Work Practice Simulation of Complex Human-Automation Systems: The Brahms Generalized Überlingen Model

We describe a design verification and validation methodology for assessing aviation safety. The approach involves a detailed computer simulation of work practices that includes people interacting with flight-critical systems. The Brahms Generalized Uberlingen Model (BrahmsGUM), was developed by analyzing and generalizing the circumstances of the Uberlingen 2002 collision scenario, which can be simulated as a particular configuration of the model. Simulation experiments varying assumptions about aircraft flights and system dysfunctions/availability revealed the time-sensitive interactions among TCAS, the pilots, and air traffic controller (ATCO) and particularly how a routinely complicated situation became cognitively complex for the ATCO. Brahms-GUM also revealed the strength of the Brahms framework for simulating asynchronous (or loosely coupled), distributed processes in which the sequence of behavioral interactions can be unpredictable. The simulation generates metrics that can be compared to observational data and/or make predictions for redesign experiments.