This paper describes the development of inferential models for the provisio
n of real-time, on-line estimates of the quality of a breakfast cereal for
production line operators. Five quality variables were selected and on-line
measurements reflective of the key process conditions were identified. Fol
lowing process data logging, a number of linear and non-linear data-based m
odelling methods were applied to identify relationships between the on-line
measurements and the product quality. Off-line verification of the models
indicated that the prediction accuracy achieved was sufficient to offer the
opportunity for quality control improvements. The models were subsequently
implemented on-line to provide the process operators with frequent estimat
es of product quality. Performance assessment has indicated a reduction in
the variability of all five quality parameters. In addition to details of t
he modelling, the decisions relating to the development strategy and justif
ication for implementation are considered. (C) 2001 Elsevier Science Ltd. A
ll rights reserved.