I'm new to modelling and have an issue for my assignment.

I want to model the basic process in a hospital. The case is actually something else, so please don't think too much into it. A level 1 model with the "happy" path would be, after a regular patient came in:

1. Handle incoming patient at reception (receptionist)
2. Heal patient (medical employees)
3. Record results into database (receptionist)

Then the receptionist has multiple tasks.

1. Taking care of incoming regular patients. Inside there is a "check in patient", where the receptionist calls a patient and checks them in.
2. Sometime other duties arrive, like handle the mail, for which the receptionist interrupts the actual work for a moment(but logically either before calling the patient or after the patient is checked in), and resumes afterwards with the whole process (I'm not sure where to resume)
3. Also the records need to be done a few times a day. This is done, when, at some moment there is no patient is in queue. But patients can come in during this time and have to wait for a moment (model this?). Also at the beginning of the day, records, which were false the day before, need to be redone.

Modeling the patients flow is not needed and the XOR percentages are not relevant for now.

I have so many issues here, and clearly miss some understanding, maybe I think too much into it, but I need a solution. I'm not sure, how to decompose correctly, choose the right start events, the right exceptions, how to let the receptionist move back and forth with recording the records and more.