Process is stuck in the middle in oracle flexcube

I’m developing a process flow for a client which needs to be done in oracle flexcube.
when i run the process sometimes it runs without any error and sometimes it’s stuck in the middle. I used wait for ready(complete) to avoid loading problem and also used “delay”. I am still facing problem. I can not seem to find any error in my process. Also is there any way for mapping certain elements for type into activity in this? because the elements sometimes changes its position.