How to show simultaneous processes

I have Visio 2003 Standard.

I need to show processes occurring simultaneously. For example, in a
telecommunications industry call center environment, a call comes in and the
customer’s system is down. Our procedure is: begin remote diagnostics,
dispatch a technician, and notify the project manager. All of these things
happen simultaneously (via automated workflow).

Not sure how to represent this on a Visio diagram.

Any help is greatly appreciated.