Machine damage can cause downtime which will disrupt production activities and cause delays in product supply to the market. In addition, downtime will also increase production costs so that products become less competitive. To prevent machine damage, it is necessary to perform effective preventive maintenance activities. This study aims to determine the cause of machine damage at PT XYZ Farma and determine actions for improvement. The research methods used are quantitative descriptive and qualitative. Data on Preventive Maintenance, Corrective, and Breakdown Maintenance were collected from January 2020 to May 2023. Root Cause Analysis (RCA) using fishbone diagrams is used to determine the cause of machine damage. For the sample of the study, the Tablet Blistering Machine, one of the critical machines, was selected. Based on the results of RCA, it is known that 3 main problems cause machine damage, which are incomplete Preventive Maintenance procedures, human error of technician or operator, and age of spare parts. Furthermore, corrective actions are formulated through Focus Group Discussion which aims to address the root of the problem so that subsequently the effectiveness of Preventive Maintenance can be increased, and downtime reduced.