Anais do Simpósio Brasileiro de Pesquisa Operacional
Proceedings of LVI Brazilian Symposium on Operations Research

This work succinctly presents some contributions of a PhD thesis, highlighting the importance of protection systems in maintenance management. Unlike critical systems, protection systems fail silently, leading to potential disasters during unmet demands. The research developed models that consider competitive failure modes, incorporating both internal degradation and external shocks, inspired by real-world problems. Two new hybrid (inspections & preventive replacement) maintenance policy models are proposed. The first model addresses single-component systems with failures following a shot-noise process, where activation accelerates deterioration. The second model deals with heterogeneous populations (weak and strong components), using the delay-time concept, where the shock rate follows a non-homogeneous Poisson process. Numerical studies showed significant cost reduction potential compared to classical policies. Results indicate when inspections should be prioritized over age-preventive replacement, and vice versa, and when they should act together. In addition, user-friendly web applications were developed, allowing readers to explore the models.