Soft – the usefulness of a result degrades after its deadline, thereby degrading the system's quality of service.
An example can be software that maintains and updates the flight plans for commercial airliners: the flight plans must be kept reasonably current, but they can operate with the latency of a few seconds. Live audio-video systems are also usually soft real-time; violation of constraints results in degraded quality, but the system can continue to operate and also recover in the future using workload prediction and reconfiguration methodologies.