Best practice would be to use the Blue Prism standard templates that have retry loops in sub pages, these are explained both within the Template instruction documents and in the exception handling training.
If you want to retry after a period of time then maybe you should be handling your system unavailable exception to put items back into the work queue defered for a set period of time so that they are tried again later - you would need to ensure your processes are using queue status to skip any updates that have already been performed.
All this is standard exception handling design which your training mentor should be able to discuss with you.
