Time constraints in an effective cyber attack?

Since the military doctrine of being fast and precise proved to be working very good. The question arose for its application in the cyber space. In order for some group (no matter of its motivation or affiliation) to conduct an attack on multiple systems simultaneously causing enormous damage, time is of essential importance. One such example is the Slammer worm, that hit servers running Microsoft SQL Server 2000 and in the first 10 minutes did 90% of the damage. The worm disrupted intenet in Japan and Korea, slowed airline reservations, credit card networks and automatic teller machines in U.S. and phone services in Finland. This isolated case proves that if a short time constrained attack may cause a lot more damage than separate attacks conducted over some longer period of time. Also, time constraint is crucial since in order to be most effective, one has to launch attacks on multiple systems in very short time in order to prevent backups from taking over or leaving some part working.