ow we can increase the execution time of a PHP script?

I have given you some function using them you can increase the execution time of a PHP script.Default time for execution of a PHP script is 30 seconds.
These are,
1.set_time_limit()//change execution time temporarily.
2.ini_set()//change execution time temporarily. 
3. By modifying `max_execution_time' value in PHP
configuration(php.ini) file.//change execution time permanent.