Hi Vijetha,
A bit of searching around revealed the following document:
http://www.altera.co.uk/literature/rr/rr.pdf (
http://www.altera.co.uk/literature/rr/rr.pdf)
This discusses the reliability of several device families, including MAX V. However, it does specifically focus on data retention and not necessarily all failure modes.
Have a read and see if it answers your questions. I also suggest you put this question to your local Altera rep or distributor for them to answer. This forum offers a lot of experience as a result of putting these devices to use but not necessarily specific knowledge of the device testing data that Altera will have access to.
Regards,
Alex