Effect of Risk Priority Number Values for Multiple Effects in Maintenance Optimization

Abstract

In this paper, authors describe an optimization framework for finding optimal maintenance policies in continuous process operations and analyze and quantify the reaction of different variables on optimal maintenance schedules. A necessary idea behind maintenance optimization is that of life-cycle costing, where the total cost of design, building, maintenance, is considered over the entire life span of the system or structure in question. The system’s effectiveness measure is introduced which depends on expected process profitability and process and reliability/maintenance characteristics. A mixed integer nonlinear optimization model is proposed which aims at identifying the number of maintenance (preventive or corrective) actions required over a given time so that the system effectiveness is maximized. Here, authors review mathematical decision models to optimize time-based maintenance (e.g., in terms of age- and block-replacement intervals) and condition-based maintenance (e.g., in terms of inspection intervals)..

Keywords: Risk priority number, different rating scale, maintenance optimization