Masami Konishi

An optimisation model and its effective beam search heuristics for floor-storage warehousing systems

This paper presents an optimisation model and its effective solution technique using beam search heuristic for floor-storage warehousing systems. For a floor-storage system, storage can be accessed from the top of stacks only. The objective is to minimise the number of re-handling operations by optimally determining the storage location and by grouping products for each customer that fit a given sequence for receiving and retrieving operations. An integer programming model is formulated and an approximate solution technique based on the beam search method is proposed to solve the problem by incorporating effective heuristics to reduce the search space using future receiving and retrieving requests. The effectiveness of the proposed method is demonstrated for industrial warehousing problems in a steel plant with 58 storage areas involving more than 3000 retrieving operations. The proposed solution method is shown to be more efficient than the traditional branch-and-bound method for solving integer programming problems.

Agent based operation support system for hot strip rolling

As is well known, an advanced knowledge and know-how of human are needed in the operation support work. Further, human expert can cope with the recent trend of machine dynamics. Usually, the diagnosis works have been privately performed in the brain of the individuals, and its information were not shared. Recently, the number of experts is decreasing and it becomes important to maintain and to extend experts technologies having been built up. For the purpose, the method and the system for technical inheritance of the advanced techniques of the skilled engineers are needed to train the unskilled operators and also can assist skilled operators. In this research, the simulation technology for hot strip rolling mills based on distributed agents and its application to the development of the operation support rules usable for stable operation hot strip rolling mills operation are studied. The agent based simulator can simulate rolling phenomenon considering operating conditions in detail.

An Inventory Control Method for Supply Chain Planning for Single Stage Production Systems under Uncertain Demand

In this paper, we propose an inventory control method for supply chain planning for single stage production systems under uncertain demand. The planning and scheduling model for uncertain demand situation is developed to represent actual environments for planning and scheduling where variances of future demand are gradually available as the time proceeds. In the proposed method, the amount of shipping for raw materials and safety stock for final products are determined by a stochastic approach by using demand average and variation in feedforward. The quantity of safety stock of inventory for final products is determined by incorporating feedback information from the detailed scheduling results. The effectiveness of the proposed methods is investigated from numerical simulations.

Safety Design of Ore Transfer Facilities in Steel Works

In this paper, safety design of ore transfer facilities in steel works is studied. For ore yard of iron and steel works, it is necessary to supply required amount of iron ore via multiple numbers of conveyers. To attain the stable operation of ore transfer, the optimized usage of transfer facilities for continuous transfer. The equalized load distributions of conveyer operations are preferable for safety transfer operations preventing facility stop by fault of the specified facility. A new method of safety design of transfer facilities is developed based on a decentralized agent model. Simulation results by decentralized agent method revealed existence of the appropriate arrangement of the transfer facilities

An inventory control scheme for simultaneous production planning and scheduling under demand uncertainty

We propose an inventory control scheme for simultaneous production planning and scheduling for uncertain demand situations. The stochastic approach accompanied with feedback information from the results of production scheduling is used to determine appropriate inventory amount to maximize the total profit. Numerical results show the effectiveness of the proposed approach.