Thanks for your valuable suggestion. Infact, now I felt, it a little misleading.
The intention of the question is what the probability of success in migrating a package and running without doing any modification is 0% for ActiveX Script Tasks.
However, when one expects to upgrade his package, he does not expect a code that does not work. We expect it to be ready, with the slightest of modifications.
(Wherever he is present, please read as he/she).