Line capacity estimation, timetabling and other applications of simulation and optimization tools for railway operations

1. Line capacity estimation, timetabling and other applications of simulation and optimization tools for railway operations planning Narayan Rangaraj Sudhir Sinha Seema Ramteke Industrial Engineering and Operations Research IIT Bombay

2. Overview of planning • Strategic problems • Capacity planning (infrastructure) • Tactical problems • Timetabling • Fleet planning • Crew scheduling • Operational problems • Train control • Dynamic scheduling • Dynamic pricing (revenue management)

3. Strategic decisions (railways) • Current railway framework • LRDSS (Railway Board), Railplan (MRVN), etc. • Our work • Definition of capacity on railway section • Capturing congestion effects and broad scheduling strategies • Medium term capacity investments in signalling • Trade off between throughput (number of trains) handled and transit time (average)

4. Strategic decisions (railways) • Robust capacity: capacity in the presence of failure • Signaling failures modeled and impact on train running quantified • Simulation used as a tool for analysis • Line capacity studies done in Secunderabad-Kazipet section as part of tool development for IRISET, Secunderabad • Virar-Dahanu Road section as a test section for automatic signaling on main line sections • Extensive studies on Central Railway main line and harbour line sections on the suburban network in Mumbai

5. Railways (capacity analysis) • Simulation for line capacity analysis • Reliability vs. capacity Studies on the suburban network for a given corridor Quantify the trade-off between achievable headway and service measures (such as punctuality and average delays suffered by trains) under a given pattern of failure

6. Railways (capacity analysis) • Terminal capacity • Capability of handling trains at terminals • Routing possibilities • Look-ahead period and a routing algorithm applied on an appropriate time-space network • Representation of network from primitive structures identified In the suburban case, trade off established between achievable headway and turnaround time at platforms (e.g. in Mumbai CST station, shown that a headway of 3 minutes achievable for an identified stream of trains, provided that the turnaround time was less than about 4 mins and 20 secs.

7. Tactical decisions (Railways) • Timetabling • Master chart preparation tool for railway planning Java based graphical tool with cyclical schedule generation • Mini-scheduler for conflict checking and minor timetabling changes Java based tool with interface-based verification of conflicts and suggesting first feasible times for activities. Simple algorithms for backward scheduling and combined constraint satisfaction • Scheduler for full-scale timetabling Based on constraint satisfaction tool CHIP Capable of full-scale timetable generation

8. Tactical decisions (Railways) • Rake linking • Long distance trains Coaching stock utilisation (integrated with maintenance schedules at terminals) Timetables as an input • Suburban trains Integrated with timetables Maintenance schedules as an input

9. Tactical decisions (Railways) • Long distance rake linking • DSS which allows views of a common database of • Timetable - origin/destination and timings • Terminal maintenance line charts (pit lines and washing lines - also considering constraints on line length and time for maintenance) • Rake link table (constraints on length of run between two maintenance points and rake compatibility) • Typical patterns of rake linking (self linking, interchange of day trains) • Trains introduced to take advantage of rake link possibilities • Terminals changed to accommodate rake links

10. Tactical decisions (Railways) • Suburban services rake linking • Rake linking of timetabled suburban services is a single/ multi-commodity flow problem • Model helps in • finding minimum number of rakes for a given schedule (big improvement NOT expected, as timetables are generated with rake links in mind) • capturing extent of empty running • generate/suggest changes in operating parameters (e.g. turnaround times for a few services) so that a rake can be saved • Open problem : multi-commodity problem (e.g. 9 car/12 car rakes, DC rakes/AC-DC rakes)

11. Other tactical decisions • Railways: Crew scheduling • Initial system being developed • Bus system (urban): Depot allocation • Variants of the transportation problem in network flows • Bus system (urban): Crew scheduling • Multi-stage heuristics • (e.g. HASTUS) LP for the aggregate problem, • Variant of shortest path for individual work-piece definition from a vehicle-route • (non-bipartite) matching for creation of work days • Column generation

12. Marketing and Pricing models • Railways • Network based models for pricing (based on second shortest distance) • Marketing and service planning (Konkan Railways) • Containers/Trucking • Fleet utilization and locational imbalance based pricing model

13. Other studies • Supply chain view of transport operations • Freight supply chains on Indian Railways • Containerised movement of import export commodities to and from Jawaharlal Nehru Port Trust to the hinterland

14. Summary of approaches • Large set of problems amenable to analysis • Modeling and delimiting the scope of the model calls for a lot of effort and interaction with users • Major O.R. techniques used were Simulation, Network Flow models and Linear Programming, in many variants

15. Three examples • Simulation studies on line capacity, including an analysis of signal failures • A master-chart preparation tool with a scheduling option • Rake linking for suburban services

16. Faculty/professional associates • Marketing applications/network based pricing/Inland water transport - G. Raghuram • Simulation based tools - A.Ranade and K. Moudgalya • Robust capacity – N. Hemachandra • Suburban rake linking, suburban timetabling, network operations and pricing - M. Sohoni • Containerization - N. Viswanadham • Railway operations – A. K. Srivastava and Vasudeva Kamath

17. Ashok Kumar B. N. Vishnu Jugal Garg Kapil Goswami K. Chandrashekar Mitali Johri Prashant Puniya Ravindra Gokhale Rajesh Naik Sadanand Kandalkar Jai Mrug Deepansh Malik Sudhir Sinha Vaishali Moharir Mahesh Shenoy B.C.S.Krishnamohan J. R. Suresh Hrishikesh Karmarkar S. Chandran Priya Mahadevan V. Aneesh Seema Ramteke Amit Arora Manish Garg Students and research associates

18. Publications and conference presentations in this area • N. Rangaraj and M. V. Kamath, "Dynamic operational policies for the Bombay suburban rail transportation system", Journal of Transport Management, vol20, no 2, 1996 • N. Rangaraj and J. R. Suresh, "Decision support for crew scheduling in urban transport", Journal of Transport Management, vol 18, no 3, March 1994 • N. Rangaraj, G. Raghuram and M. V. Kamath, "Are passengers on Indian Railways paying their way? Parts I and II", Railway Fare and Freight Committee (Seminars and studies), Ministry of Railways, Govt of India,1993 • Vishnu Narayanan and Narayan Rangaraj, "A network-based representation of track layouts in railway stations", submitted to Transportation Research, Series B • Narayan Rangaraj, Milind Sohoni, Prashant Puniya and Jugal Garg ,"Rake Linking for Suburban Train Services", submitted to Opsearch • Narayan Rangaraj, "An analysis of cyclic timetables for suburban railway services", submitted to Abhivyakti

19. Publications and conference presentations in this area • N.Rangaraj, A.Ranade, Moudgalya, C.Konda, M.Johri and R.Naik "Simulator for Line Capacity Planning" Sixth Asia Pacific Operations Research Society, Delhi, December 2003 • N. Rangaraj and N. Viswanadham, "An example of a supply chain involving multimodal containerised transport", National Conference on Transportation Systems, Delhi, 2002 • N. Rangaraj and A. K. Srivastava, "Some IT imperatives for Indian Railways in a supply chain management environment", National Connectivity Vision: Surface Transportation and Communication, Indian National Academy of Engineering, Hyderabad, 2001 • N. Rangaraj and A. K. Srivastava, "Network capacity planning and operational control in Indian Railways", National Connectivity Vision: Surface Transportation and Communication, Indian National Academy of Engineering, Hyderabad, 2001 • G. Raghuram, N.Rangaraj and M. V. Kamath, "Network based pricing for passenger services on Indian Railways", Refereed Proceedings of the National Conference on Transportation Systems and Studies, and Railway Fare and Freight Committee (Seminars and studies), Ministry of Railways, Govt of India, 1993

20. Publications and conference presentations in this area • N. Rangaraj,"Quantitative models for capacity planning in transport systems, ORSI Annual Convention, Ahmedabad, 2000 • N. Rangaraj, M. Shenoy and M. V. Kamath, "Application of Constraint Logic Programming to Commuter Train Timetabling", presented at the Australian Workshop on Constraints, held in conjunction with the Australian Joint Conference on Artificial Intelligence, Griffith University, Brisbane,Australia, 1998 • N. Rangaraj, "Timetabling strategies for suburban railway operations", at IT Tracks for IR (seminar organised jointly by IIT Bombay and Tata Unisys Ltd), April 1996 • N. Rangaraj and B. C. S. Krishnamohan, A systematic and quantitative view of capacity estimation and enhancement of the Indian Railway network", ORSI Annual Convention, Bhubhaneswar, 1993 • N. Rangaraj and J. R. Suresh, "Crew Scheduling for urban bus operations", ORSI Annual Convention, Ahmedabad, 1992 • Narayan Rangaraj , "An analysis of Operations, Mode Choice, Pricing and Network Economics of Container Movement", International Workshop on IT-Enabled Manufacturing, Logistics and Supply Chain Management held in Bangalore during December 15-16, 2003

21. Publications and conference presentations in this area • N. Rangaraj and B. N. Vishnu, "Node capacity and terminal management on Indian Railways", Vision 2025, Railway Staff College, Vadodara, 2002 • N. Rangaraj and M. Sohoni,"Meeting transport demands on a network: costs of loaded and empty movements and of waiting", Industrial Engineering and Operations Research, IIT Bombay (2001), also technical report at The Logistics Institute - Asia Pacific, National University of Singapore • N. Rangaraj and N.Viswanadham, "Multimodal containerised transport for export and import through Western India - a supply chain perspective", Industrial Engineering and Operations Research, IIT Bombay, 2001, also technical report at The Logistics Institute - Asia Pacific, National University of Singapore • N. Rangaraj,"A note on section scheduling", Industrial Engineering and Operations Research, IIT Bombay, 1997 • N. Rangaraj and J. Mrug, "A decision support system for rake linking and related operational decisions", Industrial Engineering and Operations Research, IIT Bombay, 1997

22. Publications and conference presentations in this area • N. Rangaraj and M. V. Kamath, "Demand-sensitive schedule generation for an urban mass transportation system", Industrial Engineering and Operations Research, IIT Bombay, 1995 • Konkan Railway Corporation Limited [with B. Banerjee and G. Raghuram],Vikalpa v. 25, no. 1 (2000). • Narayan Rangaraj, Sudhir Sinha, Ravindra Gokhale and Sadanand Kandalkar, Capacity Enhancement of the Mumbai Suburban Railway System through Signaling Improvements: A Simulation Based Approach, Manuscript in preparation • Ravindra Gokhale, Narayan Rangaraj and N. Hemachandra, Railway Line Capacity Evaluation under Influence of Signal Failures, using a Simulation Based Approach, Manuscript in preparation