Application of system dynamics tools to model 24-hour metro systems: integration of system engineering and operation management

Considering the growing demand for railway transportation, especially metros, and the changing social context, regular 24-hour operation is becoming a requirement. The railway is an inherently complicated and complex system and extending the service hours increases the level of difficulty in operating. In order to run all the services safely, punctually and reliably, we have to manage this complexity. In this paper, the authors suggest the application of system dynamics tools to model 24-hour metros in terms of sub-systems, sub-components and behaviour. An initial causal loop diagram (CLD) has been developed to study the relationships and interactions between different sub-systems of system. The proposed causal loop diagram is intended to allow planners, designers and managers of 24-hour metros to develop a proper understanding of the non-linear environment of such systems. In metros, due to the high level of diversity and variability, there are many system interfaces that must be managed systematically. Causal loop diagram empower managers to understand the effect of their decision-making in managing the interfaces and related changes. The causal loop diagram can be applied as a system optimisation tool when upgrading the existing metros to 24-hour operation and developing new lines while considering risks, complexities and complications. Causal loop modelling allows a rapid identification of the problems of 24-hour operation and will result in safer, more punctual and more reliable system.