At what spot,we can say that"this is the Crash point".

Crash point basically mean when no or less response,error starts coming along with the warning,but say"at one time no response is coming,and little errors are also starting coming,but in a bit,again response comes,passed request but along with errors and warning(Continuously)

So at first point where there is no response,that is crashing point?or again when the response has come,errors are also coming ,overall fluctuating results are coming,So the question is again"Where is the crash point".

Thanks.