Minimizing Human-Machine Interface Failures In High Risk Systems

Technology now permits the building of very complex man-machine systems with centralized controls, with the result that many processes can be run by relatively few individual workers [ 11. Studies of failures within these complex systems indicate that they are usually the consequence of a series of highly complex coincidences. There is an institutional neglect or misunderstanding of the implications of low-probability, high-consequence events [2] for the design of complex man-machine systems. Bhopal, Challenger, Chernobyl, the Swiss Chemical Spill, the Exxon Valda, Seveso, Tenerife Alrplane Crash, Three Mile Island-incidents like these emphaize the need to better understand the mechanisms of disasters in complex, high-risk systems. Hardware failures are the best understood component of failures in such systems. Software has historically been less well understood, but great strides are presently being made in understanding interactions between software design errors in these systems. Human error is the most complex and least understood factor in the failures of complex systems,