Petroleum Refinery Planning

Abstract

model.A key characteristic of scheduling operations is the dynamic and extensive information required to describe the system. Customer orders, resource availability, and manufacturing processes undergo relatively rapid changes, resulting in a compelling need for efficient management of information and resources.Planning problems can mainly be distinguished as strategic, tactical or operational, based on the decisions involved and the time horizon considered (Grossmann, van den Heever and Harjunkoski, 2001). The strategic level planning considers a time span of more than one year and covers the whole width of an organization. At this level, approximate and/or aggregate models are adequate and mainly consider future investment decisions. Tactical level planning typically involves a midterm horizon of a few months to a year, where the decisions usually include production, inventory, and distribution. Operational level covers shorter periods of time, spanning from one week to three months, where the decisions involve actual production and allocation of resources. For a general process operations hierarchy, planning is at the highest level of command. As shown in Figure 2.1, enterprise-wide planning provides production targets for each individual site, where each site transforms the plans into schedules and operational/control targets.Despite the differences, it is obvious that production planning, scheduling, and operations control are all closely-related activities. Decisions made at the production planning level have a great impact at the scheduling level, while the scheduling in itself determines the feasibility of executing the production plans with the resulting