PT KAI is a company that provides mass transportation services, which must carry out maintenance to maintain the performance of its fleet. The company has implemented a preventive maintenance pattern, but it is not optimal and is still reactive. This study discusses the analysis of the application of these patterns on the Electric Rail Train and designing the information system. The research uses quantitative methods by performing calculations using historical damage data, damage intervals, and data on repairs or maintenance carried out in the January-December period 2020 and the business processes that occur during maintenance. From these data, calculations were made to find KRL and critical components, the value of availability, reliability, and downtime of each component. The analysis is carried out using the data from the calculation and then analyzing each critical component from a technical point of view. The result of the discussion is that Preventive Maintenance can increase the availability and reliability of the 8000 Series KRL components, namely carbon brush, brake pad shoe and SIV, but there is also an increase in downtime