So I had to compromise with  operational research work, which had the intellectual challenge  that interested me and the commercial value  that was valued by the clients: things like scheduling freight trains, time-tabling buses, stock control, lots and lots of stock control.
Tive que comprometer-me  com o trabalho operacional de investigação, que tinha o desafio intelectual  que mais me interessava e o valor comercial  valorizado pelos clientes: coisas como marcar horários  dos comboios de carga, horários dos autocarros,  controlo de "stocks",