Continuous Improvement Of Imperfect Maintenance Actions In Pas And Par Models

In this paper, an unavailability model is proposed to define the test and maintenance policies of systems that are subject to hidden failure and degradation, assuming practices of continuous improvement (CI) under imperfect maintenance actions with Proportional Age Setback (PAS) and Proportional Age Reduction (PAR). For this, two CI equations are analyzed to estimate the progress of maintenance effectiveness over time, and a maximum unavailability constraint is incorporated into the model for evaluation of safety point of view. A numerical application was performed, and the results showed that by adopting CI practices over maintenance actions, the unavailability of the system is reduced in greater proportion over time, besides contributing positively to safety.