Development of a hazard analysis technique for human computer systems

Human error is known to be responsible for approximately 80% of all system failures within industries such as aviation, power generation, and mining (Hollnagel, 1993). Many of these errors can be traced back to the design of the human-computer or human-machine system. For example, the London Ambulance Service installed a new computerised dispatch system in 1992 resulting in lengthy delays in the dispatch of ambulances to emergencies (Finklestein & Dowell, 1996). A number of the errors were caused by a slow human-computer interface in which exception messages were not prioritised, queues scrolled off the screen with no means of retrieval and duplicated calls were not identified. In order to overcome these types of design problems, a range of techniques have been developed to analyse the potential for human error within safety-critical systems, and to examine the consequences of errors for the system as a whole.