PT WPP merupakan industri manufaktur yang memproduksi pipa stainlees. Karena keadaan daya saing bisnis saat ini, organisasi harus dapat mempertahankan ketergantungan peralatan manufaktur mereka untuk memastikan kelancaran proses produksi.. PT WPP mengaplikasikan metode preventive maintenance pada perawatan mesin produksinya hanya saja dalam penentuan jadwal belum optimal, hanya berlandaskan patokan dari kegagalan-kegagalan yang terjadi sebelumnya. Dalam mesin produksi pipa stainlees, PT WPP memiliki 3 mesin produksi yaitu mesin slitter, mesin milling pipe, dan mesin polishing. Mesin produksi yang memiliki breakdown tertinggi yaitu mesin milling pipe dengan frekuensi breakdown 444. Berdasarkan analisis pareto didapatkan 8 komponen kritis dengan downtime tertinggi yaitu abrasive, gearbox, sander, cutter, as cutter, welding, water pump, dan hower. Simulasi monte carlo dapat menguji jadwal perawatan yang optimal. Hasil dari Simulasi didapatkan interval waktu perawatan preventive untuk komponen abrasive 11 hari, komponen gearbox 15 hari, komponen sander 23 hari, komponen cutter 9 hari, komponen as cutter 170 hari, komponen welding 43 hari, komponen water pump 32 hari, dan komponen hower 25 hari. Dengan mengaplikasikan interval waktu optimum dapat meningkatkan keandalan menjadi 35,33% hingga 65,33%. ABSTRACT PT WPP is a manufacturing industry that produces stainless steel pipes. Due to the current state of business competitiveness, organizations must be able to maintain dependence on their manufacturing equipment to ensure the smooth running of the production process. PT WPP applies the preventive maintenance method to the maintenance of its production machines but the schedule is not optimal, only based on the benchmark of failures that occur previously. In terms of stainless steel pipe production machines, PT WPP has 3 production machines namely slitter machines, pipe milling machines and polishing machines. The production machine that has the highest breakdown is the pipe milling machine with a breakdown frequency of 444. Based on the Pareto analysis, 8 critical components with the highest downtime are obtained, namely abrasives, gearbox, sander, cutter, axle cutter, welding, water pump, and hower. Monte carlo simulation can test the optimal maintenance schedule. The results of the simulation obtained preventive maintenance time intervals for abrasive components 11 days, gearbox components 15 days, sander components 23 days, cutter components 9 days, axle components cutter 170 days, welding components 43 days, water pump components 32 days, and hower components 25 day. Applying the optimum time interval can increase the reliability to 35.33% to 65.33%.