A modeling and simulation of production process in subassembly lines at a shipyard

Abstract

In order to simulate material flow in a subassembly line at a shipyard, the product, process, and resources are modeled for the subassembly process. The subassembly line is selected from a large shipyard and consists of several subprocesses, such as base joining, piece alignment, tack welding, and robot welding processes. The analysis and modeling procedure were carried out using the Unified Modeling Language (UML), an object-oriented modeling methodology, and Integration Definition (IDEF), a functional modeling tool. Initially, the characteristics of the shop resources were analyzed using the shipyard data and the layout of the subassembly line was designed with the resources. A production process was then modeled using the resources and the layout. The production process modeling of the subassembly lines was performed using the discrete event simulation method. Using the constructed resource and process model, the productivity and efficiency of the line were investigated. Variations in the resource performance, such as a new welding robot and the number of workers, were examined to simulate changes in productivity. It can be seen that bottlenecks occur in different places according to the nature of new resources. The proposed model is viewed three-dimensionally in a virtual environment so that space allocations for the resources and interferences between objects can be easily investigated.