Question

During the peak hours ( 4pm−8pm ) on a typical weekday, an order for the in-store shoppers is received every 9 minutes on average. Assume the same time estimates and number of shoppers as in the previous question. That is, it takes 25 minutes on average for a shopper to pick all items on the list, and 15 minutes to check out the items and move them to the staging area; the total number of in-store shoppers is 11. What is the average utilization of a shopper?

Answer 1

To calculate the average utilization of a shopper, divide the number of orders arriving per hour by the total order handling capacity of all shoppers. For the given scenario, it works out to 40.4% utilization during peak hours.

To determine the average utilization of a shopper, we need to consider the average time taken by a shopper to complete an order and the frequency of order arrivals during peak hours (4pm–8pm). With orders arriving every 9 minutes and the total time spent on picking items and checking out being 40 minutes (25 minutes for picking items + 15 minutes for checkout), we calculate the utilization rate.

An in-store shopper can handle ÷(rac{60}{40}) = 1.5 orders per hour. During peak hours, we have ÷(rac{60}{9}) = 6.67 orders arriving per hour. With 11 in-store shoppers, the total capacity is 11 × 1.5 = 16.5 orders per hour. Thus, the average utilization of a shopper is the ratio of arriving orders to the total capacity which is 6.67 orders per hour / 16.5 orders per hour = 0.404 or 40.4%.