Hybrid Inspection/Age-Based Policies: Inspector Assignment and Grouping Optimization Models

Abstract

The maintenance function in corporations exhibits strong and complex interrelations with other business functions. While various maintenance policies and mathematical models have been proposed to address operations and maintenance (O&M) problems, the integration of maintenance with other operational decisions remains underexplored, even for critical systems. Recognizing the potential of hybrid maintenance policies (which combine different strategies) and the relevance of modeling component degradation as a three-stage process (Delay-Time Modeling), this work develops three models for both single- and multi-component systems, incorporating population heterogeneity of components. The models emphasize the importance

of joint optimization of maintenance and personnel assignment by incorporating multiple in- spection teams with distinct performance metrics, operating under a hybrid inspection and

age-based policy. Moreover, component interdependencies are addressed from an economic perspective, allowing for cost-sharing of simultaneous actions and thereby reducing setup

costs. To handle this, both stationary and dynamic grouping maintenance models are pro- posed. Numerical studies demonstrate the efficiency and advantages of the proposed models

compared to traditional approaches that ignore such interdependencies and relations under the hybrid strategies. To support practitioners and readers less familiar with the mathematical or maintenance background, web-based applications have been developed, offering user-friendly access to the models and their results.