if I have 3 therapists and all 3 can do a 60 min massage

Hi, if I have 3 therapists and all 3 can do a 60 min massage at the same time on 8:00am, do I set capacity to 1 on the 60 min massage service or 3?

Does it mean 1 per service or 3 per therapists that can do the service?

Thanks