Kawasaki Heavy Industries, Ltd of Japan put a scheduling system for section mill finishing facility lines applying a constraint-oriented knowledge processing system in field operation.

The scheduling component is part of the control system in Kawasaki-built steel facilities in Japan and South-East Asia.

The application specific software and the constraint solver called KIS-V (Kawasaki Inference System V) was developped by Kawasaki engineers using IF/Prolog procured from IF Computer; platform is real time DEC Alpha/VMS machines from Digital Equipment.

"We implemented the constraint system in Prolog - then what used to be 70.000 lines of C code with if-then-else statements came down to 30 lines of contraint declarations" said Shigeru Ihara, Manager of the System Engineering Section at Kawasaki Heavy Industries.

Some aspects of the system and its operational effectiveness have been published e.g. at SICE-96 in Tottori, Japan and at the Third World Congress on Expert Systems in February 96 in Seoul, Korea.

The papers detail the applicability of the method to avoid blocking, deadlocks etc in multi-purpose machine flow scheduling, control of automated guided vehicles and other resource allocation tasks essential to efficient use of complex production lines.

Kawasaki reports that scheduling for a finishing facility line with 3 cold saws and 5 inspection beds was better that human expert produced plans and that the development period of the knowledge base for the system is only about 1/10 of the effort previously required by human domain experts to develop hand-written tables.

For a closed loop traveling system with 5 vehicles and random requests for travelling, the system reduces vehicle idle time by 60% and increased capacity by 145%.