The Conceptual Design of Flexible Manufacturing System with the Use of Computer Simulation in Enterprise Dynamics

Abstract

Nowadays, production processes become more and more complicated because of global market competition and the need for flexible changes in production in order to meet customer needs. That is related to the frequent reorganization of production systems and require adequate operations management, internal and external logistics, and project management from the stage of conceptual design to the industrial implementation. Currently, we may observe an increased use of automation and robotization, which replace human labor. Modern industrial robots can work similarly to a human operator, but the replacement of a human operator with a robot is related to some technical problems and excessive cost, therefore robotic workstations must be properly designed. The aim of the study is developing a method which allows estimation of productivity growth associated with the replacement of human labor with industrial robots at an early design stage. The production flow in the manufacturing system and internal logistic processes were modeled in the Enterprise Dynamics software, which enables simulation and visualization of discrete production processes. The models were built taking into account availability, performance and quality parameters, which enable a direct calculation of OEE (Overall Equipment Effectiveness) indicator, which is one of most important Key Performance Indicator (KPI) used in World Class Manufacturing (WCM) methodology, especially in automotive industry. The use of OEE indicator enables comparison with similar manufacturing systems. The example of the conceptual design of the flexible manufacturing cell, with CNC machine tools, which can be operated by humans or robots, is presented. The production process includes two machining operations of large and heavy parts, which are difficult to handle, therefore robots are preferred to apply. The computer simulation of the sophisticated model of the flexible manufacturing system with machines, operators and robots with reliability parameters allows better representation and understanding of a real production process at the stage of conceptual design. The experiment results confirm the advantage of the application of robotic operated production systems comparing to manually operated machines with production growth of about 17%. However, robotization is related to very high investment cost, therefore detailed economic analysis is required, including a comparison of labor cost and robot cost. Obtained results can be used for detailed designing of manufacturing systems and robotic workstations.