Implementation of LCC strategies
Summary
A high-performing rail infrastructure must be upgraded and maintained based on a comprehensive programme which seeks to optimise costs and meet demand.
The ÖBB switched to life-cycle cost (LCC) strategies for reinvestment and track maintenance in 2000-2002. Since then this approach has been further expanded and updated. The basic procedure will be explained by experience-based standard elements. As early as 1998 research into the behaviour of track geometry was launched with the aim of developing a mathematical model as only such a model provides the kind of data needed to predict maintenance requirements and service life. These predictions, in turn, are necessary to shift from corrective maintenance to preventive maintenance. 2011 was the year in which the ÖBB moved from LCC-based strategies to life-cycle management (LCM). Since then all major reinvestment projects have been assisted by the LCM unit (composed of an LCM team of the Graz University of Technology and another one of the ÖBB). The Graz University LCM team identifies the optimum time for reinvestment by comparing reinvestment with further maintenance based on annuity monitoring. This approach also includes the examination of chosen components for their conformity with the existing strategy and the determination of an optimum length for the work site. A database is used for these purposes, which primarily analyses the time series of track data (as provided by track recording cars and by other information) in cooperation with the project manager. An example of such an assessment will be discussed.
To ensure cost-optimised and needs-based infrastructure management under a comprehensive overall programme, ÖBB Infrastruktur AG has streamlined the process flows of maintenance, shortened the decision-making processes and optimised asset management by the introduction of proactive life-cycle management. The next important step will be to regard infrastructure as an integrated railway line that involves different work disciplines, i.e. focus on an overall line perspective rather than on the individual contracts awarded to these work disciplines.
The LCM department has launched pilot projects, which take forward the successful path of track LCM to include the whole line and all its work disciplines in order to optimise construction costs and minimise operational hindrances. This will lead to the establishment of the ‘integrated line perspective-based LCM model' designed to integrate and further develop the analysis and interpretation of basic data as well as the model for system ageing of all systems provided by different work disciplines. This concept is based on an integrated life-cycle model, which can be adjusted to the individual scenarios of concrete tasks and was originally designed for PPP models. It provides predictions of changes in the condition of individual line elements, the focus being on ageing models and deterioration curves for railway track and substructure, engineering structures, traffic control and signalling systems as well as traction current supply systems.
Predictions are made for each structure/component depending on its type, design, make, age, documented maintenance condition and applicable standards and requirements. Probabilistic methods are used to determine the variance of condition development in order to calculate the upper and lower limit of prediction in terms of sensitivity analysis.