Traditional versus fast fashion supply chains in the apparel industry: An agent-based simulation approach

Backs S, Jahnke H, Lüpke L, Stücken M, Stummer C. Traditional versus fast fashion supply chains in the apparel industry: An agent-based simulation approach. Annals of Operations Research. 2021;305(1-2):487-512

Improved Approximation Algorithms for the Min-Max Selecting Items Problem

We give a simple deterministic $O(\log K / \log\log K)$ approximation algorithm for the Min-Max Selecting Items problem, where $K$ is the number of scenarios. While our main goal is simplicity, this result also improves over the previous best approximation ratio of $O(\log K)$ due to Kasperski, Kurpisz, and Zieli\'nski (Information Processing Letters (2013)). Despite using the method of pessimistic estimators, the algorithm has a polynomial runtime also in the RAM model of computation. We also show that the LP formulation for this problem by Kasperski and Zieli\'nski (Annals of Operations Research (2009)), which is the basis for the previous work and ours, has an integrality gap of at least $\Omega(\log K / \log\log K)$

A Fibonacci sequence for linear structures with two types of components

We investigate binary voting systems with two types of voters and a hierarchy among the members in each type, so that members in one class have more influence or importance than members in the other class. The purpose of this paper is to count, up to isomorphism, the number of these voting systems for an arbitrary number of voters. We obtain a closed formula for the number of these systems, this formula follows a Fibonacci sequence with a smooth polynomial variation on the number of voters.Comment: All the results contained in this file are included in a paper submitted to Annals of Operations Research in October, 2008 on ocasion of the Conference on Applied Mathematical Programming and Modelling, that held in Bratislava in May, 200

An analytic derivation of the efficient frontier in biobjective cash management and its implications for policies

[EN] Cash managers who optimize returns and risk rely on biobjective optimization models to select the best policies according to their risk preferences. In the related portfolio selection problem, Merton (J Financ Quant Anal 7(4):1851¿1872, 1972) provided the first analytical derivation of the efficient frontier with all non-dominated return and risk combinations. This first proposal was later extended to account for three or more criteria by other authors. However, the cash management literature needs an analytical derivation of the efficient frontier to help cash managers evaluate the implications of selecting policies and risk measures. In this paper, we provide three analytic derivations of the efficient frontier determining a closed-form solution for the expected returns and risk relationship using three different risk measures. We study its main properties and its theoretical implications for policies. Using the variance of returns as a risk measure imposes limitations due to invertibility reasons.Open Access funding provided thanks to the CRUE-CSIC agreement with Springer Nature.Salas-Molina, F.; Pla Santamaría, D.; Rodriguez-Aguilar, JA. (2023). An analytic derivation of the efficient frontier in biobjective cash management and its implications for policies. Annals of Operations Research (Online). 328(2):1523-1536. https://doi.org/10.1007/s10479-023-05433-z152315363282Baumol, W. J. (1952). The transactions demand for cash: An inventory theoretic approach. The Quarterly Journal of Economics, 66(4), 545–556.Constantinides, G. M., & Richard, S. F. (1978). Existence of optimal simple policies for discounted-cost inventory and cash management in continuous time. Operations Research, 26(4), 620–636.da Costa Moraes, M. B., Nagano, M. S., Sobreiro, V. A., et al. (2015). Stochastic cash flow management models: A literature review since the 1980s. In P. Guarnieri (Ed.), Decision Models in Engineering and Management (pp. 11–28). Berlin: Springer.Markowitz, H. (1952). The Portfolio selection. Journal of Finance, 7(1), 77–91.Merton, R. C. (1972). An analytic derivation of the efficient portfolio frontier. Journal of Financial and Quantitative Analysis, 7(4), 1851–1872.Miller, M. H., & Orr, D. (1966). A model of the demand for money by firms. The Quarterly Journal of Economics, 80(3), 413–435.Qi, Y. (2020). Parametrically computing efficient frontiers of portfolio selection and reporting and utilizing the piecewise-segment structure. Journal of the Operational Research Society, 71(10), 1675–1690.Qi, Y. (2022). Classifying the minimum-variance surface of multiple-objective portfolio selection for capital asset pricing models. Annals of Operations Research, 311(2), 1203–1227.Qi, Y., & Li, X. (2020). On imposing ESG constraints of portfolio selection for sustainable investment and comparing the efficient frontiers in the weight space. SAGE Open, 10(4), 1–17.Qi, Y., & Steuer, R. E. (2020). On the analytical derivation of efficient sets in quad-and-higher criterion portfolio selection. Annals of Operations Research, 293(2), 521–538.Qi, Y., Steuer, R. E., & Wimmer, M. (2017). An analytical derivation of the efficient surface in portfolio selection with three criteria. Annals of Operations Research, 251(1–2), 161–177.Salas-Molina, F. (2019). Selecting the best risk measure in multiobjective cash management. International Transactions in Operational Research, 26(3), 929–945.Salas-Molina, F. (2020). Risk-sensitive control of cash management systems. Operational Research, 20(2), 1159–1176.Salas-Molina, F., Pla-Santamaria, D., & Rodríguez-Aguilar, J. A. (2018). Empowering cash managers through compromise programming. In H. Masri, B. Perez-Gladish, & C. Zopounidis (Eds.), Financial decision aid using multiple criteria (pp. 149–173). Berlin: Springer.Salas-Molina, F., Pla-Santamaria, D., & Rodriguez-Aguilar, J. A. (2018). A multi-objective approach to the cash management problem. Annals of Operations Research, 267(1), 515–529.Salas-Molina, F., Rodriguez-Aguilar, J. A., & Díaz-García, P. (2018). Selecting cash management models from a multiobjective perspective. Annals of Operations Research, 261(1), 275–288.Salas-Molina, F., Rodriguez-Aguilar, J. A., Pla-Santamaria, D., & García-Bernabeu, A. (2021). On the formal foundations of cash management systems. Operational Research, 21(2), 1081–1095.Salas-Molina, F., Rodríguez-Aguilar, J. A., & Guillen, M. (2023). A multidimensional review of the cash management problem. Financial Innovation, 9(67), 1–35.Savage, L. J. (1951). The theory of statistical decision. Journal of the American Statistical Association, 46(253), 55–67.Schroeder, P., & Kacem, I. (2019). Optimal cash management with uncertain, interrelated and bounded demands. Computers & Industrial Engineering, 133, 195–206.Schroeder, P., & Kacem, I. (2020). Competitive difference analysis of the cash management problem with uncertain demands. European Journal of Operational Research, 283(3), 1183–1192

A New Method for Solving Fuzzy Linear Programs with Trapezoidal Fuzzy Numbers

Ganesan and Veeramani [Fuzzy linear programs with trapezoidal fuzzy numbers, Annals of Operations Research 143 (2006) 305-315.] proposed a new method for solving a special type of fuzzy linear programming problems. In this paper a new method, named as Mehar's method, is proposed for solving the same type of fuzzy linear programming problems and it is shown that it is easy to apply the Mehar's method as compared to the existing method for solving the same type of fuzzy linear programming problems

Analysis of Multiserver Retrial Queueing System: A Martingale Approach and an Algorithm of Solution

The paper studies a multiserver retrial queueing system with $m$ servers. Arrival process is a point process with strictly stationary and ergodic increments. A customer arriving to the system occupies one of the free servers. If upon arrival all servers are busy, then the customer goes to the secondary queue, orbit, and after some random time retries more and more to occupy a server. A service time of each customer is exponentially distributed random variable with parameter $\mu_1$. A time between retrials is exponentially distributed with parameter $\mu_2$ for each customer. Using a martingale approach the paper provides an analysis of this system. The paper establishes the stability condition and studies a behavior of the limiting queue-length distributions as $\mu_2$ increases to infinity. As $\mu_2\to\infty$, the paper also proves the convergence of appropriate queue-length distributions to those of the associated `usual' multiserver queueing system without retrials. An algorithm for numerical solution of the equations, associated with the limiting queue-length distribution of retrial systems, is provided.Comment: To appear in "Annals of Operations Research" 141 (2006) 19-52. Replacement corrects a small number of misprint

Wait-and-see strategies in polling models

We consider a general polling model with $N$ stations. The stations are served exhaustively and in cyclic order. Once a station queue falls empty, the server does not immediately switch to the next station. Rather, it waits at the station for the possible arrival of new work ("wait-and-see") and, in the case of this happening, it restarts service in an exhaustive fashion. The total time the server waits idly is set to be a fixed, deterministic parameter for each station. Switchover times and service times are allowed to follow some general distribution, respectively. In some cases, which can be characterised, this strategy yields strictly lower average queueing delay than for the exhaustive strategy, which corresponds to setting the "wait-and-see credit" equal to zero for all stations. This extends results of Pek\"oz (Probability in the Engineering and Informational Sciences 13 (1999)) and of Boxma et al. (Annals of Operations Research 112 (2002)). Furthermore, we give a lower bound for the delay for {\it all} strategies that allow the server to wait at the stations even though no work is present.Comment: 24p, submitte

The Incremental Cooperative Design of Preventive Healthcare Networks

This document is the Accepted Manuscript version of the following article: Soheil Davari, 'The incremental cooperative design of preventive healthcare networks', Annals of Operations Research, first published online 27 June 2017. Under embargo. Embargo end date: 27 June 2018. The final publication is available at Springer via http://dx.doi.org/10.1007/s10479-017-2569-1.In the Preventive Healthcare Network Design Problem (PHNDP), one seeks to locate facilities in a way that the uptake of services is maximised given certain constraints such as congestion considerations. We introduce the incremental and cooperative version of the problem, IC-PHNDP for short, in which facilities are added incrementally to the network (one at a time), contributing to the service levels. We first develop a general non-linear model of this problem and then present a method to make it linear. As the problem is of a combinatorial nature, an efficient Variable Neighbourhood Search (VNS) algorithm is proposed to solve it. In order to gain insight into the problem, the computational studies were performed with randomly generated instances of different settings. Results clearly show that VNS performs well in solving IC-PHNDP with errors not more than 1.54%.Peer reviewe