This absolutely! I used to see the high level plans at BT for the at the time biggest IBM system DB2 in this case. They planed changes to the system years in a

This absolutely! I used to see the high level plans at BT for the at the time biggest IBM system DB2 in this case. They planed changes to the system years in advance in lock step with changes to the physical plant and incrementally introduced changes. eg release 55 and 56 would introduce stuff that would be used 6 months later in release 58 "Caller ID works on every phone in the country"