B757-200
Dispatch Dispatcher
Communication Breakdown; Confusion; Troubleshooting; Workload
Deviation / Discrepancy - Procedural Published Material / Policy
General None Reported / Taken
Environment - Non Weather Related; Human Factors; Procedure
I'm only being made aware of the issue today.  Two months ago; I had a flight between two west coast cities. Dispatch view prompted me to add a radio number due to a late inbound flight with the same flight number. Per policy I added radio number XXXT and made the change within Dispatch software and with ATC. Unknown to me the Dispatcher of the inbound XXX had made his flight XXXT as well. Dispatch software does not provide this information and we no longer have a function to tell which radio numbers have already been used or else I could have selected XXXA. Or in reality; had I known the inbound already had a radio number I could have left my leg alone completely. But as the system is set up now there was no prompt so we ended up with two XXXT's at the same airport at the same time. At the time of occurrence I was not aware of any of this. My crew did not report any problems to best of my recollection a month after the fact after having dispatched several hundred subsequent flights.
A Dispatcher reported that after a dispatch software program change he and another Dispatcher were able to assign an outbound flight and a delayed inbound flight the same code while both aircraft were at the same airport.