Though initial plans for a railway system were made in 1832, it was only in 1844 that any track was laid. That slow start belied the speed of things to come. Just six years later, the rail network covered 14,500 kilometers. Today, the Indian Railways has over 623,000 km of track linking about 7,000 stations. Driving this growth is the number of passengers and freight that want to use the railway's services.

As more trains rode the rails and new systems evolved, newer and faster trains like the Shatabdi, for example, needed drivers with different grades of skills. Hierarchies became common. Assistant drivers, assistant shunters, assistant everything were born. Positions on trains also became more specialized as brakemen, guards, and other positions etcetera were introduced. And that's only staff on a train. An entire ecosystem was required to maintain tracks, work the signals, man stations, inspect locos, etcetera.

To keep crew fatigue at bay, the Indian Railways introduced rules to ensure that crew members got rest -- complicating the process of assigning duties. Even today, those in-charge of making staff timetables need to guarantee that a driver's mileage is limited to 8,000 kilometers a month. Loco drivers are not permitted to work longer than a six-hour stretch, allowing them to do 'doubles'. Over a fortnight, crews cannot work more than 104 hours. At the same time, each crew-member needs an average of 18 hours of rest at headquarters or eight hours if they are out-station. The railways also state that 'periodic rest each month must include four 30-hour rest periods, or five 22-hour rest periods.'

The assignment of duties also has to account for drivers who are being promoted and require 33 weeks of on-hands or 'road training' or drivers who need to re-familiarize themselves to routes they worked before (they ride shotgun during the re-familiarization process). Railway managers also need to ensure that certain categories of drivers got rotated every 30 days or so to drive the more 'prestigious' trains and remember that drivers for goods trains could double as drivers for passengers trains (only in special cases).

Complexity became the order of the day.