Inventory Policy not running on new devices

We have our Full Inventory Policy set to run once a month but new machines are not running when they are first added to the system. They are only running at the scheduled time which could be weeks away depending on when the device is added. Since Run Once ASAP is no longer an option how do you set this policy up to run a full inventory when the machine is added to the system?

BTW, We are running SMP 7.1 SP2 MP1.1