“Monday Effect” on Performance Variations in Supply Chain Fulfillment: How Information Technology–Enabled Procurement May Help

If labor productivity varies in unknown ways over time, this could lead to unforeseen fluctuations in production or delivery rates, leading to stockouts or inventory build-up in a supply chain, while contributing to higher operating costs and to lower satisfaction levels for customers. The “Monday Effect,” that is lower productivity and higher error rates on Mondays compared with other days of the week, has been demonstrated in the finance and industrial relations literature. Using a database of 12 months of purchases from the General Services Administration (GSA) of the U.S. government (a key distributor of goods to government purchasers), we show that, indeed, performance is lower on Mondays compared with other weekdays in terms of order fulfillment and order cycle time. However, when purchasers use the GSA’s internet-based electronic market instead of using manual ordering procedures, the fulfillment gap between Mondays and other weekdays narrows considerably, demonstrating the value of information technology in smoothing distribution flows. By acknowledging the Monday Effect, distributors can thus plan for these weekly fluctuations and use information technology to improve service levels. Although there are both process-related and human-related grounds for systematic performance variations across days of the week, such a phenomenon has not caught the attention of information systems or operations management scholars. Using transaction-level data from the U.S. Government’s General Services Administration, we study three layers of effects: the Monday Effect, the Technology Effect, and the Product Effect. First, we assess whether performance varies across days of the week in supply chain fulfillment, measured by order cycle time, complete orders fulfilled, and short shipment percentage (i.e., the Monday Effect). Furthermore, we assess how information technology (IT), notably an electronic market, can mitigate such variations (i.e., the Technology Effect), and how product characteristics moderate such effects (i.e., the Product Effect). Our findings show that there indeed exist significant, systematic performance variations across days of the week, with Mondays having poorer performance than other days of the week, after controlling for workload and other factors. Further, we find that much of the performance variation can be reduced when an IT-enabled electronic market is adopted. Specifically, the performance gaps in order cycle time, complete orders fu