It was during his PhD studies that the concepts of formal methods of minimizing energy usage were devised, with his supervisor, Dr John Flower, and developed in a series of papers beginning in 1978.
It was during this time that he studied for his second PhD, his thesis was entitled "Pinch Technology" in which the concepts of minimizing energy usage were devised and put into practice. His work was developed in a series of papers beginning in 1978.