A simulation model to manage and optimise stockyard layout: A case study in precast concrete products industry

The precast concrete products industry is experiencing space congestion, and long vehicle waiting times on stockyard for both the storage and retrieval of concrete products due to lack of proper methodology to manage the stockyard layout and operations. The demand for the concrete products is seasonal and huge stock is built in winter for dispatch in summer. As large numbers (2000~4000) of products with different sizes, weights and handling and stacking requirements are involved, the process of deciding appropriate locations to stock the products and track them while loading into lorries for dispatch becomes complex. This paper describes an ongoing research that addresses the stockyard layout management problem through the development of a simulation model, which investigates the effects of using different layout scenarios and handling equipment on the performance of stockyard. A prototype model is being developed using ARENA/SIMAN, a general-purpose simulation language. The model integrates production and forecast schedules, evaluates "what-if" scenarios with different layout, product allocation to storage locations and order picking policies. The performance of stockyard is evaluated through vehicle waiting time, vehicle queue lengths, stockyard space utilisation and the cost of storage and dispatch of products. This paper presents the simulation modelling concepts, input data analysis using a case study, first prototype model development and the strategies used to develop an integrated layout evaluation simulation model.