Just in Time

JUST IN TIME

This paper will introduce and explain the just-in-time concept, a manufacturing production system that was invented by Toyota. It will explain the changes that need to be made to make this idea work, the process and what needs to be done and how Toyota implemented it.

INTRODUCTION

Just in time is a concept invented by Kiichiro Toyoda but it was Taiichi Ohno (“Ohno”) a production engineer at Toyota, who mastered the idea. Just-in-time means to supply to each process what is needed when it is needed and in the quantity needed (Japan Management Association, 1986). Ohno watched the way American supermarkets worked where customers select the types of food they want, place them in their cart and then pays for them. He thought that the idea of the customer only taking the items needed in the amount needed could work with production. Ohno believed that the total cost of an item is more than what most manufacturer include, such as electricity, labor, and equipment. These are not the true cost.

When a worker produces extra work for tomorrow and the next day it creates additional expense. This excess material takes up space in the plant, which means it has to be shipped, then stored, counted, extra personnel are needed to count the items and there is additional inventory. All these are additional unnecessary cost and waste created by the worker making additional material.

Toyota believes that by changing manufacturing methods you would eliminate personnel cost and reduce material cost by only producing what is necessary. This can be done by changing the way things flow and by changing the way the plant is arranged.

ELIMINATE WASTE

One of the concepts that Toyota created was eliminating all waste. This concepts is to eliminate waste in every aspect of the manufacturing, which involves overproducing, time on hand, transportation, the process, unnecessary stock, and producing defective items. Their idea of eliminating waste starts with...