This paper is to analyze the pre-positioning point of storage/retrieval vehicles to minimize the expected response time within the aisles when items are retrieved as the batch size in an automated storage/retrieval system. The pre-positioning point of the vehicle within aisle is the location that the vehicle stays when idle. The dwell point is the location that minimizes the expected response time from the dwell point to the first retrieval location of the batch size retrieval. The products are requested to be retrieved as the batch size in AS/RS, then they are retrieved as the sub batch size within each aisle. The batch size are divided up into the sub batch size in each aisle. The retrieval batch size in the aisle is variable. The mathematical model for the expected response time from the dwell point to the first retrieval location of the batch size retrieval is analyzed. The solution procedure to find the dwell point that minimizes the expected response time within each aisle is developed. And a numerical example is shown to explain the solution procedure.