SR and it's 6 division s simply replied for any new trian introduction /extension that Coaches are shortage in division.
So production of Coaches have to be increased and totally stopped exports. After fulfilling the demand s the exports has to be resumed.
Nowadays, so many trains are delayed operation which also needed higher number of coaches. Stand by standardized coach set of trains have to be kept at major Terminal, so as to operate train services in time without waiting g for the delayed arrival of...
more... the corresponding train or Rack Sharing Arrangement train.