Rake Management System (RMS)

The Rake Management System (RMS) is a set of utilities and tools designed for analysis and decision making to do with the overall use of physical train units (rakes), their deployment, maintenance and cycles for suburban train services. The RMS also provides other useful information like occupancy profiles of trains at terminals, platforms and sidings and is therefore useful in other activities in operations planning, such as time-tabling, maintenance planning and crew scheduling.

The RMS consists of the following parts:

Rake Linker: It routes rakes to the services so that total number of rakes used to run all the services is optimal and also the total distance run by all the rakes is optimal (this is done by minimizing empty-rake movements). The core of this module is a minimum-cost flow Network flow optimization formulation which models the various linkage possibilities and assigns costs to them and picks the "best" overall set of linkages. The linkages include empty movements and movements to and from car-sheds and terminals.

Post-processing: It summarizes the information about stabling lines movements, car-sheds movements in accordance with the availability of stabling lines and also optimizes the total distance run by the rake in these activities (for example, if there is more than one car-shed and if the rake can be moved to any of them then these movements are optimized). It also generates the occupancies of the rakes at every station and track.

Rostering: After the daily optimization of total number of rakes used to run all the services in the timetable and total distance run by them, rostering is used in assignment of rakes to the starting services of the day so that average weekly distance is covered by each rake and each rake is assigned to weekly maintenance activity during some day in the week. So it is the total overall weekly optimization of the uses of rakes in conjunction with Rake-Linker and Post-processing.

Occupancies: After the rake cycles, stabling and car-sheds movements are generated by Rake Linker and Post-processing, it generates the occupancy profiles of the rakes at every station and track with platform and track preferences which is further used in checking the feasibility of the platforms and tracks availability and feasible assignment (done by a Platform Allocation algorithm). If all the occupancies are feasible then it generates the final assignment of the platform and tracks to every service and these are then charted in a visually convenient form.

Perturbation and sensitivity analysis: After the rake cycles are obtained from Rake Linker, its goal is to find out some critical services if any so that by modifying some parameter values for these services, a rake or an empty run of a rake can be saved. This can be run in more than one step in order to minimize number of rakes or minimize the total cost of the network The parameters which are considered for modification are turn-around time at the terminus, running time of the service, preponement/postponement of the timings.

Crew Scheduling: After the RakeTable is obtained from Rake Linker, it assigns the crews to the rakes in accordance with several crew constraints.

Maintenance Activities: There are many different types of maintenance activities of the rakes like weekly maintenance, biweekly maintenance, mid-life rehabilitation, end-life rehabilitation etc.

The RMS is therefore an attempt at providing a comprehensive set of tools for exercise of rake deployment for services, and maintenance. At the moment, efforts are underway to implement incremental parts of the system on the suburban system in Central Railway and Western Railway in Mumbai.

A detailed document on the RMS and its use, prepared by Jugal Garg, is here.