While you can add a physical delay, I'd still aim towards finding something more dynamic.
So, this internal process. What does it do? Does it update an SQL table? Create a file? etc? As Marsha_R suggested, if you were doing this manually, how would you know the internal process is complete? Would you click on something, check a value, and then wait and repeat the process?
The reason why I'd not do a physical delay is two-fold:
1) The process may take LESS time on some iterations through the test than you have the delay set for which would mean that you would have an automation process sitting doing nothing for a time when it could be continuing the process.
2) The process may take MORE time on some iterations through the test than you have the delay set for which would mean that you could end up with an invalid test because you didn't wait long enough.
So, finding a dynamic way to check the process and determine if it's complete will minimize the idle time of your process while allowing for long potential delays by setting a maximum timeout.