From Open Risk Manual


Backlog. a) The amount of work that accumulates when a system or process is unavailable for a long period of time. This work needs to be processed once the system or process becomes available and may take a considerable amount of time to process. b) A situation whereby a backlog of work requires more time to action than is available through normal working patterns. In extreme circumstances, the backlog may become so large that the backlog cannot be cleared.