Hi Ratnakar,
you have to define the logic in application system create and delete the old parameter during the change update triggered by actions or in update task of EM EH logic required to delete or reset the old parameter values .
Rule set activity triggered only if you report the events from application system or external system. better to include the logic in application system or explore the EM BADI ( /SAPTRX/BADI_EH_S) options.
~Sukumar
