The synthesis of a real-time diagnostic expert system to monitor plant
performance and identify faults in the event of process failure as we
ll as signal potential failures is described. The crucial features whi
ch have been included are system reliability, use of dynamic trends in
data and parameters to identify problem as well as the ability to han
dle complex knowledge. The emphasis here is on how a dynamic simulator
is used to incorporate a learning algorithm based on a fuzzy set cove
ring method for formulating a knowledge model of the operational chara
cteristics, which enables debugging and testing of the system to be ca
rried out continuously. The procedure is illustrated by reference to t
he operation of refinery crude oil distillation columns. (C) 1997 Else
vier Science Ltd.