Increasing efficiency of on-line shopping by optimizing the staff schedule

Abstract

COOP Drive is an on-line shopping system recently started by COOP Liguria. Customers place their orders on-line, which are then processed by employees and collected at the time chosen by the customer. The problem proposed by COOP consists of two main parts: i) optimizing the staff schedule in COOP Drive ii) understanding if and to what extent such a schedule could be improved if orders were placed in advance. Providing a good schedule is very important for employees to reach an adequate level of satisfaction. According to the proposed problem from the on-line food shopping service, our aim was to make optimal staff scheduling such that each employee has `constant' working hours, i.e. that they work the same number of hours each working day. We introduce three different complementary models as approaches for the solution. The fi rst model is based on scheduling approach, which we solved for a simplifi ed scenario and is aimed to answer the first part of the problem. For the second question, we adopted two different approaches: an agent-based model that aims to understand the number of employees needed to process the order history and a worker placement model, that is developed to predict the number of employees required every hour to process the orders. These two models suggest that no signi ficant reduction of employees can be obtained by placing the orders in advance, however, signi ficant bene fit is achieved in terms of homogeneity of the schedule.