Monitoring project types have a schedule built into the Project Properties that you can specify.
You don't have to rebuild the wheel with your monitoring project. You can basically open a brand new monitoring project, then on the pallette of your decision project, do a Select All (Ctrl-A) and Copy (Ctrl-C). Then paste (Ctrl-V) into your new monitoring project. If you had any external libraries you added to the decision project, you have to add them to the monitoring project before you do this.
Then just specify a schedule in Project properties and you're off (top tree node in the tree view - Publishing tab - under Schedule)
The workflow engine is basically responsible for triggering monitoring projects once they're deployed, acc. to the schedule specified.