@conference { ISI:000352386800106, title = {(Q, s) models for inventory policy with random component procurement lead times}, booktitle = {PROCEEDINGS OF 2013 INTERNATIONAL CONFERENCE ON INDUSTRIAL ENGINEERING AND SYSTEMS MANAGEMENT (IEEE-IESM 2013)}, year = {2013}, note = {5th International Conference on Industrial Engineering and Systems Management (IEEE IESM), Mohammadia Sch Engn, Rabat, MOROCCO, OCT 28-30, 2013}, pages = {718-726}, publisher = {IEEE; IEEE Morocco Sect; I4e2; Univ Valenciennes Hannaut Cambresis; Univ Mohammed V Agdal Rabat; CNRST; CISIT; ENIM; ESITH; GDR MACS; LAMIH CNRS; IFSTTAR; IRT RAILENIUM; TEMPO}, organization = {IEEE; IEEE Morocco Sect; I4e2; Univ Valenciennes Hannaut Cambresis; Univ Mohammed V Agdal Rabat; CNRST; CISIT; ENIM; ESITH; GDR MACS; LAMIH CNRS; IFSTTAR; IRT RAILENIUM; TEMPO}, abstract = {This paper considers inventory models of (Q, s) type with Q the order-quantity and s the order point. In general, an optimal choice of control parameters (Q and s) will depend on the characteristics of replenishment lead time and the demand process, as well as holding and shortage costs. Although many studies have treated lead time as constant, focusing only on demand variability, a number of authors have shown that a stochastic lead time is an issue that can have significant impact on inventory models and systems. This paper addresses the model when supply is assumed to have an exponential lead time distribution, and the {\textquoteleft}{\textquoteleft}customer{{\textquoteright}{\textquoteright}} itself is an exponential unreliable manufacturing plant, aiming for a constant mean production rate; thus both supply and demand have random characteristics. Under a so-called averaging principle approximation, we derive closed form expressions of the quantities of interest and illustrate their application in the optimization of the Q and s parameters.}, isbn = {978-2-9600532-4-1}, author = {Mhada, Fatima and Malhame, Roland and Pellerin, Robert and Sadr, Javad and Gharbi, Ali}, editor = {Aboutajdine, D and Skalli, A and Benchekroun, B and Artiba, A} }