  Recently, extensive efforts have been made on the application of expert
system technique to solving the process planning task in the machining domain.
This paper introduces a new formal method to design CAPP expert systems. The
formal method is applied to provide a contour of the CAPP expert system
building technology. Theoretical aspects of the formalism are described and
illustrated by an example of know-how analysis. Flexible facilities to utilize
multiple knowledge types and multiple planning strategies within one system are
provided by the technology.
