Minela Boghossian - Department of Industrial Engineering, Amirkabir University of Technology, Tehran, Iran
Seyyed Mohammad Taghi Fatemi Ghomi - Department of Industrial Engineering, Amirkabir University of Technology, Tehran, Iran

Assembly lines are the most commonly used issue in the mass production of products. An assembly line is where semi-finished products move from workstation to workstation. Traditional studies in the production system are only focused on economic performance, but in recent years greenhouse gas emissions, especially carbon dioxide emissions, have attracted extensive concern worldwide. In this paper, two objective functions which deal with the workload smoothing problem and energy consumption are studied. The aim is to solve the workload smoothing problem which is the sum of processing times of the tasks assigned to the workstations considering the energy consumption used by the machines to decrease the carbon dioxide emission. Considering the sum of two objective functions as the main objective function, it can be concluded that the cycle time and machine parameters are the main factors influencing the minimization of the objective function.

Assembly line; Workload smoothing; Carbon emission; Machine scheduling