(or Box)