Periodic Inspection Optimization for a Two-Component System with Dependent Failures

In this research, a novel model is presented to optimize the periodic inspection for a complicated two-component system with dependent failures. In this model, the failures of the first and the second component are soft and hard, respectively. A soft failure of the first component does not have any impact on the second component, but a hard failure of the second component shocks the first component and increases its failure rate. A soft failure cannot be recognized before preventive maintenance. This component is inspected in specific periods and if it has a problem, it is repaired to become similar to a new one. Since a soft failure in the first component will increase the operational costs, in this study, in addition to the periodic inspections, the first component inspection is also carried out during the hard failure of the second component. A novel model is developed here to find the optimum inspection periods in order to minimize the costs of inspection, repair and penalty for delay in identifying the soft failures. A numerical experiment is used and the sensitivity analysis is performed to show the performance and efficiency of the developed model.