Relations of Imperfect Repairs to Critical Infrastructure Maintenance Costs

Abstract

This article presents an analysis of maintenance costs and maintenance policy of critical infrastructure systems, considering the case of imperfect repair. The maintenance costs of the systems, considering a multistate approach and imperfect repairs, are analyzed with reference to the renewal stream and renewal process theory. Availability characteristics of repairable critical infrastructure systems with non-negligible renovation time, necessary for the cost analysis, are determined based on classical renewal theory. We assume that the system is renewed after exceeding its critical reliability state. The multistate approach proposed to availability analysis, including imperfect repairs, allows considering various configurations of the system’s renewals. The procedure for determining the total cost of maintenance up to certain point in time is proposed. Furthermore, the procedure comparing the costs of repair and operation of the system until a certain moment for different configurations of the number of repairs to various reliability states is put forward and its exemplary application is presented. Conducting perfect renewals of infrastructure to the state of entire availability seems to be the most profitable in the case study analyzed in the article. The exception is when imperfect repairs are much cheaper than perfect repairs (they are up to half of the perfect repair cost), or when costs of an infrastructure’s renewals are considered in the short period of its exploitation (up to one year). The summary provides a conclusion on maintenance policy based on the proposed procedure analysis and a comparison of maintenance costs for various configurations of perfect and imperfect repairs.

Contextualizing resilience to critical infrastructure maintenance supply networks

“…In CI networks, maintenance facilitates resilience and as such reduces social and economic costs that might occur due to disruptions (Cantelmi et al , 2021). The findings of this study underline that it is particularly important for CI supply networks to approach maintenance management strategically and systematically (Simões et al , 2011) as it is a key determinant of the resilience of the network (Blokus and Dziula, 2021). Contextualizing resilience to the CI setting, we were able to generate new insights on maintenance resource configurations for both structural and social elements.…”

“…Accordingly, Dominguez et al (2009) propose that organizations managing CI should focus on improving organizational processes. This suggests that CI resilience could be closely linked to the management of the maintenance supply network (Blokus and Dziula, 2021): ongoing maintenance helps to reduce business risks by hazard elimination, ensures the ability of continuous performance and decreases the length of disruptions (Marais and Saleh, 2009). However, supply network maintenance in CI provision has received minimal attention, despite the risk of a disruption being greater [than (say) from an occasional disaster (Hemme, 2015)] if maintenance is not properly managed.…”

“…In summary, the maintenance resource choices outlined in Table 1 can help an organization to become more resilient by choosing and positioning strategic surplus resources (Tukamuhabwa et al , 2015). At the same time, redundant resources add to operating costs of CI providers and organizations also need to keep their service affordable (Blokus and Dziula, 2021). Furthermore, the maintenance supply network in itself represents a large proportion of cost for CI as it relates to thousands of kilometers of (underground) network with an operational history (geographically spread and network location) that is tightly coupled and interactively complex (network properties).…”

“…Beyond the specific CI network attributes that might influence building supply network resilience, there is pressure on CI organizations to keep costs low (Blokus and Dziula, 2021). Hence, organizations need to balance investment in resilience (e.g.…”

“…redundancy and IT systems for increased agility; Christopher and Peck, 2004) with the costs of service provision. Resource decisions that affect both resilience and costs in CI supply networks are usually associated with maintenance activities (Hemme, 2015) as proper maintenance guarantees the functioning of CIs (Blokus and Dziula, 2021) and determines, for example, the length of downtime. Accordingly, we consider the configuration of physical, manpower and information resources in a maintenance supply network (Hastings, 2015; Tsang, 2002) and their impact on costs as a key part of contextualizing resilience knowledge to the CI setting.…”