Waste Reduction IN Onion Packing Process BY USING TOYOTA PRODUCTION SYSTEM (TPS): A STUDY AT THAWORNKARNKASET PACKAGEING PLANT

Abstract

The onion is one of the Thai domestic agricultural products affected by foreign products in terms of both domesticconsumption and exporting markets. Purchase of domestic orders is decreasing as well as the quantities being exported. So, this research aims to find out how to improve the process involved with onion product especially by reducing any waste in the packing process by using the Toyota Production System (TPS). This action research studiesthe Thawornkarnkaset Packing Plant,a major onion plant located in Mae Wang District in Chiang Mai - the main area forcultivationonions in Thailand- starts from the packing process in the factory through participant observation.This research identified the whole process as consisting ofpurchasing onions and delivery from vendors, quality screening, size selection according to each customer’s order, packing and package weighting, until finally the package is sealedand ready to delivery. The research also studied the relevant problems and wastes in the entire processes by analyzing and brainstorming throughdiscussion with the relevant production persons and identified the four major causes of the problems; (1) working procedure, (2) workers, (3) equipment, and (4) onions. These cause fourareas of wastes; (1) unnecessary transportation, (2) over-processing, (3) waiting, and (4) defects. This research substantially determines the detailed process of improvement approaches in plant lay out, activities and working methods according to TPS’s continuous improvement techniques, or Kaizen, from observing and improving the found wastes. These techniques focus on the production process and products that flow more smoothly from certain daily production plans, rearranging the plant lay out in order to reduce any excessive distance or time in conveyance and to reduce over-processing activities, reducing any repeated activity in the process by reducing the number of production cycles and their set up times for each onion size, levelling out the workload, or Heijunka, providing a pull system and parallel production lines, etc. The above improvementsresult in better production lay-out and can be control through visual media conveniently. Moreover, there are additional measurements providing safety equipment for the health care of each worker during working operations. This research also determined the process controls such as the form of waste analysis and performance evaluation for process implementation.