On the Optimal Allocation of Three Modes for The Intercontinental Transportation of Seasonal Products

The existence of a worldwide trend that the world\u27s manufacturing site is moving toEast Asia is well known. Very large part of the products produced in these districts are to betransported to the U.S.A. and are concentrated to rather small number of ports, including airports.These situations are causing very serious traffic problems. New products are required to betransported swiftly by air. Once the market demands are stable, the products should be sent ratherslowly but in larger amount. Since the airport of China is quite restricted, transportation cost isincreasing and also the time for transportation is increasing. Here, the third method is appearing.This is the so-called Sea-and-Air transportation. Its cost and time in transit takes a mean positionbetween Air and Ocean freight services. However, there have been existing no reasonable strategyhow to allocate these three methods for the transportation. In the previous paper the optimalcondition was considered under the assumptions that products are transported directly after theirproduction. Here, the same problem is considered under the assumption that all products arealready produced and stored in the inventory. Products are transported following the demands fromthe consuming districts. The most efficient transportation for such case is considered with the helpof simulations

Basic Considerations for the Optimal Allocation of Three Modes Intercontinental Transportation of Seasonal Products

There is a trend toward that world\u27s manufacturing sites are moving to East Asia. After the production, these products are transported to the adavanced nations for their consumption demands. Among such advanced nations, U.S.A. has the largest demand and then Japan and other European countries follow. It should be noted that these Asian districts used for the production sites are rather restricted. Therefore, the volume of products transported from these restricted districts of Asia to U.S.A. is becoming tremendously large. This situation is causing very serious taraffic problems. The new products are required to be transported swiftly by air. Once the consumption and market demands are stable, the products should be sent rather slowly but in larger amount. However, the airports of China are quite restricted and while the amount of transportation is becoming large. As a result, transportation cost is increasing and also the time for transportation is increasing. Here, the third method is appearing. This is the so-called Sea and Air transportation. The cost and time in transit take mean positions between Air and Ocean fleight servises. There ecists no reasonable strategy how allocate these three methods for the taransportation. This paper is an attempt to theoretically describe this mechanism and to find out the optimal result

Optimization of Sea and Air Transportation

In recent years, sea and air transport is becoming a big trend. However, papers concerning sea and air transport can hardly be seen for mathematical formulation and its analysis. In this paper, we make mathematical formulation of the case single supply site and single demand site with multiple delivery dates/different delivery quantities as of a fundamental one. Under certain constraints, minimum cost is pursued. Objective function is expanded from considering transportation cost to considering transportation cost and warehouse stock fee where reduced cost is taken into consideration according to the shortened days to the delivery due date. Simple numerical example is examined. Next, expansion is executed as for the case single supply site and multiple demand sites. Formulation expansion is executed as for the case multiple supply sites and single demand site. By formulating sea and air transport problem, it can be handled clearly and smoothly. Various solving method should be examined hereafter

フクスウモードヲリヨウシタコクサイフクゴウイッカンユソウシステムノサイテキカノタメノキソテキコウサツ

わが国のみならず世界の先進工業国の製造業は、国際的なコスト競争に対処するため、東アジア、特に中国を中心とした海外にその生産拠点の多くを移動させてきた。日本においても、かつては日本から世界市場に供給が行われていた製品が、今日では進出先国から直接世界市場へ供給が行われている。これら製品の海外への輸送手段には従来、航空輸送と海上輸送の2種類の輸送方法が考えられていた。新しい製品は、市場を有効に開拓するため早急な輸送が望まれ、それゆえこの目的のためには航空輸送が用いられた。しかし、航空輸送は高速であるがコスト高であり、量的輸送能力は低い。開拓された市場には大量の製品供給が必要であり、このため大量輸送には海上輸送が用いられた。この両輸送手段の形態と機能の相違は極めて大きい。しかもその相違は、生産貨物の集中激化によりコスト的には増大し、速度的には減少の傾向にある。ここに両者の特長を併せ持つといえるシー・アンド・エア輸送なる手段が登場した。シー・アンド・エア輸送とは、一旦近隣の空港まで海上輸送し、そこから航空輸送をしようという国際複合一貫輸送である。この輸送方式は、中国から世界最大の消費国米国に輸出される商品にとってきわめて有効であると考えられる。日本は、その地理的条件とその輸送形態を構築するインフラを持つ港湾の存在、航空貨物スペースの確保のしやすさ等からシー・アンド・エア輸送の中継地としてその役割を担えると考えられる。しかしながらこのシー・アンド・エア輸送の有効性、さらにはこの3種類の異なる輸送形態の併用手法の有効性は未だ十分な認識をえるに至っていない。本研究の目的は、複合輸送利用者の最適輸送計画のためにシー・アンド・エア輸送の有効性を検討し、最適輸送計画の枠組みを提案するとともに、同時に日本輸送業界の体制改善と活性化に資する情報を提供することにある

Optimization of International Inter-Modal Logistics Utilizing Genetic Algorithm

In recent years, inter-modal international logistics is becoming a big trend. Sea and air transport is a term of inter-modal international logistics. Sea and air transport is developing rapidly in recent years. However, papers concerning sea and air transport can hardly be seen especially for mathematical formulation and its analysis. In this paper, we make mathematical formulation of the case single supply site and single demand site with multiple delivery date/different delivery quantities as of a fundamental one. Under certain constraints, minimum cost is pursued. Next, expansion is executed as for the case single supply site and multiple demand sites. Numerical example is examined and optimal solution is derived using genetic algorithm. Finally, formulation expansion is executed as for the case multiple supply sites and multiple demand sites. By formulating sea and air transport problem, it can be handled clearly and smoothly. Various solving methods should be examined hereafter