Humans began programming computers using coding forms and punched cards. With just a few compilation cycles per day, there was plenty of time to study the listings and look for those elusive bugs. But, now we all write programs at the keyboard and compile them as frequently as we like. So , current day programmers are busy coding and overlooking too many bugs. Later the bug is found, the more is the bug-fixing cost. So currently the developers, are able to write hundreds of lines of code in a day, but only with hundreds of bugs :-(.