Documents disponibles écrits par cet auteur

Global dual sourcing / Gad Allon in Management science, Vol. 56 N° 1 (Janvier 2010) 

Public ISBD [article]  in Management science > Vol. 56 N° 1 (Janvier 2010) . - pp. 110-124 Titre : Global dual sourcing : Tailored base-surge allocation to near- and offshore production Type de document : texte imprimé Auteurs : Gad Allon, Auteur ; Jan A. Van Mieghem, Auteur Année de publication : 2010 Article en page(s) : pp. 110-124 Note générale : Management Langues : Anglais (eng) Mots-clés : Inventory  production  Stochastic  models  Applications  Probability  Stochastic  model  applications Index. décimale : 658 Organisation des entreprises. Techniques du commerce Résumé : When designing a sourcing strategy in practice, a key task is to determine the average order rates placed to each source because that affects cost and supplier management. We consider a firm that has access to a responsive nearshore source (e.g., Mexico) and a low-cost offshore source (e.g., China). The firm must determine an inventory sourcing policy to satisfy random demand over time. Unfortunately, the optimal policy is too complex to allow a direct answer to our key question. Therefore, we analyze a tailored base-surge (TBS) sourcing policy that is simple, used in practice, and captures the classic trade-off between cost and responsiveness. The TBS policy combines push and pull controls by replenishing at a constant rate from the offshore source and producing at the nearshore plant only when inventory is below a target. The constant base allocation allows the offshore facility to focus on cost efficiency, whereas the nearshore facility's quick response capability is utilized only dynamically to guarantee high service. The research goals are to (i) determine the allocation of random demand into base and surge capacity, (ii) estimate corresponding working capital requirements, and (iii) identify and value the key drivers of dual sourcing. We present performance bounds on the optimal cost and prove that economic optimization brings the system into heavy traffic. We analyze the sourcing policy that is asymptotically optimal for high-volume systems and present a simple “square-root” formula that is insightful to answer our questions and sufficiently accurate for practice, as is demonstrated with a validation study. DEWEY : 658 ISSN : 0025-1909 En ligne : http://mansci.journal.informs.org/content/56/1.toc [article] Global dual sourcing : Tailored base-surge allocation to near- and offshore production [texte imprimé] / Gad Allon, Auteur ; Jan A. Van Mieghem, Auteur . - 2010 . - pp. 110-124. Management Langues : Anglais (eng) in Management science > Vol. 56 N° 1 (Janvier 2010) . - pp. 110-124 Mots-clés : Inventory  production  Stochastic  models  Applications  Probability  Stochastic  model  applications Index. décimale : 658 Organisation des entreprises. Techniques du commerce Résumé : When designing a sourcing strategy in practice, a key task is to determine the average order rates placed to each source because that affects cost and supplier management. We consider a firm that has access to a responsive nearshore source (e.g., Mexico) and a low-cost offshore source (e.g., China). The firm must determine an inventory sourcing policy to satisfy random demand over time. Unfortunately, the optimal policy is too complex to allow a direct answer to our key question. Therefore, we analyze a tailored base-surge (TBS) sourcing policy that is simple, used in practice, and captures the classic trade-off between cost and responsiveness. The TBS policy combines push and pull controls by replenishing at a constant rate from the offshore source and producing at the nearshore plant only when inventory is below a target. The constant base allocation allows the offshore facility to focus on cost efficiency, whereas the nearshore facility's quick response capability is utilized only dynamically to guarantee high service. The research goals are to (i) determine the allocation of random demand into base and surge capacity, (ii) estimate corresponding working capital requirements, and (iii) identify and value the key drivers of dual sourcing. We present performance bounds on the optimal cost and prove that economic optimization brings the system into heavy traffic. We analyze the sourcing policy that is asymptotically optimal for high-volume systems and present a simple “square-root” formula that is insightful to answer our questions and sufficiently accurate for practice, as is demonstrated with a validation study. DEWEY : 658 ISSN : 0025-1909 En ligne : http://mansci.journal.informs.org/content/56/1.toc

Operational flexibility and financial hedging / Jiri Chod in Management science, Vol. 56 N° 6 (Juin 2010) 

Public ISBD [article]  in Management science > Vol. 56 N° 6 (Juin 2010) . - pp. 1030-1045 Titre : Operational flexibility and financial hedging : Complements or substitutes? Type de document : texte imprimé Auteurs : Jiri Chod, Auteur ; Nils Rudi, Auteur ; Jan A. Van Mieghem, Auteur Année de publication : 2010 Article en page(s) : pp. 1030-1045 Note générale : Management Langues : Anglais (eng) Mots-clés : Financial  hedging  Postponement  Flexibility  Risk  management Index. décimale : 658 Organisation des entreprises. Techniques du commerce Résumé : We consider a firm that invests in capacity under demand uncertainty and thus faces two related but distinct types of risk: mismatch between capacity and demand and profit variability. Whereas mismatch risk can be mitigated with greater operational flexibility, profit variability can be reduced through financial hedging. We show that the relationship between these two risk mitigating strategies depends on the type of flexibility: Product flexibility and financial hedging tend to be complements (substitutes)—i.e., product flexibility tends to increase (decrease) the value of financial hedging, and, vice versa, financial hedging tends to increase (decrease) the value of product flexibility—when product demands are positively (negatively) correlated. In contrast to product flexibility, postponement flexibility is a substitute to financial hedging as intuitively expected. Although our analytical results assume perfect flexibility and perfect hedging and rely on a linear approximation of the value of hedging, we validate their robustness in an extensive numerical study. DEWEY : 658 ISSN : 0025-1909 En ligne : http://mansci.journal.informs.org/content/56/6.toc [article] Operational flexibility and financial hedging : Complements or substitutes? [texte imprimé] / Jiri Chod, Auteur ; Nils Rudi, Auteur ; Jan A. Van Mieghem, Auteur . - 2010 . - pp. 1030-1045. Management Langues : Anglais (eng) in Management science > Vol. 56 N° 6 (Juin 2010) . - pp. 1030-1045 Mots-clés : Financial  hedging  Postponement  Flexibility  Risk  management Index. décimale : 658 Organisation des entreprises. Techniques du commerce Résumé : We consider a firm that invests in capacity under demand uncertainty and thus faces two related but distinct types of risk: mismatch between capacity and demand and profit variability. Whereas mismatch risk can be mitigated with greater operational flexibility, profit variability can be reduced through financial hedging. We show that the relationship between these two risk mitigating strategies depends on the type of flexibility: Product flexibility and financial hedging tend to be complements (substitutes)—i.e., product flexibility tends to increase (decrease) the value of financial hedging, and, vice versa, financial hedging tends to increase (decrease) the value of product flexibility—when product demands are positively (negatively) correlated. In contrast to product flexibility, postponement flexibility is a substitute to financial hedging as intuitively expected. Although our analytical results assume perfect flexibility and perfect hedging and rely on a linear approximation of the value of hedging, we validate their robustness in an extensive numerical study. DEWEY : 658 ISSN : 0025-1909 En ligne : http://mansci.journal.informs.org/content/56/6.toc

Optimal flexibility configurations in newsvendor networks / Achal Bassamboo in Management science, Vol. 56 N° 8 (Août 2010) 

Public ISBD [article]  in Management science > Vol. 56 N° 8 (Août 2010) . - pp. 1285-1303 Titre : Optimal flexibility configurations in newsvendor networks : Going beyond chaining and pairing Type de document : texte imprimé Auteurs : Achal Bassamboo, Auteur ; Ramandeep S. Randhawa, Auteur ; Jan A. Van Mieghem, Auteur Année de publication : 2010 Article en page(s) : pp. 1285-1303 Note générale : Management Langues : Anglais (eng) Mots-clés : Inventory  production  Stochastic  models  Programming  Linear  Applications  Queues  Networks  Flexibility  Newsvendor  networks Index. décimale : 658 Organisation des entreprises. Techniques du commerce Résumé : We study the classical problem of capacity and flexible technology selection with a newsvendor network model of resource portfolio investment. The resources differ by their level of flexibility, where “level-k flexibility” refers to the ability to process k different product types. We present an exact set-theoretic methodology to analyze newsvendor networks with multiple products and parallel resources. This simple approach is sufficiently powerful to prove that (i) flexibility exhibits decreasing returns and (ii) the optimal portfolio will invest in at most two, adjacent levels of flexibility in symmetric systems, and to characterize (iii) the optimal flexibility configuration for asymmetric systems as well. The optimal flexibility configuration can serve as a theoretical performance benchmark for other configurations suggested in the literature. For example, although chaining is not optimal in our setting, the gap is small and the inclusion of scale economies quickly favors chaining over pairing. We also demonstrate how this methodology can be applied to other settings such as product substitution and queuing systems with parameter uncertainty. DEWEY : 658 ISSN : 0025-1909 En ligne : http://mansci.journal.informs.org/content/56/8.toc [article] Optimal flexibility configurations in newsvendor networks : Going beyond chaining and pairing [texte imprimé] / Achal Bassamboo, Auteur ; Ramandeep S. Randhawa, Auteur ; Jan A. Van Mieghem, Auteur . - 2010 . - pp. 1285-1303. Management Langues : Anglais (eng) in Management science > Vol. 56 N° 8 (Août 2010) . - pp. 1285-1303 Mots-clés : Inventory  production  Stochastic  models  Programming  Linear  Applications  Queues  Networks  Flexibility  Newsvendor  networks Index. décimale : 658 Organisation des entreprises. Techniques du commerce Résumé : We study the classical problem of capacity and flexible technology selection with a newsvendor network model of resource portfolio investment. The resources differ by their level of flexibility, where “level-k flexibility” refers to the ability to process k different product types. We present an exact set-theoretic methodology to analyze newsvendor networks with multiple products and parallel resources. This simple approach is sufficiently powerful to prove that (i) flexibility exhibits decreasing returns and (ii) the optimal portfolio will invest in at most two, adjacent levels of flexibility in symmetric systems, and to characterize (iii) the optimal flexibility configuration for asymmetric systems as well. The optimal flexibility configuration can serve as a theoretical performance benchmark for other configurations suggested in the literature. For example, although chaining is not optimal in our setting, the gap is small and the inclusion of scale economies quickly favors chaining over pairing. We also demonstrate how this methodology can be applied to other settings such as product substitution and queuing systems with parameter uncertainty. DEWEY : 658 ISSN : 0025-1909 En ligne : http://mansci.journal.informs.org/content/56/8.toc