A GASP IV model of steel ingot processing

Abstract

This paper describes a GASP IV model of part of a steel mill. The processes modeled include pouring molten steel into molds, removing (stripping) the hot ingots from the molds, and sending them to the soaking pits and finally to the primary rolling mill. Molds move from a preparation area to the furnaces, thence to the stripping cranes, and back to the pre paration area. Rail trains transport ingots and molds.

The major problem is how to dispatch a limited number of rail engines to pull trains so that materials and molds are at the right places at the right times for efficient operation. A set of 32 experiments (indi vidual simulation runs) was devised to find an opti mum combination of number of engines, number of transportation zones, and dispatching rules for a particular steel mill.

The set of experiments showed (not surprisingly) that the use of a single transportation zone (so that all engines were able to go wherever they were needed) and a larger number of engines resulted in the greatest percentages of on-time deliveries and (somewhat surprisingly) that random and priority selection of engines worked equally well and were better than selecting the nearest engine, even when that choice was modified by a priority rule.