Publication Type
Journal Article
Version
acceptedVersion
Publication Date
7-2026
Abstract
In this paper, we study the assortment optimization problem under the mixed-logit customer choice model. While assortment optimization has been a central topic in revenue management for decades, the mixed-logit model is widely regarded as one of the most general and flexible frameworks for modeling and predicting customer purchasing behavior. The assortment optimization problem is known to be NP-hard to be approximated to any constant factor, even in the unconstrained case. To address this challenge, we first explore the submodularity properties of a simplified version of the objective function to derive novel semi-constant factor approximation solutions for assortment problems under various constraint settings, including unconstrained, cardinality-constrained, (multi-)knapsack-constrained, and matroid-constrained scenarios. Our approximation schemes are applicable to both finite-mixture and infinite-mixture settings. Furthermore, to solve the assortment optimization problem optimally in practice, we propose a novel approach that leverages outer approximation techniques to approximate certain convex and supermodular components of the objective function. This results in novel cutting-plane and branch-and-cut procedures that efficiently solve the problem. Extensive experiments demonstrate that our approaches consistently outperform existing methods in terms of both solution quality and computational efficiency.
Keywords
Capacitated assortment optimization, Mixed logit model, Approximation scheme, Outer-approximation, Cutting plane, Branch-and-Cut
Discipline
Numerical Analysis and Scientific Computing | Operations Research, Systems Engineering and Industrial Engineering
Research Areas
Intelligent Systems and Optimization
Publication
European Journal of Operational Research
Volume
332
Issue
1
First Page
257
Last Page
275
ISSN
0377-2217
Identifier
10.1016/j.ejor.2025.11.004
Publisher
Elsevier
Embargo Period
3-27-2026
Citation
PHAM, Hoang Giang and MAI, Tien.
Constrained assortment optimization under the mixed-logit model. (2026). European Journal of Operational Research. 332, (1), 257-275.
Available at: https://ink.library.smu.edu.sg/sis_research/11058
Creative Commons License

This work is licensed under a Creative Commons Attribution-NonCommercial-No Derivative Works 4.0 International License.
Additional URL
https://doi.org/10.1016/j.ejor.2025.11.004
Included in
Numerical Analysis and Scientific Computing Commons, Operations Research, Systems Engineering and Industrial Engineering Commons