Start tasks as early as possible

It seems like tasks do not default to starting as early as possible - for example if I link a group of sub-tasks end-start they snap into the correct consecutive order but if I then unlink them they remain in that order instead of returning to a simultaneous start, artificially increasing the project duration. The only way I’ve found of moving each one to be start as soon as possible is to edit each task begin date and enter a early than possible date (say a year) - then the task will move to the correct position, governed by its summary task predecessor. I cant find a setting anywhere to get tasks to start as soon as their master task will permit, doing this for each task after changing a link elsewhere is error prone and very time time consuming. Linking each task start to start would also take a very long time as they all have to be done one at a time as far as I can work out. Any tips please ?

You can achieve this up to some extent using “earliest begin” field. This screencast demonstrates how to use it:

Thanks Dmitry, I’ll give that a try.
A global project setting to always start tasks as soon as possible would be a nice feature to have in the future.