An approximate model for base-stock-controlled assembly systems

Avşar, Zeynep Müge
This study is on continuously reviewed base-stock-con trolled assembly systems with Poisson demand arrivals and exponential single-server facilities used for manufacturing and assembly operations. A partially aggregated but exact queueing model is developed and approximated assuming that the state-dependent transition rates arising as a result of the partial aggregation are constant. It is shown that the steady-state probability distribution of this approximate model is a product-form distribution for the simplest case with two components making up an assembly. Based on this analytical observation, similar product-form distributions are proposed for more complex assembly systems. Comparisons with simulation and matrix-geometric solutions show that the proposed product-form steady-state distributions accurately approximate relevant performance measures with a considerable advantage in terms of the required computational effort. A greedy heuristic is devised to use approximate steady-state probabilities for optimizing design parameters like base-stock levels.


Analysis of a deterministic demand production/inventory system under nonstationary supply uncertainty
Gullu, R; Onol, E; Erkip, N (Informa UK Limited, 1997-08-01)
In this article we investigate a periodic review inventory model under deterministic dynamic demand and supply unavailability. In a given period, supply is either available or completely unavailable with given probabilities. Supply unavailability probabilities are nonstationary over time. We show the optimality of an order-up-to level policy, and obtain a newsboy-like formula that determines the optimal order-up-to levels. Our formula would provide guidence as to the appropriate amount of inventory to stock...
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Hekimoğlu, Özge; Serpil, Canan; Department of Industrial Engineering (2007)
In this study, results of a comparison on benchmark test problems are presented to investigate the performance of Primavera V.4.1 with its two resource allocation priority rules and MS Project 2003. Resource allocation capabilities of the packages are measured in terms of deviation from the upper bound of the minimum makespan. Resource constrained project scheduling problem instances are taken from PSPLIB which are generated under a factorial design from ProGen. Statistical tests are applied to the results ...
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Sevinç, Selim; Meral, Fatma Sedef; Department of Industrial Engineering (2008)
In this study, a Lagrangean heuristic based on Lagrangean relaxation and subgradient optimization is proposed for the two-stage modular capacitated facility location problem. The objective is to minimize the cost of locating and operating plants and warehouses, plus the cost of transporting goods at both echelons to satisfy the demand of customers. The difference of our study from the two-stage capacitated facility location problem is the existence of multiple capacity levels as a candidate for each plant i...
A closed-form approach for identification of dynamical contact parameters in spindle-holder-tool assemblies
Özşahin, Orkun; Özgüven, Hasan Nevzat (Elsevier BV, 2009-01-01)
Accurate identification of contact dynamics is very crucial in predicting the dynamic behavior and chatter stability of spindle-tool assemblies in machining centers. it is well known that the stability lobe diagrams used for predicting regenerative chatter vibrations can be obtained from the tool point frequency response function (FRF) of the system. As previously shown by the authors, contact dynamics at the spindle-holder and holder-tool interfaces as well as the dynamics of bearings affect the tool point...
Finding highly preferred points for multi-objective integer programs
LOKMAN, BANU; Köksalan, Mustafa Murat (Informa UK Limited, 2014-01-01)
This article develops exact algorithms to generate all non-dominated points in a specified region of the criteria space in Multi-Objective Integer Programs (MOIPs). Typically, there are too many non-dominated points in large MOIPs and it is not practical to generate them all. Therefore, the problem of generating non-dominated points in the preferred region of the decision-maker is addressed. To define the preferred region, the non-dominated set is approximated using a hyper-surface. A procedure is developed...
Citation Formats
Z. M. Avşar and U. RODOPLU, “An approximate model for base-stock-controlled assembly systems,” IIE TRANSACTIONS, pp. 260–274, 2009, Accessed: 00, 2020. [Online]. Available: