Thank you for you answer,
do you have, by chance, any examples related to the suggested solutions?
I forgot to add the fact, this flow will be launched via dedicated portal where users select various parameters and click a button to start the process.
I thought about using a job, equal to pgm2, with _action=background, as a way to launch it in asynchronous mode, but I do not how to include the job within the SAS program.