Enhancing hot mill slab yield, usage and throughput using expert systems and numerical optimization

The new Oregon Steel Mills (OSM) Order Application System (OASYS) blends expert systems methodology (match and rank slabs to orders) and numerical optimization technology (optimize slab burning, yield, throughput and roll round planning) to maximize the hot mill slab inventory value. This paper examines the system`s underlying technologies, its current status, and how it will operate. The OASYS will: (1) Analyze slabs not yet scheduled for rolling and determine to which orders they may be applied. If multiple combinations are possible, rank them by the user-determined preliminary match preferences (partial solution using rule-based methodology). (2) Determine the best set of matches between slabs and orders utilizing slab burning, as appropriate (global probabilistic optimization). (3) Provide a rolling round for the rolling mill (local solution using the savings algorithm). (4) Provide assistance with melt planning by showing the number of tons of each steel grade necessary for orders but not available in inventory. (5) Provide maintenance facilities to view and modify parameters. This allows the system to easily adapt to changes in business or operating conditions. Planning for a rolling mill consists of defining rollable slabs and specifying their combination into roll rounds. These functions are handled by the burning optimizationmore » and roll round planning functions within OASYS.« less