Reliability Evaluation and Risk Based Maintenance in a Process Plant

An effective operation of process plant depends on the maintenance practices followed and its operating reliability. In process plants having increasing demand for its product, the effective operation is very important. This must be met by increasing its production. Prior to an increase in production, reliability evaluation and maintenance planning are unavoidable. Ultimate aim is to increase the performance of the machineries without compromising safety or environmental issues. Maintenance strategies of the plant affect the performance of the machineries and hence affects production. Allocating more maintenance resources for the components having high risk of failure will improve the total availability of the system. Thus it is considered as the first step to improve reliability of components. Calculating availability of the plant will give a good measure of reliability of the components in the system. Assessment of the risk of failure is equally important as reliability evaluation and plays an important role in improving plant availability. This work discusses the importance of evaluating reliability and risk of failure in planning a maintenance schedule and thereby improving availability of the plant. A model for improving plant availability has been proposed. By applying this model, an optimum maintenance schedule for the process plant can be formed. Improvement in availability of plant after employing the optimum schedule was calculated. A case study of a cement plant has been used to demonstrate the methodology. Results indicate that the methodology is successful in identifying the critical equipments and improving the availability of the system.