Asian Isuzu Casting Center merupakan perusahaan yang bergerak dibidang manufaktur casting parts fo engine. Dengan produk utama Cylinder Block EJ59. Pada bulan Januari-2022 s/d Maret-2023 masih ditemukan produk yang tidak sesuai dengan spesifikasi atau cacat. Jumlah kecacatan setiap bulannya dengan rata-rata keseluruhan sebesar 4%, bila dijumlahkan produksi Cylinder Block EJ59 sebanyak 200.923 per-unit dan terdapat produk defect sebanyak 17.911. Tujuan dari penelitian ini adalah untuk mengurangi cacat produk pada produksi Cylinder Block EJ59. Berdasarkan hasil analisis yang telah dilakukan pada proses produksi Cylinder Block EJ59 dibagian moulding terdapat empat jenis defect yaitu defect sunakui, defect yakitsuki, defect yumore, dan defect norokui. Dari hasil peta kendali P menyatakan bahwa keempat jenis produk defect yang diperoleh tidak ada yang melewati batas control UCL maupun batas control LCL. Maka dari itu kerusakan pada proses produksi Cylinder Block EJ59 masih berada di dalam batas-batas pengendalian. Dari hasil Fmea didapatkan nilai RPN (Risk Priority Number) dari keempat jenis defect antara lain 350,270,240 dan 150. Faktor-faktor yang menyebabkan terjadinya kerusakan pada proses produksi Cylinder Block EJ59 dari hasil diagram fishbone adalah faktor manusia, metode, mesin dan bahan baku. Setelah diketahui penyebab defect, maka dilakukan usulan perbaikan menggunakan 5W+1H dan pelaksanaan 5S guna mengurangi jumlah defect pada proses produksi Cylinder Block EJ59 yaitu dengan membuat jadwal perawatan dan pembersihan mesin produksi, pengecekan bahan baku diawal sebelum masuk kegudang penyimpanan bahan baku, mengawasi operator terkait penuangan cairan pouring kedalam cetakan mould dan diberlakukan  SOP  agar  operator  memiliki kedisiplinan dan loyalitas pada saat bekerja

ABSTRACT
 
Kusuma Mulia Plasindo Infitex is a company engaged in the manufacturing sector that produces products, one of which is polypropylene plastic. The problems that occurred at PT. Kusuma Mulia Plasindo Infitex is the occurrence of products that do not comply with standards or defective products. Types of defective products include side breaks and folds in the middle with a total of 277 defective products. The purpose of this study was to determine the factors that cause defects in PT. Polypropylene plastic products. Kusuma Mulia Plasindo Infitex . This study uses the seven tools method. The seven tools method uses 7 quality control tools, namely Check Sheets, Control Charts, Cause and Effect Diagrams, Pareto Diagrams, Histograms, Scatter Diagrams and Flowcharts. From the results of research using the seven tools method, it can be seen that the causes of defects in Polypropylene plastic products are caused by 4 aspects, namely machine factors caused by age and machine maintenance, materials that are not according to standards, human factors caused by lack of training and factors of workers' methods that are not according to SOP/standard operating procedures.
 
Keywords: Quality Control, Polypropylene plastic products, Seven Tool.

PT.X is a manufacturing company whose one product is Gallon Paint bucket 5kg. The problems faced by this company are factors that cause production defects, it is necessary to improve the quality of 5kg paint gallons. the flow of stages in the research using the New Seven Tools method with the stages, namely affinity diagrams, Affinity Diagrams, Relationship Diagrams, Tree diagrams, Matrix Diagrams, Data Analysis Matrix, Arrow Diagrams, Process Decision Program Charts. With the results of this study, it is known that the factors of the occurrence of production defects are the human factor The condition of the operator is sick, the operator is in a hurry, the lack of understanding of the production machine. Material factors Inappropriate mixing of raw materials. Machine Factors Short Machine Maintenance Time, Number of Machines That Are Not Operating, Lack of Spare Parts To Do Maintenance. Factors SOP method of Quality Standards that are not written in the production section. Environmental factors Hot Working Environment Temperature, Long Distance Between Production, Noisy Work Environment. The suggestion given to reduce this production defect is to give sick leave for 3 days. Adding operators to the Inject Molding machine at least 2. Providing training on the operation of the machine to each operator. Preparation of appropriate raw material mixture formulas. Placing unused machines in 1 warehouse room. Making regular and strict maintenance schedule for machine maintenance. Stocking spare parts in the Workshop room Providing understanding of product defect SOPs. Providing a fan in the room and increasing air ventilation. Updated the production line layout. Place the machine in a soundproof room and wear earplugs.