Procedures in complex systems: The airline cockpit

In complex human-machine systems, successful operations depend on a elaborate set of procedures which are specified by the operational management of the organization. These procedures indicate to the human operator (in this case the pilot) the manner in which operational management intends to have various tasks performed. The intent is to provide guidance to the pilots and to ensure a safe, logical, efficient, and predictable (standardized) means of carrying out the objectives of the job. However, procedures can become a hodge-podge. Inconsistent or illogical procedures may lead to non-compliance by operators. Based on a field study with three major airlines, the authors propose a model for procedure development which we call “The Four P's: ” philosophy, policies, procedures, and practices. The various factors, both external and internal to the cockpit, that must be considered for procedure design are presented. In particular, the paper addresses the development of procedures for automated cockpits—a decade-long, and highly controversial issue in commercial aviation. Although this paper is based on airline operations, we believe that the principles discussed are also applicable to other high-risk supervisory control systems, such as space flight, manufacturing process control, nuclear power production, and military operations. I