Human-Initiated Failures and Malfunction Reporting

Two studies were conducted to determine the extent and nature of human-initiated failures in missile systems. The first study1 compared malfunction data obtained from written reports with data gathered from interviews with line and supervisory personnel. The study revealed large discrepancies in emphasis and extent of data between the reporting methods. Written reports generally were concerned only with failed equipment; interview data with operational, near, or possible malfunctions. The results indicated that personnel tend to report human-initiated malfunctions as equipment malfunctions, thus avoiding incrimination of themselves or their fellow workers. The second study2 attempted to establish the extent of unreported human-initiated malfunctions. Examination indicated that in individual missile systems, human-initiated malfunctions comprised from 20 to 53 per cent of all system malfunctions. It was also revealed that in two missile systems, human-initiated holds accounted for 16 and 23 per cent of total holds, respectively. Human-initiated malfunction data were further classified into the kinds of operations in which these malfunctions occurred. The percentages in these classifications are indicated in this report. Malfunction-reporting practices were reviewed to establish their effectiveness in revealing these data and to indicate the way in which the reporting schemes serve, or fail to serve, the problem of indicating human-initiated malfunction in order that corrective action may be taken.