Modelling inspection and replacement quality for a protection system

Alberti, A; Cavalcante, CAV; Scarf, PA; Silva, ALO

Abstract

An inspection and replacement policy for a protection system is described by a mathematical model that incorporates multiple aspects of maintenance quality. A three-state component failure model is assumed, with a defective state preceding failure. The quality of maintenance intervention is modelled by supposing that inspections may misclassify defects (false positives and false negatives) and further that an inspection may induce a defect. The quality of replacement is modelled by supposing that a component arises from a heterogeneous population, composed of weak and strong items and with the mixing parameter determining quality. Isolation valves used in water distribution systems motivate the model development, and a case study is considered in this context. We evaluate the impact of these aspects of the quality of maintenance upon cost and production losses. Defect induction is found to be a key determinant of the cost-optimal policy. The proposed model allows us to verify conditions that justify investment in higher quality maintenance, and thus to provide guidance for prioritization of this investment.

Citation

Alberti, A., Cavalcante, C., Scarf, P., & Silva, A. (2018). Modelling inspection and replacement quality for a protection system. Reliability Engineering and System Safety, 176, 145-153. https://doi.org/10.1016/j.ress.2018.04.002

• Journal Article Type: Article
• Acceptance Date: Apr 6, 2018
• Online Publication Date: Apr 7, 2018
• Publication Date: Aug 1, 2018
• Deposit Date: Apr 9, 2018
• Publicly Available Date: Apr 7, 2020
• Journal: Reliability Engineering & System Safety
• Print ISSN: 0951-8320
• Publisher: Elsevier
• Volume: 176
• Pages: 145-153
• DOI: https://doi.org/10.1016/j.ress.2018.04.002
• Publisher URL: http://dx.doi.org/10.1016/j.ress.2018.04.002
• Related Public URLs: https://www.journals.elsevier.com/reliability-engineering-and-system-safety