Application of Computer Simulation for Productivity Improvement of Welding Unit in a Heater Manufacturing Industry: A Case Study Based on ArenaSalman Jameh Abrishami, Mohammad Zeraatkar, Rasoul Esrafilian, Seyyed Amir Vafaei and Seyed Mojib ZahraeeMATEC Web Conf., 225 (2018) 01004DOI: https://doi.org/10.1051/matecconf/201822501004