Dr N.R.S. Tait completed his PhD at Edinburgh University and continued his research at the Department of Physics, University of Liverpool and at the Daresbury Laboratory. He went on to teach at the Centre for Hazard and Risk Management at the University of Loughborough.

While at Daresbury he had responsibility for Health and Safety. Combining this with an interest in the history of technology he undertook research into reliability and accident probability. Updating the Victorian concept of the factor of safety he looked at the use of probability in engineering to ascertain safety, particularly with reference to the work of the aircraft industry which, from the 1930s onward, combined reliabilities of different factors to provide a reliability factor. He used this research to enable him to design failsafe systems at the Daresbury Laboratory.