Comprehensive Approach to Allocate Reliability and Cost in Passenger Rail System Design

Rail system design and procurement comprise the process of identifying, acquiring, selecting, and purchasing the right products to form a rail system. To acquire a new system, various products with specific costs and reliability for each subsystem and corresponding components are chosen from equipment suppliers. Planners must carefully examine the trade-offs between life-cycle cost (LCC), system reliability, and service reliability to allocate resources optimally. This study developed a comprehensive allocation process with four types of optimization models for passenger rail system design: (a) maximization of system reliability, (b) maximization of service reliability, (c) minimization of LCC, and (d) minimization of a combination of service unreliability (delay cost) and LCC. On the basis of the characteristics of a passenger rail system and possible alternatives, the proposed process can allocate LCC and service reliability optimally to determine the ideal investment plan for rail system design. Empirical case studies have demonstrated that the proposed optimization process and models can evaluate efficiently and successfully all possible alternatives and determine the best allocation among all subsystems and corresponding components. This comprehensive approach can help users identify the ideal balance between cost and reliability to achieve an optimal rail system design