Hi Experts,
Please give me some suggestions to archive the following goal.
I have an approval process, in this process I have an autoactivity which creates a case log and records some information like this,
Sender- user A, receiver- user B, Action- sent for approval.
Then I have a one manual activity. After the manual activity I have another activity which updates the case log, if the task performer approves the task or rejects it records that information and updates the case log.

The performer of activity 1 is defined based on a process variable and actually I pass the value to the case log as well.So far everything works fine.
The problem is that if the performer of activity 1 is unavailable the case log does not work as expected.The results looks like to this, lets say, "User B has approved bla bla" in fact the user B was not available by the time so it is delegated to user C, and the performer was C not B.
Ok, now what I want to do record the delegation fact as well in the case log, so please give me some suggestions.
How can I check if user B is available or not? I have several options but want to know your advice.
Thanks in advance