<h1> Representing The Impact of Time on Human Error and Systems Failure </h1> <h2> <a href="http://www.dcs.gla.ac.uk/%7Ejohnson">Chris Johnson</a> </h2> <h4> <a href="http://www.dcs.gla.ac.uk/research/gaag">Glasgow Accident Analysis Group</a>,<br> <a href="http://www.dcs.gla.ac.uk">Department of Computing Science,</a><br> <a href="http://www.gla.ac.uk">University of Glasgow</a>,<br> Email: <a href="mailto:johnson@dcs.gla.ac.uk">johnson</a>@dcs.gla.ac.uk </h4> <h2> Abstract </h2> <p> Time plays a central role in our understanding of human error and system failure. Without a detailed knowledge of the flow of events, investigators cannot hope to arrive at accurate and well founded conclusions about the causes of major accidents. This paper argues that existing approaches, such as time lines and fault trees, cannot capture the sequencing and synchronisation constraints that characterise complex human-machine failures. We, therefore, present requirements for future accident modelling techniques that will capture the temporal properties of accidents. </p><h2></h2>