The multi-objective optimization model for a sustainable manufacturing system design

In the past decade, there has been a growing concern about the environmental protection in the public society as governments in many countries have been enforcing ever-stricter environmental policies and regulations in industry by promoting energy saving and low carbon dioxide (CO₂) emissions in manufacturing activities. Development of sustainable manufacturing systems is considered as one of effective solutions to minimize the environmental impact. Lean manufacturing can also be helpful for achieving a sustainable manufacturing system as it can reduce production wastes and increase manufacturing efficiency. Nevertheless, the lean approach does not include a consideration in energy consumption and CO₂ emissions when designing a lean manufacturing system. This paper addresses these issues by evaluating a sustainable manufacturing system design by considering a measurement of energy consumption and CO₂ emissions. To this aim, a multi-objective mathematical model is developed incorporating the economic and ecological constraints in terms of minimization of the total cost, energy consumption and CO₂ emissions for a manufacturing system design. The study also addresses a decision making in the number of machines, the number of air conditioning units and the number of bulbs involved in each process of the manufacturing system in conjunction with a quantity of material flow for processing the products. A real case study was used for examining the validation and applicability of the developed sustainable manufacturing system model.