Energy Freight-Transportation Network

The need for energy freight transportation derives from the significant distances between energy's production and supply point and the consumption point. Whether it is petroleum or the downstream products of it such as gas and gasoline, a trans­portation system must move and deliver it to the final point to meet demands Therefore, the transportation system requires carriers to use any appropriate means to facilitate the delivery of energy at such distances. Another reason for using vari­eties of carriers would be the need to move energy according to schedule, in reli­able containers, with the lowest possibility of happening hazards, and in reasonable costs while meeting the quality standards to satisfy consumer demands. Achieving this aim requires that the components of transportation system operate properly.

A transportation system can be defined as a set of elements and the interactions between them that produces both the demand for travel within a given area and the provision of transportation services to satisfy this demand. Many elements operate in every transportation network, so identifying and controlling all of these interact­ing elements in order to design and implement the network is hardly possible. Therefore, it is inevitable to isolate the elements that are relevant more to the prob­lem being studied and to keep the remaining ones as external factors.

Leveis of Planning

In general, transportation systems are classified into three levels, according to the planning level of the system: strategic, tactical, and operational. Because a trans­portation system has close relationships with management decisions and policies and is a complex organization of components from human and material resources to facilities, infrastructures, carriers, and containers, it is necessary for such system to be planned in detail.

Strategic Level

Long-term planning—or, in other words, strategic planning—is directly concerned with the design of physical network and related models of transportation and its evolution, allocating the location of terminals, ports, and the same facilities; the expansion of transportation capacity; and tariff policies. It determines the general policies and the development trend of the system in the long-term horizon. Therefore, strategic planning involves the highest level of managers and may need large capital investments to be executed.

Knowing that transportation networks are not just national but in many cases international, strategic planning is also done at national, international, and even regional levels. As discussed previously and as elaborated on in "Route" section, models of transportation networks are designed in the strategic level of planning- 451

Tactical Level

Over a medium-term horizon, tactical planning determines resource allocation and utilization in order to make the system operate efficiently. Medium-term planning includes carrier scheduling and routing, and it is responsible for the design of net­work service. The decisions for this level of planning are taken by medium-level managers of the organization.

Operational Level

Performed by local and operational management, this level of planning is con­cerned with the issues happening in the short term. In today's rapidly changing environment, time has an important role, so scheduling and implementing carriers, services, crews, and maintenance activities and efficiently routing and allocating carriers and crews in the short term are the problems that operational managers have to deal with.