Decision Factors in Service Control on High-Frequency Metro Line Importance in Service Delivery

Service control-the task of implementing the timetable in daily operations on a metro line-plays a key role in service delivery, because it influences the quality of the service provided to passengers. Shortfalls of previous research on the role and importance of service control have been noted. A framework intended to remedy some of these shortfalls is proposed. An important element of this framework is the description of the full decision environment in which service control takes place. On the basis of insights gained from extended visits to a control center, the reliability of the system is found to depend on many endogenous factors. These factors were not previously recognized in a comprehensive manner by either researchers or practitioners. Aside from the objectives of maintaining adequate levels of service from an operations perspective and minimizing the impact of schedule deviations on passengers, the management of crew and rolling stock, safety, and infrastructure capacity are major considerations in service control decisions. Given the uncertain environment in which service control operates, a strong preference was observed among controllers for manageable and robust control strategies. An example is discussed in which service controllers react to two similar disruptions with different recovery strategies, mainly because of crew management considerations. This research demonstrates the importance of a comprehensive understanding of the objectives and constraints faced by service controllers in daily operations.