SYSTEM TESTING ALGORITHM AND APPARATUS

Method and apparatus for determining deficiencies of an aircraft or avionics system (4, Fig. 2) comprising providing first inputs (2); processing the inputs (8, Fig. 2) to produce corresponding outputs (4); determining a function value for each output that indicates how well the system performs (6) when processing the corresponding input (8, Fig. 2); and using the first inputs and the function values to generate second inputs that correspond to maximum or minimum function values, where the maximum or minimum values indicate poor system performance. The process for generating the second inputs may be iterative and may comprise a genetic or an evolutionary algorithm, a simulated annealing process or a neural network, and may involve performing a crossover, recombination and a mutation process (12) on the first inputs. The system being tested may be for collision avoidance, route planning, decision making and may be a non-deterministic, black-box or a white-box system.