Solution Time Calculation Problem!

[irba]

Hello,

I'm using OTRS 3.2.2 on linux system.
I have created a dynamic field called Fault Occur Time to keep information about the exact time the problem raised (as ticket might be opened later and the ticket's Creation Time is not correct to be used instead ).
What I'm looking for is some way to calculate the solution time (that appears in Ticket Information) based on SLA and Fault Occur Time and not based on SLA and ticket's Creation Time.
Is there any way to achieve it?

Thank you in advance!