Investigation of reliability, maintainability and availability of a paper machine in an integrated pulp and paper mill

Continuous production of an integrated pulp and paper mill depends on the availability of paper machines. Reliability and maintainability are essential for accomplishing the availability of paper machines. This study investigates the reliability, availability and maintainability (RAM) characteristics of a 120 tonnes per day paper machine from a paper mill in southern region of India. The paper machine is divided into five subsystems for failure analysis. The data was analyzed for trend and serial correlation tests for validating the inference of independent and identical distribution of failure and repair information before each sub system is best fitted to the theoretical probability distributions. Reliability and maintainability of the paper machine has been evaluated at various times which are useful for establishing the preventive maintenance schedules for improving availability of the paper machine. Wire part is found to be more critical subsystem from all points of view and require improvement by 4% and 1.5% in maintainability and availability point of view. The results of the analysis are presented to maintenance department for their active consideration. Keywords: Paper machine, reliability, maintainability, availability, mean time between failures (MTBF), mean time to repair(MTTR), independent and identically distributed(IID)