It would appear that many people don't fully understand crew rosters........
Different brigades work things differently - and rosters are not all the same.
I know of some brigades that roster, so that everyone gets a chance to go out to a call, rather than the same few people always getting out, and the same people always missing out (and sometimes the ones that get out all the time do so because they may as well be living at the station!!)
For others it means you are on roster, and need to respond to anything that occurs..but if you are not on roster, you don't have to go anywhere. Flexability exists so that if you know you can't respond on a given day, when you are on the roster, you organise a swap with someone who can.
This type of roster also ensures that a truck will get out of the door on all occasions.
And while on the subject of crewing, some brigades, particularly those in perhaps a busy regional centre, rather than put major stress on their own members by having to respond to a relatively high number of calls, they identify members from other brigades, who are perhaps working in the Regional centre, who are capable / suitable, and approach them to respond with that regional centre brigade - ensuring a good day time response, and enhancing brigade relations etc etc... lots of good things out of it....
Pip