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Control variance amplification in linear time invariant decentralized supply chains / Hua Xu in Industrial & engineering chemistry research, Vol. 49 N° 18 (Septembre 2010) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 49 N° 18 (Septembre 2010) . - pp. 8644–8656 Titre : Control variance amplification in linear time invariant decentralized supply chains : a minimum variance control perspective Type de document : texte imprimé Auteurs : Hua Xu, Auteur ; Gang Rong, Auteur ; Yiping Feng, Auteur Année de publication : 2010 Article en page(s) : pp. 8644–8656 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Supply  chains Résumé : This paper addresses demand uncertainty and its propagation in supply chains. The supply chain is considered as a linear time invariant (LTI) system driven by stochastic customer demand. Under general ARMA demand patterns and arbitrary lead times, a unified and structured framework based on the classical minimum variance control theory is proposed for decentralized supply chain management (SCM). Optimal forecasting, the traditional order-up-to policy and the generalized order-up-to policy are directly derived according to the minimum variance criterion. Given these strategies, stochastic properties of the supply chain are studied using LTI system theory in both the time and the frequency domain. Findings from previous literature are reinterpreted from a control-theory-oriented perspective, and new characteristics of the generalized order-up-to policy are deduced and analyzed. On the basis of the statistical analysis, an optimization model is constructed to minimize the variable operation costs which are related to the parameters of the SCM strategies. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100167u [article] Control variance amplification in linear time invariant decentralized supply chains : a minimum variance control perspective [texte imprimé] / Hua Xu, Auteur ; Gang Rong, Auteur ; Yiping Feng, Auteur . - 2010 . - pp. 8644–8656. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 18 (Septembre 2010) . - pp. 8644–8656 Mots-clés : Supply  chains Résumé : This paper addresses demand uncertainty and its propagation in supply chains. The supply chain is considered as a linear time invariant (LTI) system driven by stochastic customer demand. Under general ARMA demand patterns and arbitrary lead times, a unified and structured framework based on the classical minimum variance control theory is proposed for decentralized supply chain management (SCM). Optimal forecasting, the traditional order-up-to policy and the generalized order-up-to policy are directly derived according to the minimum variance criterion. Given these strategies, stochastic properties of the supply chain are studied using LTI system theory in both the time and the frequency domain. Findings from previous literature are reinterpreted from a control-theory-oriented perspective, and new characteristics of the generalized order-up-to policy are deduced and analyzed. On the basis of the statistical analysis, an optimization model is constructed to minimize the variable operation costs which are related to the parameters of the SCM strategies. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100167u

A minimum variance control theory perspective on supply chain lead time uncertainty / Hua Xu in Industrial & engineering chemistry research, Vol. 51 N° 27 (Juillet 2012) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 51 N° 27 (Juillet 2012) . - pp. 9275-9286 Titre : A minimum variance control theory perspective on supply chain lead time uncertainty Type de document : texte imprimé Auteurs : Hua Xu, Auteur ; Rong, Gang, Auteur Année de publication : 2012 Article en page(s) : pp. 9275-9286 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Uncertainty Résumé : This paper addresses the lead time uncertainty problem in supply chain systems. In our previous paper [Xu et al. Ind. Eng. Chem. Res.2010,49,8644], we have investigated the impact of demand uncertainty on supply chains. Here we adopt a two-echelon supply chain model, which is basically the same as that used in the research of demand uncertainty. But the fixed lead time setting is replaced by a Markovian lead time model. Since the lead time varies with time, the dynamic characteristics of the supply chain model are different from that used in the demand uncertainty research. We make a comparison analysis of these differences from the view of dynamic systems. On the basis of the above analysis, we adopt two fundamental lemmas of the minimum variance control theory as the foundation for replenishment rules design and analysis. Then we derive formulas of the Order-up-to policy and the generalized Order-up-to policy with time-varying lead time. Moreover, we offer the variant forms of the above strategies when the lead time information is incomplete. Given the strategies, we analyze the influence of lead time information on the order and inventory variances and corresponding costs. This work, together with our previous paper on demand uncertainty, may provide a coherent control theory based perspective on these two different types of uncertainties in a supply chain. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26132264 [article] A minimum variance control theory perspective on supply chain lead time uncertainty [texte imprimé] / Hua Xu, Auteur ; Rong, Gang, Auteur . - 2012 . - pp. 9275-9286. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 27 (Juillet 2012) . - pp. 9275-9286 Mots-clés : Uncertainty Résumé : This paper addresses the lead time uncertainty problem in supply chain systems. In our previous paper [Xu et al. Ind. Eng. Chem. Res.2010,49,8644], we have investigated the impact of demand uncertainty on supply chains. Here we adopt a two-echelon supply chain model, which is basically the same as that used in the research of demand uncertainty. But the fixed lead time setting is replaced by a Markovian lead time model. Since the lead time varies with time, the dynamic characteristics of the supply chain model are different from that used in the demand uncertainty research. We make a comparison analysis of these differences from the view of dynamic systems. On the basis of the above analysis, we adopt two fundamental lemmas of the minimum variance control theory as the foundation for replenishment rules design and analysis. Then we derive formulas of the Order-up-to policy and the generalized Order-up-to policy with time-varying lead time. Moreover, we offer the variant forms of the above strategies when the lead time information is incomplete. Given the strategies, we analyze the influence of lead time information on the order and inventory variances and corresponding costs. This work, together with our previous paper on demand uncertainty, may provide a coherent control theory based perspective on these two different types of uncertainties in a supply chain. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26132264