Usulan Perbaikan pada Pemborosan Penggunaan Dosis PAC dan Mengeliminasi Waste pada Proses Produksi dengan Pendekatan Lean Six Sigma di PT. XYZ

Abstract

PT. XYZ is a company focused on providing and distributing drinking water, primarily in the city of Medan and its surrounding areas. To maintain water quality, the company adds doses of PAC (Poly Aluminium Chloride) to reduce water turbidity in the water treatment process. The company faces the issue of waste in the use of PAC doses, including waste due to overproduction, defects, inventory, and motion, amounting to 35.9%. Additionally, in the water production process, there is waste in the form of waiting time activities. The objective of this research is to identify and eliminate non-value-added activities and determine the ranking of wastes that are the main causes of waste using the Lean Six Sigma approach, Process Activity Mapping, and Waste Assessment Model, and to provide improvement suggestions using the 5W+1H method. Based on observations and measurements, there are 12 activities, with 1 non-value-added activity amounting to 19.69 minutes, a manufacturing lead time of 327.98 minutes, a process cycle efficiency rate of 52.18%, and a process velocity of 0.036 processes/hour. After eliminating the 1 non-value-added activity, the improvement results showed a manufacturing lead time of 308.29 minutes, a process cycle efficiency rate of 55.51%, and a process velocity of 0.033 processes/hour. According to the Waste Assessment Model calculations, the main waste rankings are overproduction at 37.06% and defects at 25.22%. To reduce PAC dosage waste, the proposed improvements include enhancing supervision and control of water production to ensure that production does not exceed actual needs and increasing understanding and control of PAC dosage to reduce errors