Determining the Optimal Maintenance Interval for Autoclave Machines Using Reliability Analysis at PT XYZ

Abstract

The autoclave machine in the Medical Device Department of PT XYZ is the most critical sterilization equipment, with a total of 45 failure incidents during the period from January 2023 to December 2025, which have the potential to cause downtime and production delays. This study aims to determine the optimal preventive maintenance intervals based on reliability for five subsystems of the autoclave machine: the chamber, heat tank, valve and gas inlet, pump motor, and electrical system. The analysis was conducted using the Laplace test to identify failure trends, the Anderson-Darling test to select the best distribution, and parameter estimation via Maximum Likelihood Estimation (MLE). The heat tank subsystem, which showed an increasing failure trend, was modeled using a Non-Homogeneous Poisson Process (NHPP) based on a Power Law Process (PLP), while the other components were modeled using appropriate statistical distributions. The results showed the highest MTBF value for the electrical components at 652,320 minutes and the lowest for the heat tank at 114,258 minutes. The reliability values of each component at t = MTBF range from 0.2873 to 0.5. The optimal preventive maintenance intervals to achieve a 90% reliability target are 74 days (chamber), 8 days (heat tank), 14 days (valve & inlet gas), 30 days (pump motor), and 443 days (electrical).