They may also be “planning to diagram”, which is to say that you try and avoid wholesale changes to diagram structure (to save time and effort) and plan your trains accordingly.
Depending on your diagram structure, recasting services can be a nightmare because, although the train pathing is easy, making the crew work isn’t.
I have some sympathy with their position because planning north of the river in strike circumstances can’t be that easy. It’s not something that can be done in a few days, because of the interactions with other TOCs.
I had some sympathy as it is difficult to organise multiple changes for different types of strikes but.....
From Redhill, we normally get 4 to the core and 2 to Victoria. Victoria's have all gone (bar some very early morning) - then 1 of the 4 to the core is going through and 1 other terminating at London Bridge (2 peak services go through to Bedford), the other 2 have gone.
Lack of Management thought means GTR decided to use a pair from same half hour meaning the other half hour is fully unserved and hence the 50 minute gap.
How hard would it have been to use the opposite half hour diagram of the core service to serve London Bridge making an even service - I suspect not very hard. No new diagrams just one that it is used every day!
Also, the smaller stations are reduced to one train an hour. So Merstham and Coulsdon South have gone from 4 (6 at peak) trains per hour to just 1. However that 1 is so full before it arrives that people cannot physically get on (local Rail Rep was at Coulsdon South to see multiple trains and estimated 150 plus could not get on train) - remember this is a 12 coach Class 700! and then they have an hour to wait for the next one! Meanwhile at least 1 more service goes through half-empty because it is in a diagram that doesn't call at this stations.
Yet, when you suggest to GTR adaptions to services to sort this out, they say there are no planners available to sort it out and they hope they maybe able to get to it if there are future strikes. A year ago they would have worked hard on this but they appear to lack any willingness to help now.
Meanwhile Passengers are very frustrated and my sympathy has waned.
I can pin these management failings to starting precisely when a certain manager left GTR.