Simulation and optimization model of the Signoff units in order to increase the logistic productivity and reduce the production and quality costs: A Case Study in Saipa Automotive Company

In the present research, an optimization process was performed in Signoff unit of Saipa Corporation based on the discrete event simulation using a multiple objective function. The required information, including the operation classes (product inspection, adjustment, and reworking), the flow between different workstations, operation times, production cost identification, etc., were extracted from the actual data recorded for March 2018- March 2019 period. For the purpose of simulation, firstly, the model was built using the Arena software and all effective parameters and variables were introduced into the model following the planning of various scenarios. Upon a predetermined number of iterations, the bottleneck was identified and the model was verified. Next, in a primary phase, the OptQuest software was utilized to find the optimal number of workers for minimizing the production costs after 378 iterations (upon satisfaction of an automatic stop criterion), and the result was used as input for a secondary phase where the model was optimized for enhancing the operational capacity of the logistic units upon 303 iterations. Using the results of this research, it was anticipated to achieve 21.6% drop in the number of Operator along with 10% increase in the logistic capacity, 4% reduction in the production costs, and 2% increase in the production rate.