What are the disadvantages of real time information?

Real time information is data that is made available to you in real time, i.e. as it happens. For example, a system which monitors incoming flights on a given airport might transition an incoming flight through states like "in the air," "on approach," "landing," "landed," "at gate," "awaiting bags," "bags in hall." In a real-time system, the status of each flight would change as it happens, or within a short time after the event. An alternative, not real-time, approach to such a system would be to update the status of all flights once every five minutes, for example.

Real-time information has no disadvantage per se, but most end-users would expect that any system in-between the data source and the consumer (e.g. a display of incoming flight status in the arrivals hall) can cope with the demands of real-time data.

This requires that all components relaying this data, and acting on this data, must be able to handle this data in real time, i.e. in a manner such that the accumulated processing delays remain negligible. Depending on the nature of the data, on the processing requirements and the frequency of change, this can have severe design implications for the participating components.

In modern banking, the availability of real-time information is widely accredited with several financial crisis that occurred within the past decade: since brokers could see transactions and rate changes in real time, responses were much faster as they would have been with slower data. This allowed to hectic response and panic reaction, leading to severe financial crisis in several stock and currency markets.