Track 2 Session 8
2:40 to 3:50 p.m. Thursday April 12, 2007

Impact of Testability and Logistics on Rail System Availability and Maintenance Cost

In this presentation, we plan to describe the experience of ALSTOM Transport Information Solutions with issues of testability, maintenance strategy and logistics, on both main lines (ERTMS) and mass transit applications.

High availability and low maintenance cost (or more generally low life cycle cost) are key requirements in today's complex rail systems, both in mass transit and main line applications. This is especially true for signaling and train control systems. A usual approach to achieving high availability is through redundancy. However, a number of questions related to testability, maintenance strategy and logistics arise. In this session, various maintenance policies will be compared, using Markov and other models, and a sensitivity analysis of system availability with respect to technical and logistical factors will be presented. In particular, using Markov models, the very high sensitivity of availability to failure detection probability will be demonstrated.

Key Words: Testability, Maintenance, Logistics, Availability, Life Cycle Cost