Simulating the first operation in an assembly line

Simulation is a widespread tool for the design and analysis of industrial processes with many software packages available to help develop the model and undertake the analysis. However, when modeling an assembly line in which the first operation draws materials from a warehouse with readily available stock, one problem arises in the representation of this first operation in the model when using available software languages such as GPSS, SLAM, SIMAN. This problem is demonstrated by the loss of the desired statistics generated by the software, the inability of the software to complete the execution of the simulation, or an excessive simulation time that is sometimes terminated abruptly, particularly when using educational versions of the software with restricted simulation power. This paper addresses the problems arising when modeling such cases, the different ways of representing them, and how to overcome the difficulties. It also discusses the merits and drawbacks of each solution.