Assalam-o-alaikum!

FPOE takes place immediately after the completion of STP. It is obligatory to qualify FPOE within 3 attempts, for CONFIRMATION in the service.

Why probationers fail.....

Well, FPOE is really tough. There are usually 8-12 papers (varies among occupational groups).....one paper a day......and everything covered during the STP is included....Problem yeh hoti hai k STP is usually 8 months long....and course ka burden buhat ziyada hota hai....covering 10-12 subjects in 8 months and then appearing for a comprehensive FPOE...it is just like another CSS !

Other reasons vary from person to person......some people don't concentrate; some consider k 3 options hain...pass kar hi lain gay...etc etc.

Usually people do qualify it within 3 attempts.....because, an unlucky probationer doesn't have to repeat all the papers....sirf wohi subjects repeat kartay hain jo last time pass nahi kar sakay thay.
As far as i Know, there has been no such case where a probationer was fired for not making it within the allowed attempts!

ALLAH HAFIZ!
A.J.