An integrated strategy for fleet maintenance planning

Abstract

Purpose Conventionally, fleet maintenance decisions are made based on the level of repair (LOR) analysis. A general assumption made during LOR analysis is the consideration of the lifetime distribution with constant failure rate (CFR). However, industries do use preventive maintenance (PM) to extend the life of such components, which in turn may affect the LOR decisions such as repair/move/discard. The CFR assumption does not allow the consideration of effect of PM in LOR analysis. The purpose of this paper is to develop a more practical LOR analysis approach, considering the time-dependent failure rate (TDFR) of components and the effect of PM. Design/methodology/approach In the proposed methodology, first, a detailed life cycle model considering the effect of various parameters related to LOR and PM is developed. A simulation-based genetic algorithm approach is then used to obtain an integrated solution for LOR and PM schedule decisions. The model is also evaluated for the various cases of quality of maintenance measured in terms of degree of restoration. Findings The results, from the illustrative example for a multi-indenture and multi-echelon fleet maintenance network, show that the proposed integrated strategy leads to better LCC performance compare to the conventional approach. Additionally, it is identified that the degree of restoration also affects the PM schedule as well as LOR decisions of the fleet system. Therefore, consideration of TDFR is important to truly optimize the LOR decisions. The proposed approach can be applied to fleet of any equipment. Research limitations/implications The approach is illustrated using a hypothetical example of an industrial system. A more complex system structure in terms of number of machines, types of machines (identical vs non-identical), number of echelons, possible repair actions at various echelons, etc. may be present for a particular industrial case. However, the approach presented is generic and can be extended to any system. Moreover, the aim of the paper is to highlight the importance of the considering PM and quality of maintenance in LOR decision making. Originality/value To the best of the authors’ knowledge, this is the first work which considers the effect of PM and quality of maintenance on LOR analysis. Consideration of TDFR and imperfect maintenance while optimizing LOR decisions is a complex problem. Thus, the work is of high significance from the research point of view. Also, most of the real life fleet systems use PM to extend the life of the equipment. Thus, present paper is a more practical approach for LOR analysis of such systems.

Fleet-Level Selective Dispatch and Imperfect Maintenance Strategy Optimization Based on Evolutionary Co-Petition Game Theory

“…Adopting the superscript s2r for indicating the strategy in round r for equipment in the second set of the standby group, the maintenance strategy can be expressed as l s2r j . The strategy space is generated as SS s2r j = l s2r j , A s2r j , B s2r j , where A s2r j and B s2r j represent the maintenance level reduction and maintenance part transition, respectively, and are estimated via (18) and ( 19) based on the initial maintenance strategy l s2r j .…”

“…Based on the fruitful achievements on equipment-level maintenance, fleet-level maintenance possesses practical significance and has drawn much attention [16], [17]. A fleet denotes a group of machines at the same or different working locations that share the common maintenance resources [18]. Fleet maintenance enjoys wide application background such as buses [10], [19], flight [20], wind farms [21], [22], or aircraft maintenance [23], [24].…”

Level of Repair Analysis a Tool for Integrated Optimization: A State of Art Review

“…Rawat and Lad (2016) proposed a LOR analysis model to optimize the reliability design of the multi-indenture system. Additional, A model to optimize the decisions of repair considering the preventive maintenance strategy proposed by Rawat and Lad (2017). The next section discussed the integrated optimization of LOR decisions and spare level considering fleet maintenance system.…”

A review of asset management literature on multi-asset systems

“…Sriram and Haghani [51] considered a fleet of aircraft as a pool from which any plane can be assigned to any origindestination (OD) route and maintained under the equivalent intervention level. Other advocates of this form of fleet are, for instance, [52], [53], and [54].…”

“…Despite its various usage, the term 'fleet' employed by both industry and academia tends gravitate towards a set of patterned features. Hence, improving upon the explanations given by Monnin [53] and Rawat [54], we establish a modern definition of the term 'fleet' in asset management as follows: repair and replacement activities) can be applied to any asset in a fleet.…”