If you mean "do pigs have to be retrieved manually"? The answer is, no. Pigs can be automated. You'll still need a way to isolate the pig launcher and catcher, because pigs wear out and need to be changed and, as we all know, things go wrong sometimes.
Kandan: In short, no. One does not always need isolation valves. I just finished putting in a pipeline with L&R's without isolation valves. The key is that the service is water, being pumped from a canal to storage tanks, AND operations willingness to take the pumps offline (thus removing the source of the pressure). It also helped that the L&R were higher than the buried line!
I am going through a similar issue now and according to our client a double block and bleed is required on our recivers and launchers. So it depends on who you are doing the work for or what your company's standard practice is
If it is water, the 'headache' is minor, compared to the explaining your company has to do in case of gasoline, crude, fuel oil or some other toxic/flamable product spill to stake holders, press, government and neighbors.
It does depend on the pressure rating of your system.
What normally we used, for liquid system having 600# and above, a double block and bleed valve is required.
For gas system, for system having 900# and above, a double block and bleed valve is required. If H2S in the gas stream is high (SOUR Service), system having 600# and above, double block and bleed valve is required.