(3) auto-sorting, and (4) delivery. The purpose of this study
is to design order picking warehouse to minimize the number of transporters and the expected travel time to
improve the performance of transporters. To solve this problem, we developed a mathematical model and also
we demonstrated the system performance by simulation model using AutoMod simulator (Auto Simulations,
2000) and verify the results to compare mathematical results of the system performance of warehouse system.
One of the significant changes in warehouse systems design is the optimizing design and automation of
order picking facilities such as optimizing the performance of order picking transporters to reduce the freight
terminal process cost and increasing the system throughputs. Brynzer and Johnsson (1995) summarized the
factors that affect the performance of order picking system, including the composition of orders in a batch,
the sequence in which the items will be retrieved, where to store each item, the division of the picking area
into zones, layout design, and picking equipment. Roodbergen and Koster (2001) considered a parallel aisle
warehouse, where order pickers can change aisles at the ends of every aisle and also at a cross aisle halfway a
long the aisles. This paper focuses on the performance evaluation for optimizing the performance of transporters
for the design and layout factors of integrated order picking warehouse system. A systematic approach is
introduced for the performance evaluation considering mathematical and simulation methods as: (1) a mathematical
model to analyze the performance of order picking warehouse system and the transporters performance
evaluation. The travel time of transporters is one of the warehouse performance measures and it has
to meet the required throughput considering the design of strip and stack doors. We develop a performance
evaluation model based on the material handling cost for both cases of throughput and waiting due to
congestion and (2) we develop a simulation model using the AutoMod simulator, and we validate the mathematical
model using this simulation model. Fig. 2 shows a systematic approach for order picking warehouse
performance evaluation.