Production planning application for a PET resin production plant

PET (Polyethylene terephthalate) is one of the most important aromatic polyester commercially. Therefore, number of PET production sites has increased at a great pace all around the world as time passes due to its extensive usage. Subject of this thesis is developing a production planning model for one of bottle grade PET production plants in Turkey. Production planning is very critical for PET resin production facilities especially in Turkey, because there are only three manufacturers and sum of their production quantity is lower than actual market demand. According to the actual data of the year in which the planning was made, the amount of PET resin imported in bottles is 49.1% of the total PET resin consumption in bottles. Facilities of the study alone is capable to do the Turkey's bottle grade PET production of 47.5%. As shown by these data, an improper production planning would affect especially domestic consumers and sectoral current deficit would be increased due to rising imported PET quantity. This kind of plan must be prepared considering sustainability to decrease environmental impact by sufficient production and effective use of resources. For these purposes, a deterministic multi-period multi-product single level mixed-integer linear programming (MILP) model is presented. The objective is to maximize profit. The proposed model is applied for different choices in inventory policy, energy resources policy and capacity policy. It was seen that significant improvements were achieved according to obtained results. According to findings profit increases by 6.0% and total cost decreases by 6.8%.