Simulation Approach to Optimise Stockyard Layout: a Case Study in Precast Concrete Products Industry

The precast concrete products industry supplies 2,000 to 4,000 of different products to the construction industry. The demand for the products is seasonal. The industry builds up the stock in winter to meet the high demand in summer. As large numbers of products varying sizes and weights are involved, different handling and stacking requirements, the process of deciding appropriate locations to stock the products and track them while loading into lorries for dispatch becomes complex. Due to lack of appropriate methodology to manage stockyard layout, the industry experiences space congestion for both the storage and dispatch of products on the yard. During dispatch process, greater retrieval time is required, long queues of lorries (shipping vehicles) are formed, and desired level of service cannot be maintained. This paper describes an ongoing research that addresses the stockyard layout management problem through 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, first prototype model development and the strategies used to develop an integrated layout evaluation simulation model.