Customized simulation interface for packaged gas warehouse design

The objective of this paper is to present the prototype of a software package embedding a simulation tool, customized for optimizing the facility layout of packaged gas warehouses. In those warehouses, empty packages are filled with different kinds of gases. To accelerate the filling process, pallets of similar packages are prepared in so-called sorting areas, while assorted pallets of filled ones are composed to fulfil the clients' needs. The main challenge for the authors' industrial partner is to be able to answer its customers' demands in less than 24 hours, while reducing the production costs. These costs have several sources: the numbers of packages within the system, creating stocks but also occupying significant space, the layout of the different areas and their interactions (internal transport, buffers, etc). Simulation has proven to be an efficient tool to help the designer to study the problems related to interactions between process and space. The philosophy of the prototype, called "depot layout editor", is to focus on the description of the architecture of the warehouse, while the simulation itself is left to a commercial package, AUTOMOD(TM). Once the warehouse (or part of it) has been described, the software generates the simulation code, which can then be run within the AUTOMOD(TM) environment. One of the advantages of using an external simulation kernel is that it provides extensive statistical analysis tools to evaluate the performance of a given design. The main feature of the approach is to be able to quickly test several architectures and organizations in order to find the one that best suits each warehouse constraints: geometry of the building, availability of stocks, customers' daily orders, etc. This paper will present the several aspects of the simulation preparation (products, process and layout definition), as well as the results obtained on several warehouse simulations studied for validation.