Integration of RAMS in LCC analysis for linear transport infrastructures. A case study for railways.

Álvaro Calle-Cordón,Noemi Jiménez-Redondo,Johan Odelius,F J Morales-Gámiz,F A García-Villena,Amir H S Garmabaki

doi:10.1088/1757-899x/236/1/012106

Abstract

Life-cycle cost (LCC) analysis is an economic technique used to assess the total costs associated with the lifetime of a system in order to support decision making in long term strategic planning. For complex systems, such as railway and road infrastructures, the cost of maintenance plays an important role in the LCC analysis. Costs associated with maintenance interventions can be more reliably estimated by integrating the probabilistic nature of the failures associated to these interventions in the LCC models. Reliability, Maintainability, Availability and Safety (RAMS) parameters describe the maintenance needs of an asset in a quantitative way by using probabilistic information extracted from registered maintenance activities. Therefore, the integration of RAMS in the LCC analysis allows obtaining reliable predictions of system maintenance costs and the dependencies of these costs with specific cost drivers through sensitivity analyses. This paper presents an innovative approach for a combined RAMS & LCC methodology for railway and road transport infrastructures being developed under the on-going H2020 project INFRALERT. Such RAMS & LCC analysis provides relevant probabilistic information to be used for condition and risk-based planning of maintenance activities as well as for decision support in long term strategic investment planning.

Highlights

Railway and road network infrastructures are quite complex systems which components have a very long technical lifetime (40 to 120 years, see e.g. Ref. [1]) and are subject to different failure
Such RAMS & life-cycle cost (LCC) analysis provides relevant probabilistic information to be used for condition and risk-based planning of maintenance activities as well as for decision support in long term strategic investment planning
Annual Corrective Maintenance Cost The costs derived from CM assume failures in the system that lead to replacements or repairs of the components

Summary

Introduction

Railway and road network infrastructures are quite complex systems which components have a very long technical lifetime (40 to 120 years, see e.g. Ref. [1]) and are subject to different failure. Annual CM and PM cost can be modelled as follows: Annual Corrective Maintenance Cost The costs derived from CM assume failures in the system that lead to replacements or repairs of the components. In this plot, each event, represented by a point in time, corresponds to a CM action associated to a switch restoration. To calculate the TimeTo-Failure (TTF) and Time-To-Restore (TTR) after failure, each of the different components needs to be analysed independently using probabilistic models. When building the LCC model, one of the most difficult pieces of information to obtain is the cost per action As it has been stressed, here we will focus on modelling cost for S&C restoration associated to replacement of components for which RAMS parameters are available. In our case we will model replacement cost using the following equation:

K N 1

Findings

Conclusions