Regarding Fixlet execution time

Could anyone help me understand the reason for Fixlet execution time.
sometimes the Fixlet takes 10 minutes to execute and sometime the same Fixlet take 15 mins. And for different server the execution time is different. Why is that so?

I’d start by checking through Troubleshooting Client Reponsiveness and begin by checking on the client side of the server. Check the client logs to see whether it is being notified of the new action (the UDP notification), how long before it begins executing the action, how long until the action is complete, and how long until its next report is posted to the Relay.