Switchgear Component Commonality Design Method Considering Delivery Lead-Time and Inventory Level

2007 ◽  
Author(s):  
Haruki Kariya ◽  
Kazuhiro Izui ◽  
Shinji Nishiwaki ◽  
Masataka Yoshimura ◽  
Yoshiya Ogihara ◽  
...  
Keyword(s):  
Production System ◽  
Design Problem ◽  
Lead Time ◽  
Design Method ◽  
Inventory Level ◽  
Lead Times ◽  
Scale Production ◽  
Objective Functions ◽  
Inventory Cost ◽  
Production Problem

Product families are groups of related products that take advantage of part commonalities at various levels to streamline delivery of maximal product variety with minimal cost impact and as short as possible lead-times. This paper proposes a new integrated product design method for build-to-order production system based products, using the product family concept, which considers product performance, delivery lead-time and inventory cost. The development and discussion of this method uses a switchgear design problem as a concrete and practical design case. A build-to-order production system has been applied to switchgear manufacturing due to its small-scale production and a variety of customer requirements. However, if the risk of maintaining unsold inventory can be decreased, manufacturers can justify holding an amount of versatile inventory. In this paper, inventory production system is applied to the switchgear production problem to shorten the delivery lead-time. The switchgear design and production problem is formulated using three objective functions, which are subassembly procurement lead-time, inventory cost and area occupied by various switchgear configurations. Moreover, to assist inventory cost evaluations, a simulation procedure for the inventory system is proposed. The proposed method is used to obtain a Pareto optimal solution set of the three objective functions. Finally, an example switchgear design problem is solved to illustrate that optimal use of component commonalities across different modules can significantly reduce inventory costs, while also shortening product delivery lead-times.

scholarly journals Increasing Productivity by Reducing Manufacturing Lead Time through Value Stream Mapping

2012 ◽  
pp. 225-229
Author(s):  
Renu Yadav ◽  
Ashish Shastri ◽  
Mithlesh Rathore
Keyword(s):  
Lead Time ◽  
Value Added ◽  
Value Stream Mapping ◽  
Mapping Technique ◽  
Inventory Level ◽  
Lead Times ◽  
Business World ◽  
Value Stream ◽  
Current State ◽  
Future State

To survive in today’s competitive business world, companies require small lead times, low costs and high customer service levels. As such, companies pay more effort to reduce their manufacturing lead times. Value stream mapping (VSM) technique has been used on a broad scale in big companies such as Toyota and Boeing. This paper considers the implementation of value stream mapping technique in manufacturing helical springs by railway spring manufacturing company. It focuses on product family, current state map improvements and the future state map. The aim is to identify waste in the form of non value added activities & processes and then removing them to improve the performance of the company. Current state map is prepared to describe the existing position and various problem areas.. Future state map is prepared to show the proposed improvement action plans. The achievements of value stream implementation are reduction in lead time, cycle time and inventory level. It was found that even a small company can make significant improvements by adopting VSM technology. It was concluded that if we adopt the VSM technique the company could reduce the manufacturing lead time from 36.86 days to 34.06 days.

Comparative multi criteria analysis and dependent optimisation through integrated supply chain

2014 ◽  
Vol 63 (8) ◽  
pp. 1046-1069 ◽  
Author(s):  
Sanjay Sharma ◽  
Akshat Sisodia
Keyword(s):  
Supply Chain ◽  
Lead Time ◽  
Service Level ◽  
Inventory Level ◽  
Inventory Policies ◽  
Inventory Cost ◽  
Content Type ◽  
Customer Service Level ◽  
Integrated Supply Chain ◽  
Different Levels

Purpose – The purpose of this paper is to compare various inventory policies and their effect on various performance metrics at different levels of a multi stage supply chain. Later the model is integrated to include optimization of entire supply chain through implementation of collaborative supply chain model. Design/methodology/approach – Alternative inventory policies have been developed at different echelons and a comparison reflecting the usability on various factors such as inventory level, inventory cost and service level is presented so as to support the decision-making process. Various inventory policies such as economic order quantity, periodic ordering (T, M) and stock to demand have been considered. Along with the basic assumptions; lead time, demand variability, variability in demand during lead time, stock out costs have also been included to make the model more applicable to practical situations. Findings – After the selection of most appropriate inventory policy at each level through a decision matrix, the total cost of operating such a supply chain is calculated along with other parameters such as service level and inventory turns. The approach is of aggregating the optimized value at each echelon referred to as aggregated supply chain in the paper. Then the concept of integrated supply chain is introduced which optimizes the supply chain as a whole, rather than aggregating local optima. The comparison is made between the two approaches that prove the integrated supply chain's superiority. Furthermore, dependent optimization is run as it is not practically possible for each echelon to optimize at the same time. Originality/value – Each echelon is allowed to optimize at a time and other echelons assume corresponding values. This final comparative multi criterion analysis is based on the three factors, i.e. inventory cost, customer service level and inventory turnover with different weights assigned to each factor at different levels of a supply chain. Finally a consolidation of results is made to reflect the overall preference which proves that an integrated supply chain best serves all the parameters combined together.

scholarly journals Pengembangan Model Vendor Managed Inventory dengan Banyak Retailer yang Mempertimbangkan Ketidakpastian Lead Times

2018 ◽  
Vol 7 (1) ◽  
pp. 41
Author(s):  
Carles Sitompul ◽  
Paulina Ariningsih ◽  
Ida Bagus Deva Narswara Santosa
Keyword(s):  
Inventory Management ◽  
Lead Time ◽  
Mathematical Formulation ◽  
Lead Times ◽  
Approximation Model ◽  
Vendor Managed Inventory ◽  
Inventory Cost ◽  
Inventory Management System ◽  
Total Inventory ◽  
The Cost

<p><em>An inventory management system in supply chains called Vendor Managed Inventory (VMI) is very promising due to the cost efficiency resulted from implementing such system. This research aims to develop a vendor managed inventory for multiple retailers. The model also takes into account lead time uncertainties from vendor to its retailers. A mathematical formulation for VMI with multiple retailers is first developed using deterministic lead times.  Subsequently, lead times uncertainties are then taken into account where modes lead times are broken into two components: modes and delays, each with their respective probabilities. In turn, an approximation model is used to solve the problem because the complexity aroused from the model is difficult to solve using analytical methods. It is shown that the proposed approximation method is able to solve VMI problem with multiple retailers and uncertain lead times.  Furthermore, the total inventory cost is significantly reduced when compared to the usual economic order quantity method because stockouts are less frequent. </em></p>

3108 Component Commonality Design Method for Switchgears Considering Inventory Level and Delivery Lead-time

2007 ◽  
Vol 2007.4 (0) ◽  
pp. 189-190
Author(s):  
Haruki KARIYA ◽  
Kazuhiro IZUI ◽  
Shinji NISHIWAKI ◽  
Masataka YOSHIMURA ◽  
Shuichi HAYASHI ◽  
...  
Keyword(s):  
Lead Time ◽  
Design Method ◽  
Inventory Level ◽  
Component Commonality

scholarly journals Inventory Level Improvement in Pharmacy Company Using Probabilistic EOQ Model and Two Echelon Inventory: A Case Study

2020 ◽  
Vol 13 (3) ◽  
pp. 229-242
Author(s):  
Desy Anisya Farmaciawaty ◽  
◽  
Mursyid Hasan Basri ◽  
Akbar Adhi Utama ◽  
Fransisca Budyanto Widjaja ◽  
...  
Keyword(s):  
Inventory Management ◽  
Lead Time ◽  
Inventory Level ◽  
Setup Cost ◽  
Inventory Cost ◽  
Decentralized System ◽  
Class A ◽  
Eoq Model ◽  
Holding Cost

Abstract. This research is aimed to maintain the inventory level in a two-echelon pharmacy company. The company is a pharmacy company that has 16 branches that operate in Bandung and the surrounding area. The company has a problem with its high inventory cost. To solve the problem, the authors compare two methods that suit the company condition, i.e., the decentralized system using probabilistic EOQ model and the centralization system using the multi-echelon inventory technique. We analyzed sales data and on-hand inventory data acquired from the company information system to perform the study. We limit the scope to the class A items only. We also assume the lead time, setup cost, and holding cost used in this study with the company's owner's consent. To conclude, using the decentralized system, the company will save 31% of their inventory cost, while using the centralization system with the multi-echelon technique, the company will be able to save 61% of their inventory cost. We recommend the company to refer to its competitive strategy before deciding which model it would be implemented. Keywords: Centralization, Decentralization, Probabilistic Economic Order Quantity (EOQ), Multi-Echelon Inventory, Pharmaceutical Inventory Management

Modeling of an Inventory System with Variable Demands and Lead Times using a Fuzzy Approach

2016 ◽  
pp. 133-151
Author(s):  
Vijay Kumar ◽  
Pravin Kumar
Keyword(s):  
Customer Service ◽  
Lead Time ◽  
Service Level ◽  
Research Topic ◽  
Lead Times ◽  
Inventory Cost ◽  
Safety Stock ◽  
Customer Service Level ◽  
Optimum Order ◽  
Total Inventory

Inventory modeling has always been an innovative research topic for the researchers. It is concerned with minimization of the total inventory cost and maximization of the service level with minimum inventory. In the real world, the demand is always variable; and also the lead time of supply of an item cannot be always fixed due to some unavoidable circumstances. This chapter is focused on an inventory model with shortages where demand quantity and lead time are considered as variable and represented by triangular fuzzy numbers. An expression for optimum order size, reorder point, safety stock and fuzzy total safety stock cost is developed for a fixed customer service level. This model may help the manager to minimize the inventory cost with a maximum service level under the environment of uncertainty and vague information.

scholarly journals Exploiting Random Lead Times for Significant Inventory Cost Savings

2021 ◽  
Author(s):  
Alexander L. Stolyar ◽  
Qiong Wang
Keyword(s):  
Inventory Management ◽  
Lead Time ◽  
Cost Savings ◽  
Distributed Networks ◽  
Lead Times ◽  
Supply Chain Performance ◽  
Inventory Cost ◽  
Inventory Costs ◽  
Simulation Results ◽  
Base Stock Policies

Taking Advantage of the Lead Time Randomness in Supply Chains Randomness in lead times is a major—and increasingly important—issue of inventory management, as a variety of risk factors motivate companies to diversify their supply sources and rely on distributed networks of suppliers. In “Exploiting Random Lead Times for Significant Inventory Cost Savings,” A. Stolyar and Q. Wang show that, surprisingly, instead of being a damaging factor to supply chain performance, randomness may be harnessed for potentially very substantial reductions of inventory costs. Specifically, the theoretical analysis and simulation results in the paper demonstrate that, under certain conditions, appropriately designed novel policies can significantly outperform the conventional base stock policies.

scholarly journals Decision of Lead-Time Compression and Stable Operation of Supply Chain

Complexity ◽  
2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Songtao Zhang ◽  
Shuangshuang Li ◽  
Siqi Zhang ◽  
Min Zhang
Keyword(s):  
Supply Chain ◽  
Robust Control ◽  
Control Strategy ◽  
Lead Time ◽  
Cost Optimization ◽  
Inventory Level ◽  
Lead Times ◽  
Stable Operation ◽  
Optimization Strategy ◽  
Time Compression

A cost optimization strategy and a robust control strategy were studied to realize the low-cost robust operation of the supply chain with lead times. Firstly, for the multiple production lead times which existed in the supply chain, a corresponding inventory state model and a supply chain cost model were constructed based on the Takagi-Sugeno fuzzy control system. Then, by considering the actual inventory level, the lead-time compression cost, and the stock-out cost, a cost optimization strategy was proposed. Furthermore, a fuzzy robust control strategy was proposed to realize the flexible switching among the models. Finally, the simulation results show that the total cost of the supply chain could be reduced effectively by the cost optimization strategy, and the stable operation of the supply chain could be realized by the proposed fuzzy robust control strategy.

Application of Improved Safety Inventory Quantity in Building Construction

2011 ◽  
Vol 99-100 ◽  
pp. 250-253
Author(s):  
Xiang Chen ◽  
Xue Feng Zhou ◽  
Wei Hou
Keyword(s):  
Lead Time ◽  
Collaborative Planning ◽  
Building Construction ◽  
Inventory Level ◽  
Inventory Cost ◽  
Material Supply ◽  
Good Relation

Safety inventory quantity computation based on Collaborative Planning Forecasting & Replenishment (CPFR) can avoid uncertainty of material supply in building construction, which can also coordinate relationship between supplier and construction side to reduce inventory cost and to ensure the progress of construction. The paper analyzed systematically on relationship between lead time and safety inventory. Combining with application of CPFR and based on establishing good relation between material supplier and construction contractors, safety inventory level was reduced with management of lead time. Supply of material supplier was also coordinated to reduce uncertainty of inventory quantity. Construction application example based on improved safety inventory quantity method also proves the feasibility of the proposed method.

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