Same-day or next-day? Transparent time-dependent shipment pricing for e-fulfillment
Uta Mohring, Melvin Drent, Ivo Adan, Willem van Jaarsveld
TL;DR
The paper addresses balancing same-day and next-day e-fulfillment demand through transparent, time-dependent shipment pricing. It develops a discrete-time periodic Markov-chain model, and a problem-domain transform that maps policies to cumulative express-demand profiles, enabling tractable analysis. Key results show the optimal policy has a cutoff point and monotonically increasing express-fees, with a simple two-level fee structure achieving near-optimal performance and practical interpretability. Numerical experiments demonstrate substantial profit gains from time-dependent pricing, validating the approach as a transparent mechanism to align demand with fulfillment capacity while preserving customer fairness. The work provides actionable guidelines and a path toward polynomial-time optimization for complex time-dependent pricing in deadline-driven fulfillment settings.
Abstract
We develop a parsimonious model of an e-commerce fulfillment center that offers time-dependent shipment options and corresponding fees to utility-maximizing customers arriving according to a Poisson process. For any such policy, we provide an exact steady-state analysis using the underlying periodic Markov chain to characterize system performance. Because shipment fees shape both the volume and timing of same-day demand, direct optimization over the price domain is analytically intractable. To enable structural and computational insights, we introduce a transformation that maps each shipment-fee policy to its induced cumulative demand profile. This reformulation reveals that the optimal policy features a cutoff time and monotonically increasing fees, and it yields a supermodular profit function that can be optimized in polynomial time. We also propose a simple two-level time-dependent fee structure that is intuitive for customers and achieves near-optimal performance. Numerical experiments show that introducing a cutoff time substantially improves profits under static fees, and that using time-dependent fees produces further significant gains. Overall, transparent time-dependent shipment policies help firms align same-day demand with fulfillment capacity while maintaining transparency and fairness for customers.
