Pitch Expert-an engineered collection of specialized knowledge structures

An expert system is described which diagnoses pitch related production problems in the kraft type of pulp mill. Pitch is a sticky material which forms deposits in pulp mills. Pitch Expert, a knowledge-based trouble shooter for pitch problems, operates under a heavy set of constraints imposed by the combination of the expertise itself and the operating environment of pulp mills. To satisfy these constraints, specialized structures and mechanisms were developed and refined to achieve a custom fit. These structures and constraints aid in the maintenance and continued addition of new knowledge to the systems. The utilization of this approach has led to a knowledge-based system with which both the domain expert and the end-users feel comfortable. The result is that the number of mills using this system is growing rapidly