Robust hybrid designs for real-time simulation trials

Real time simulation trials involve people and are particularly subject to a number of natural constraints imposed by standard work patterns as well as to the vagaries of the availability of individuals and unscheduled upsets. They also typically involve many factors. Well thought-out simulation experimental design is therefore especially important if the resulting overall trial is to be efficient and robust. We propose hybrid experimental designs that combine the safety of matched runs with the efficiency of fractional factorial designs. This article describes real experiences in this area and the resulting approach and methodology that has evolved from these and which has proved effective in practice.