The effectiveness of a simulation program, that combines the computational efficiency of algorithmic procedures employed to deal with tightly structured information, with the transparency and the flexibility of heuristic procedures employed to deal with loosely-structured knowledge, is investigated. Applications in manufacturing engineering are considered, since the "intelligent" direction, provided by the integration of robotic devices for factory automation, is suitably simulated by embedding the governing modules, built with AI tools, into special purpose programming facilities, developed as CAD and CAM support. The effectiveness of the mixed algorithmic and heuristic procedure is shown in an example application. A generalized and improved implementation is the object of further developments.