Documents disponibles écrits par cet auteur

Capacity sizing under parameter uncertainty / Achal Bassamboo in Management science, Vol. 56 N° 10 (Octobre 2010) 

Public ISBD [article]  in Management science > Vol. 56 N° 10 (Octobre 2010) . - pp. 1668-1686 Titre : Capacity sizing under parameter uncertainty : Safety staffing principles revisited Type de document : texte imprimé Auteurs : Achal Bassamboo, Auteur ; Ramandeep S. Randhawa, Auteur ; Assaf Zeevi, Auteur Année de publication : 2010 Article en page(s) : pp. 1668-1686 Note générale : Management Langues : Anglais (eng) Mots-clés : Service  systems  Capacity  sizing  Parameter  uncertainty Index. décimale : 658 Organisation des entreprises. Techniques du commerce Résumé : We study a capacity sizing problem in a service system that is modeled as a single-class queue with multiple servers and where customers may renege while waiting for service. A salient feature of the model is that the mean arrival rate of work is random (in practice this is a typical consequence of forecasting errors). The paper elucidates the impact of uncertainty on the nature of capacity prescriptions, and relates these to well established rules-of-thumb such as the square-root safety staffing principle. We establish a simple and intuitive relationship between the incoming load (measured in Erlangs) and the extent of uncertainty in arrival rates (measured via the coefficient of variation) that characterizes the extent to which uncertainty dominates stochastic variability or vice versa. In the former case it is shown that traditional square-root safety staffing logic is no longer valid, yet simple capacity prescriptions derived via a suitable newsvendor problem are surprisingly accurate. DEWEY : 658 ISSN : 0025-1909 En ligne : http://mansci.journal.informs.org/cgi/content/abstract/56/10/1668 [article] Capacity sizing under parameter uncertainty : Safety staffing principles revisited [texte imprimé] / Achal Bassamboo, Auteur ; Ramandeep S. Randhawa, Auteur ; Assaf Zeevi, Auteur . - 2010 . - pp. 1668-1686. Management Langues : Anglais (eng) in Management science > Vol. 56 N° 10 (Octobre 2010) . - pp. 1668-1686 Mots-clés : Service  systems  Capacity  sizing  Parameter  uncertainty Index. décimale : 658 Organisation des entreprises. Techniques du commerce Résumé : We study a capacity sizing problem in a service system that is modeled as a single-class queue with multiple servers and where customers may renege while waiting for service. A salient feature of the model is that the mean arrival rate of work is random (in practice this is a typical consequence of forecasting errors). The paper elucidates the impact of uncertainty on the nature of capacity prescriptions, and relates these to well established rules-of-thumb such as the square-root safety staffing principle. We establish a simple and intuitive relationship between the incoming load (measured in Erlangs) and the extent of uncertainty in arrival rates (measured via the coefficient of variation) that characterizes the extent to which uncertainty dominates stochastic variability or vice versa. In the former case it is shown that traditional square-root safety staffing logic is no longer valid, yet simple capacity prescriptions derived via a suitable newsvendor problem are surprisingly accurate. DEWEY : 658 ISSN : 0025-1909 En ligne : http://mansci.journal.informs.org/cgi/content/abstract/56/10/1668

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

The auditor's slippery slope / Carlos Corona in Management science, Vol. 56 N° 6 (Juin 2010) 

Public ISBD [article]  in Management science > Vol. 56 N° 6 (Juin 2010) . - pp. 924-937 Titre : The auditor's slippery slope : An analysis of reputational incentives Type de document : texte imprimé Auteurs : Carlos Corona, Auteur ; Ramandeep S. Randhawa, Auteur Année de publication : 2010 Article en page(s) : pp. 924-937 Note générale : Management Langues : Anglais (eng) Mots-clés : Reputation  Auditing  Game  theory  Sequential  equilibrium Index. décimale : 658 Organisation des entreprises. Techniques du commerce Résumé : Reputational concerns have commonly been perceived to have a positive effect on auditing firms' execution of their monitoring and attesting functions. This paper demonstrates that this need not always be the case by studying a two-period game of repeated interaction between a manager and an auditor under the assessment of the market for audit services. Regarding reputation as the sole motivator for the auditor, we illustrate how reputational concerns induce an auditing firm to misreport. We investigate the reasons and circumstances under which such misreporting takes place. In particular, a strategic manager can induce the audit firm down a slippery slope, wherein the managerial fraud increases as the tenure of the audit firm progresses, whereas the auditor's fraud reporting probability decreases. DEWEY : 658 ISSN : 0025-1909 En ligne : http://mansci.journal.informs.org/content/56/6.toc [article] The auditor's slippery slope : An analysis of reputational incentives [texte imprimé] / Carlos Corona, Auteur ; Ramandeep S. Randhawa, Auteur . - 2010 . - pp. 924-937. Management Langues : Anglais (eng) in Management science > Vol. 56 N° 6 (Juin 2010) . - pp. 924-937 Mots-clés : Reputation  Auditing  Game  theory  Sequential  equilibrium Index. décimale : 658 Organisation des entreprises. Techniques du commerce Résumé : Reputational concerns have commonly been perceived to have a positive effect on auditing firms' execution of their monitoring and attesting functions. This paper demonstrates that this need not always be the case by studying a two-period game of repeated interaction between a manager and an auditor under the assessment of the market for audit services. Regarding reputation as the sole motivator for the auditor, we illustrate how reputational concerns induce an auditing firm to misreport. We investigate the reasons and circumstances under which such misreporting takes place. In particular, a strategic manager can induce the audit firm down a slippery slope, wherein the managerial fraud increases as the tenure of the audit firm progresses, whereas the auditor's fraud reporting probability decreases. DEWEY : 658 ISSN : 0025-1909 En ligne : http://mansci.journal.informs.org/content/56/6.toc