Optimising safety stock placement and lead time in an assembly supply chain using bi-objective MAX–MIN ant system

2013 ◽  
Vol 145 (1) ◽  
pp. 18-28 ◽  
Author(s):  
Luis A. Moncayo-Martínez ◽  
David Z. Zhang
Keyword(s):  
Supply Chain ◽  
Lead Time ◽  
Ant System ◽  
Safety Stock

A novel approach to safety stock management in an integrated supply chain with controllable lead time and ordering cost reduction using present value

2020 ◽  
Vol 54 (5) ◽  
pp. 1327-1346 ◽  
Author(s):  
S. Tharani ◽  
R. Uthayakumar
Keyword(s):  
Supply Chain ◽  
Cost Reduction ◽  
Lead Time ◽  
Cumulative Distribution ◽  
Stock Management ◽  
Present Value ◽  
Safety Stock ◽  
Novel Approach ◽  
Cost Reductions ◽  
Ordering Cost Reduction

This paper presents a novel approach to safety stock management and investigates the impact of lead time reduction within an integrated vendor–buyer supply chain framework using present value where lead time and ordering cost reductions act dependently. In particular, the cost of the safety stock is determined by adopting a logistic approximation to the standard normal cumulative distribution. The service level is formulated in relation to the dimension of the single shipment, to the average demand of the buyer and to the number of admissible stockouts. We first discuss the case where the lead time and ordering cost reductions with linear function, and then consider the logarithmic functional relationship. Numerical examples including the sensitivity analysis with some managerial insights of system parameters is provided to validate the results of the supply chain models. The main contribution of this paper is introducing various types of ordering cost reduction in Braglia et al. (Appl. Stoc. Mod. Bus. Ind. 32 (2016) 99–112) by handling a new approach.

Supply chain management and market responsiveness: a simulation study

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Abdulqadir Rahomee Ahmed Aljanabi ◽  
Karzan Mahdi Ghafour
Keyword(s):  
Supply Chain ◽  
Lead Time ◽  
Supply And Demand ◽  
Service Level ◽  
Distribution Centers ◽  
Safety Stock ◽  
Content Type ◽  
Product Availability ◽  
Market Responsiveness ◽  
Number Of Customers

Purpose This study aims to provide a practical solution to the relationship between supply chain (SC) integration and market responsiveness (MR). A method is proposed to integrate SC and MR parameters, namely, product supply and demand in the context of low-value commodities (e.g. cement). Design/methodology/approach Simulation and forecasting approaches are adopted to develop a potential procedure for addressing demand during lead time. To establish inventory measurements (safety stock and reorder level) and increase MR and the satisfaction of customer’s needs, this study considers a downstream SC including manufacturers, depots and central distribution centers that satisfies an unbounded number of customers, which, in turn, transport the cement from the industrialist. Findings The demand during lead time is shown to follow a gamma distribution, a rare probability distribution that has not been considered in previous studies. Moreover, inventory measurements, such as the safety stock, depending on the safety factor under a certain service level (SL), which enables the SC to handle different responsiveness levels in accordance with customer requests. In addition, the quantities of the safety stock and reorder point represent an optimal value at each position to avoid over- or understocking. The role of SC characteristics in MR has largely been ignored in existing research. Originality/value This study applies SC flexibility analyzes to overcome the obstacles of analytical methods, especially when the production process involves probabilistic variables such as product availability and demand. The use of an efficient method for analyzing the forecasting results is an unprecedented idea that is proven efficacious in investigating non-dominated solutions. This approach provides near-optimal solutions to the trade-off between different levels of demand and the SC responsiveness (SLs) with minimal experimentation times.

THE EFFECT OF LEAD-TIME ON THE SUPPLY CHAIN: THE MEAN VERSUS THE VARIANCE

2011 ◽  
Vol 10 (01) ◽  
pp. 175-185 ◽  
Author(s):  
XIN JAMES HE ◽  
XIAOBO XU ◽  
JACK C. HAYYA
Keyword(s):  
Supply Chain ◽  
Lead Time ◽  
Inventory Systems ◽  
Time Variability ◽  
Inventory Cost ◽  
Safety Stock ◽  
Stochastic Inventory ◽  
Q Model ◽  
Total Inventory ◽  
The Mean

In a study on stochastic inventory systems, Chopra et al. (Decision Sciences35(1) (2004) 1–24) argue that decreasing lead time is the right lever if they want to cut inventories, not reducing lead time variability. According to Chopra et al., reducing the mean lead time, μ, is more important than reducing the lead time variance, σ2, to reduce total inventory cost via a reduced safety stock. This paper is a criticism of Chopra et al., where the optimal z was derived based upon a predetermined Q, instead of solving the optimal z and Q simultaneously in a (z, Q) inventory system. We argue that such an approach is inappropriate because the two decision variables, z and Q, are in general interdependent, and, moreover, reducing reorder point (safety stock), z, does not necessarily decrease the total inventory cost. We demonstrate by means of a truncated lead time (z, Q) model that it is lead time variability, not mean lead time, that affects the inventory policy and total supply chain cost.

scholarly journals Three-Echelon Inventory Model with Permissible Delay in Payments under Controllable Lead Time and Backorder Consideration

2014 ◽  
Vol 2014 ◽  
pp. 1-16 ◽  
Author(s):  
M. F. Yang ◽  
Wei-Chung Tseng
Keyword(s):  
Supply Chain ◽  
Lead Time ◽  
Critical Issue ◽  
Solution Procedure ◽  
Inventory Model ◽  
Permissible Delay In Payments ◽  
Inventory Policy ◽  
Controllable Lead Time ◽  
Key Factor ◽  
Delay In Payments

This paper proposes a three-echelon inventory model with permissible delay in payments under controllable lead time and backorder consideration to find out the suitable inventory policy to enhance profit of the supply chain. In today’s highly competitive market, the supply chain management has become a critical issue in both practice and academic and supply chain members have to cooperate with each other to bring more benefits. In addition, the inventory policy is a key factor to influence the performance of the supply chain. Therefore, in this paper, we develop a three-echelon inventory model with permissible delay in payments under controllable lead time and backorder consideration. Furthermore, the purpose of this paper is to maximize the joint expect total profit on inventory model and attempt to discuss the inventory policy under different conditions. Finally, with a numerical example provided here to illustrate the solution procedure, we may discover that decision-makers can control lead time and payment time to enhance the performance of the supply chain.

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