JUST IN TIME

JUST IN TIME

ABSTRACT

Just In Time (JIT)

Just-in-time (JIT) is a management philosophy that strives to eliminate sources of manufacturing waste by producing the right part in the right place at the right time. Waste results from any activity that adds cost without adding value , such as moving and storing. JIT (also known as lean production or stockless production) improves profits and return on investment by reducing inventory levels (increasing the inventory turnover rate), reducing variability, improving product quality, reducing production and delivery lead times, and reducing other costs (such as those associated with machine setup and equipment breakdown). In a JIT system, underutilized (excess) capacity is used instead of buffer inventories to hedge against problems that may arise.

JIT applies primarily to repetitive manufacturing processes in which the same products and components are produced over and over again. The general idea is to establish flow processes (even when the facility uses a jobbing or batch process layout) by linking work centers so that there is an even, balanced flow of materials throughout the entire production process, similar to that found in an assembly line. To accomplish this, an attempt is made to reach the goals of driving all queues toward zero and achieving the ideal lot size of one unit.

INTRODUCTION

Just in Time originated in Japan. It was introduced as a technique, philosophy, and/or way of working in manufacturing after the Japanese had viewed the inefficiencies of the Ford Motor Company in the United States. It is generally associated with the Toyota Motor Company, because their Chief Engineer at the time in the 1950’s, Taiichi Ohno, developed the technique. The beginnings of this production system are rooted in the historical situation that Toyota faced. After the Second World War the president of Toyota said "Catch up with America in three years, otherwise the automobile industry of Japan will not survive”. Ohno began to examine the American industry and found that American manufacturers made great use of economic order quantities - the traditional idea that it is best to make a "lot" or "batch" of an item before switching to a new item. They also made use of economic order quantities in terms of ordering and stocking the many parts needed to assemble a car. Ohno decided that waste that happened in America would have to be decreased if he were to develop a technique for Japan, so he proposed decreasing waste by making it were items only move through production when they are demanded, and that they would have to set up a program where inspection for problems would occur and stop the process until they were repaired, thereby reducing waste.

Download full seminar papers At
http://www.enjineer.com/forum