BUS606: Operations and Supply Chain Management

This paper proposes a new idea and a method regarding the layout problem. In previous studies, the correlation between the industrial area and a single plant has rarely been considered. To fill this gap, the coupling relationship of these two layout scales are focused on in this work, which will certainly lead to a better result. To reach a coupling layout planning, three steps of the optimization are carried out in sequence. The key plant with the greatest impact is selected according to the variable e. It is then modified in a multi-floor structure with plenty of constraints and the objective function, which is the total cost, including piping investment cost, pumping operating cost, land cost and floor construction cost. Both the cross-floor placement of towers and reactors and the constraints for the placement of specific facilities are considered. Finally, the original and modified key plant are separately optimized with other plants. The land cost is the objective function in the optimization of area-wide layout. Diagram and numerical comparisons are reached for the analysis of the coupling optimization. A refinery served as an example to verify the proposed methodology. A better solution was achieved. Case results show that even though the plant cost after the modification is 141,400 CNY/a higher, there is a 1,947,500 CNY/a reduction in the area-wide layout cost. When the key plant is coupled with the industrial area, the final total cost is reduced by 1,806,100 CNY/a, which turns out to be a significant improvement.

When studying the area-wide layout in the future, this method can be used to figure out the plant that has a greatest influence on the whole layout. The time value of money will be involved as well to reach a more valuable result. The internal modification of the key plant itself can bring great benefits to the whole industrial layout transformation, which saves resources and capital costs to a great extent. This method provides reference and a new direction for the retrofitting of a plant or a whole industrial area.