Comment by Shinolove

I work on ATC software in another country. In my experience the biggest hurdle is the way the software is being developed and sold. ATC authorities and service providers buy these systems as a product but they don't have the code. Developers of the products (people like me) constantly have to maintain different versions deployed all around the world for different areas or countries or service providers. And there are hundreds of different systems working in parallel for no reason. For example there is an airport with 5 runways here and they installed a specific software just to monitor the speed and altitude of the planes taking off from this runway. They already have 5 different survelliance monitors feeding this info as well as direct view from the tower. Every new software now also has to consider and integrate with this specific system and many like it.