I was not travelling this weekend, but had family delayed at LGW and eventually canx. I know FlyBe tried to fill the gaps because I heard about the efforts from someone on the inside, but the family had the usual lack of info and they were sitting in the terminal.
Every carrier now asks for email and mobile (cell) phone number as standard. So ...
Firstly: Send an SMS to the pax warning of possible delays. This can be done automatically by a computer and is old hat technology. Even a standard PC running an SMS gateway application with the right network connection from your data centre, could generate 158 msgs (a 734?) in less two minutes and then the various networks will have them out in less than five. YES some pax won't have their phone on, or with them, or have lent it to granny - that's their problem. When the SMS is sent, the computer logs the receipt form the network, so you can prove the time that the pax mobile phone network had the msg.
Second: Pull up the expected pax list and immediately see (on screen) who has OLCI'd and then phone them to ask where they are and what their situation is.
Third: Check who has not OLCI'd and see if they are in the terminal and done a local check in.
Fourth: Look at your list of pax that are in the terminal and waiting from other flights and SMS them to come to the desks.
The carriers (not just BA, to let Bealine off the hook!) can allocate the phone task to a couple of staff who take half the list each and work through it. Perhaps some back office staff can do this, as front line staff will be overrun by folks at the desk.
Don't expect the pax to call in - because they will land up with a busy tone, or talking to a call centre in another country. Get the staff at the departure airport to call the pax.
Having worked in telecommunications, data centres and call centres for 25 years I know that it is a piece of cake. A standard plan is drawn up and then you just implement the computer to SMS the numbers you took when you booked the pax, making it clear why you want the number.
Example:- passing through the new terminal at MUC on LH two years ago, they changed the gate after I had checked in. Guess what? I got an SMS to tell me.
Sorry Bealine, I know that you are well intentioned and doing your very best. But your employer does not always do the same.