Conveyor scheduling system for a feeds manufacturing plant: A case study

A feeds manufacturing plant produces various feed types, each of which requires as many as 12 major ingredients. The ingredients are poured from ingredient silos. The silos, in turn, are filled by a network of six conveyors. This system addresses the conveying stage. Given a day’s production requirements, it generates a corresponding schedule which ensures that materials are available at the silos when needed while minimizing conveyor idle time due to ingredient changeovers and waiting. The algorithm is applied to the first conveyor which can carry the most urgent ingredient. After a complete feasible schedule is composed for the first conveyor, the algorithm is applied to the succeeding conveyors. Meanwhile, ingredient requirements and silo balances are updated throughout the process. The initial feasible conveyor schedule provides an upper bound on changeovers, i.e. during evaluation, schedules which reach the upper bound are dropped from further consideration. The upper bound is continuously replaced with a schedule with less changeovers. The system is currently installed on a PC/XT microcomputer.