The problem with regularly calling people before their rostered sby time is that it suggests that the rostering system is not working properly. If the operation cannot be crewed or covered within the current rostering system, then it is the crewing department that needs to adapt and NOT resort to regularly disturbing crew to cover the inadequacies. As commented earlier it would be wise to have a fresh look at sby start times and see if they fit with the current operational timetable.
That said, I agree that it is almost impossible to have the exact number of heads in the right place at all times. That though should only be a result of previous delays, canx, out of hours etc. and not as a result of rostering practice.
The trouble with using the 'you scratch my back and I'll scratch yours' approach is that it almost always works one way. After all in a larger airline how do you repay the favour? So if you are not careful you build up a certain amount of antagonism against you (crewing).
This kind of practice is often most used in airlines where there is a crew compliment that are younger and newer to the industry and afraid of standing up for themselves or unaware of the rules. In this current climate many crew will be very very frightened of causing a possible flight delay or refusal of duty. Crewing do need to be mindful that whilst we live in turbulent times and we must all work together to keep our airlines afloat, it would be very easy to pass their own departments 'weaknesses' onto their crew and visa versa. The crew/crewing relationship is one that needs very careful nurturing to get the best productivity.
We all work in 24/7/360 industry so we all know the disruption that it has on our lives. No-one can sustain working in an industry where your working week is completely at the behest of the employer and you end up with no ability to plan anything away from work. So it is not quite as simple as calling someone who starts work at 0900 to come in at 0800 on the odd occasion.
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