Fastest, multiple simulation for Mike 21

Dear Mike21-users,
I am going to run 4 simulations in Mike21. Which is the fastest way to finish all of them? Do you suggest me to run them in parallel or should I run the simulations one or two at a time?
The model is grid-based.
Thanks for your advice,
Johanna Sörensen

My experience is run only 1 simulation at a time and wait until it finish to run another. I usually make a .bat file in order to do it

Thank you very much. Do you know where I can read about how to setup the .bat-file?

You can find the instructions here : http://tips.dhigroup.com/default.asp?module=MIKE+ZERO&ID=257

Here is an example:
You can make a file for instance Run.bat then edit this file like this in order to run 4 simulations alternately

"C:\Program Files (x86)\DHI\2012\bin\mzlaunch.exe" "D:\SIM\sim1.m21" -x
"C:\Program Files (x86)\DHI\2012\bin\mzlaunch.exe" "D:\SIM\sim2.m21" -x
"C:\Program Files (x86)\DHI\2012\bin\mzlaunch.exe" "D:\SIM\sim3.m21" -x
"C:\Program Files (x86)\DHI\2012\bin\mzlaunch.exe" "D:\SIM\sim4.m21" -x

Perfect! Thank you.