The scheduling of an ethylene cracking furnace system should not only focus on the plant profitability but also address the concern of environmental sustainability. On the basis of the previous study (Zhao et al.'), this Article has developed a new scheduling model for the optimal operation of the cracking furnace system in ethylene plants by considering more practical operating features, such as nonhomogeneous last-batch ending times and furnace load makeups, as well as the background air-quality conscious decoking. With the newly developed model, the simultaneous furnace shutdown can be successfully avoided at the end of the scheduling time horizon; meanwhile, certain manufacturing capacity losses and upsets can be alleviated during furnace decoking operations. Furthermore, the obtained scheduling solution will be responsible for background air-quality concerns by wisely allocating furnace decoking emission peaks into time windows that would cause less adverse environmental impacts. The efficacy of the developed model has been demonstrated by a comprehensive case study.