Modelling with UML Activity diagram a program that update a system timer

Question

I'm trying to model an application with UML, and need some help.

The program starts every 60 seconds by a system timer.
The program is started with an argument called Type
The first time the program i started after a system reboot, the program is started with argument 1.
The program do what i should do, and get a new Type
The program update the system timer so that the next time the program is started, it get the new Type as argument.
The program then ends.

I'm thinking of modeling this with an activity diagrams, but do not know how.

I made the following experiment. Is that correct, or is it something that needs to be changed or can be improved?

My first try

Why is BX1 parallel? do you allow more than one instance of the program to be active at one stage? — vainolo
BX1 is an executable program, so basically you can start any number of instances of the program. But in reality, only one instance of the program running at a time, so maybe it is wrong to mark it as paralell. Enterprice Architecture demanded that I chose Parallel, iterative or stream. But I might be using it the wrong way? — magol

vainolo vainolo · Accepted Answer · 2012-10-02T09:01:50

Instead of using a parallel region, you should have one activity that has internal activities to depict your program. Something like this:

compound activity

What you depict in your diagram is that the region inside the dotted line receives multiple inputs and processes them in parallel. Not what you want.

The OS part seems OK to me.