i successfully applied escalation rule on activity . but what i need to do is:

i have a process that will complete in 48 working hrs ideally. i want to apply escalation on process level so that if process cannot complete in 48 hrs, than process terminates itself. so that no activity can perform after 48 hrs.

If you are using Blackpearl, process escalations are supported.  If you open your process in visual studio there is an icon that looks like a clock in the top right hand corner (just like the activity escalation icon).  You can configure process level escalations there, in a similar fashion than the activity level escalations.

 If you want to terminate the process, I suggest creating an empty server event activity right at the end of the process (you can call this "Process Finished").

You can then use the action template Goto activity to go to this activity.  This will end the process instance.

If you do use K2.net 2003, process level escalations are not supported, but you do have options to get around it.  Let me know if you need them.

Apologies, I can see from the forum you are using k2.net 2003. 

What you can do for process level escalations in K2.net 2003 is to create an activity with a server event (you can call the activity process level ascalation).  Change the server event to syncronous false (I think) so that the activity does not complete.  You can connect the activity with a line from the start icon, so as the process start, the activity is activated.

If you want to terminate the process, I suggest creating an empty server event activity right at the end of the process (you can call this "Process Finished").

You can then configure your escalation on this activity and in your escalation action, expire the actitvy and then make the process go to the above mentioned activity.

This should do the trick.