ABSTRACT
Complex aircraft systems are frequently developed that fail to meet expected performance requirements. Performance requirements are traditionally based on a specified system functionality. Quality in a system is a form of conformance to requirements. In most failed cases performance shortfalls can be partly attributed to aircrew related problems inherent in the design. Recognition of these problems has prompted a search for improved system specification methods. This article argues for the early consideration of the appropriate human functions, within early system functional specification, in order that human performance requirements might be more fully appreciated by system designers. If human system related functions and performance cannot be adequately specified, then it is unlikely that any effective electronic advisory assistance to the human operator can ever be effectively specified.
