This thesis describes research into the behaviour of process loops in a glass-melting furnace at Redfearn National Glass, Barnsley. The objectives were to ascertain methods of determining improved control strategies and to study in detail the furnace parameters affecting fuel consumption. An initial survey of the literature showed a lack of consensus over the best methods to adopt, but from certain sources a basic methodology was taken. An improved methodology was derived and this was employed to identify the characteristics of the major loops.