Remember that you need to be careful when you design robotics as a services as the solution may not scale without adding too much bots.
When using robotics as services you need to consider different factors:
1.- The execution time that the robotic automation may have. If too long your service will be really slow or may even time out.
2.- The expected number of concurrent requests. All the request will be sequenced and queued. If you have 50 requests but you only have 1 bot and the automation takes 1 second. The best scenario will be that only 1 user will get the response in 1 second, another in 2 seconds, and so on until the last one that would get the response in 50 seconds after waiting for all the other requests to be attended.
This said, if you still want to go ahead with the implementation. Pega Robotics uses Work Queues. The same bot can subscribe to one or multiple Work Queues and these can be prioritise using Robot Manager. The robot won't process assignments from the next queue until all the assignments in the higher priority queue have been processed. However, the priority can be adjusted at any time during the work session.
Another approach would be to use scheduling to control when the robot works on which queue. This can be done by defining multiple work groups with one (or multiple work queues) instead of one with multiple work queues.