scholarly journals Optimization for Inventory Level of Spare Parts Considering System Availability

2014 ◽  
Vol 31 (2) ◽  
pp. 1-13 ◽  
Author(s):  
Heung-Seob Kim ◽  
Pansoo Kim
Keyword(s):  
Spare Parts ◽  
Inventory Level ◽  
System Availability

MODEL OF SYSTEM AVAILABILITY CAUSED BY SPARE PARTS INVENTORY LEVEL

2006 ◽  
Vol 13 (01) ◽  
pp. 37-45
Author(s):  
ANNA JODEJKO
Keyword(s):  
Critical Level ◽  
Spare Parts ◽  
Technical System ◽  
Inventory Level ◽  
System Availability ◽  
Set Size ◽  
Spare Parts Inventory ◽  
Estimation System

There are many models and methods that enable estimation system availability when set size of spares inventory is accessible. Correct determining of standby of a system should consider also the lack of inventory delivery precision effect. The paper presents model of inventory critical level of spare element impact on technical system availability when delivery moment is assumed to be a random. Presented approach allows to calculate the probability of the system down time and probability of its availability-based consequences.

scholarly journals Pengendalian Persediaan Untuk Mengurangi Biaya Total Persediaan Dengan Pendekatan Metode Periodic Review (R,s,S) Power Approximation Pada Suku Cadang Consumable (Studi Kasus : Job Pertamina Talisman Jambi Merang)

2017 ◽  
Vol 4 (1) ◽  
pp. 8
Author(s):  
Adhi Putra Mahardika ◽  
Muhammad Nashir Ardiansyah ◽  
Efrata Denny S. Yunus
Keyword(s):  
Service Level ◽  
Spare Parts ◽  
Gas Production ◽  
Inventory Level ◽  
Periodic Review ◽  
Inventory Cost ◽  
Turbine Engine ◽  
Total Cost ◽  
Gas Processing ◽  
Power Approximation

Spare parts is one of the production support components which plays an important role for the survival<br />of gas production in the gas processing facility owned by SKN JOB Pertamina Talisman Jambi Merang. The<br />high inventory level increased the high inventory cost for the industry which get the benefit from the efficiency<br />of processes and resources. This research involved consumable spare parts for Solar Turbine engine as much<br />as 25 SKUs with demand character patterned lumpy demand and Poisson distribution. The implementation<br />of policies using Periodic Review (R, s, S) with Power Approximation approach in the inventory system<br />capable to generate a lower total cost inventory by pressing the backorder volume, the booking volume and the<br />inventory levels in a balanced manner. Calculation of Periodic Review (R, s, S) with Power Approximation<br />approach resulted inventory parameter which was able to press the total cost of inventory at 8.54% lower and<br />increase the service level by 1.11%.

Materials and Spare Parts Management for Gas Pipelines

2004 ◽  
Author(s):  
Reinaldo Andrade
Keyword(s):  
End Users ◽  
Spare Parts ◽  
Inventory Level ◽  
Material Management ◽  
Standard Interval ◽  
Stock Investment ◽  
Spare Parts Management ◽  
Proposed Model ◽  
City Gates ◽  
Demand Profile

The challenge for materials and spare parts management is to keep an economical inventory level and assure reliability to end-users. Another challenge is to have end users committed to the management model and procedures. The usual models call for re-order points and statistics analyses that do not fit the normal demand profile of pipelines. The proposed model works in committees by equipments or installations (as compressor stations, city-gates, etc.). The committee defines the necessary level of reliability for each material or component, estimated demand, normalized specification, etc. The Stock Base model supplies the statistical support for defining the quantity to maintain during the leading time plus a standard interval between semiannual or annual analyses. The model combines the most important concepts practiced by material management: Pareto’s Principle to indicate the economical standpoint to be considered in the analyses, statistical concepts to indicate the level of reliability required (accepted interval between two consecutive non-stock situation), traditional methods of material management (as the replenishment stock level) and the most important: the end users recommendation. The main results of this model are: low inventory levels, non-repetition of items in stock, different treatment for classes A, B and C items, combination of economical and operational importance resulting in reliability and stock investment reduction.

A Risk Based Methodology for Spare Parts Inventory Optimisation

2008 ◽  
Author(s):  
Ujjwal R. Bharadwaj ◽  
Vadim V. Silberschmidt ◽  
John B. Wintle ◽  
Julian B. Speck
Keyword(s):  
Inventory Management ◽  
Optimal Level ◽  
Risk Profile ◽  
Spare Parts ◽  
Inventory Level ◽  
Machine Availability ◽  
Inventory Optimization ◽  
Spare Parts Inventory ◽  
Current Context ◽  
Capital Intensive

Spare parts inventories assist maintenance staff to keep equipment in operating condition. Thus the inventory level of spares has a direct bearing on machine availability, a factor that is increasingly important in capital-intensive industries. This paper presents a risk based approach for spare parts inventory optimization. At the outset, the paper highlights the unique features of maintenance inventories, such as spare parts inventories, compared to other inventories such as work-in-progress or finished product inventories. After a brief mention of the principles on which many of the current inventory management models are based and their limitations, the paper presents a risk-based methodology to spares inventory management. ‘Risk’ in the current context is the risk in monetary terms that arises when a component (spare) is not available on demand. It is the expected value of loss, i.e., the product of the likelihood of unavailability of the spare from the inventory and an estimate of the consequence(s) of that unavailability. Given a budgetary constraint and the risk profile of a number of spares, the model gives an optimal inventory of spares. By basing the inventory on the risk profile of spares, the model includes factors that are not normally considered in various other models. The ultimate aim of the methodology is to have an optimal level of spares inventory such that machine availability, to the extent it is dependent on the level of spares inventory, is maximized subject to constraints. The methodology is expected to benefit both, operational and financial managers.

scholarly journals The Determination Of Optimal Inventory Using Markov Chain

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Novie Novie ◽  
Haryadi Sarjono
Keyword(s):  
Markov Chain ◽  
Inventory Control ◽  
Spare Parts ◽  
Inventory Level ◽  
Research Results ◽  
Markov Chain Method ◽  
Crucial Problem ◽  
Optimal Inventory Level ◽  
A Company

The complication of inventory is a crucial problem for the company because inventory is one of the valuable assets for the company. The existence of inventory control is needed so the inventory levels that exist within the company is not in very large (optimal) therefore the costs incurred by the company can be suppressed as minimum as possible. PT NM is a company engaged in spare parts, especially branded cars in West Jakarta. The level of inventories of goods owned by  these  companies is high because The company did not want to experience stock out of stock but on one side the stock is large enough so the costs incurred  by  companies  such as storage costs of goods becomes even greater. In order to control inventory levels, this study uses a Markov Chain method that can identify optimal inventory level and the expectation of profits earned per month by making estimates of the future demand a previous demand. From the research results shows expectation of profit of each state starting from state 2 to state 10 is Rp 13.146,98921; Rp 12.246,94064; Rp 11.346,61466; Rp 10.444,64569; Rp 9.534,074035; Rp 8.584,408534; Rp 7.484,413248; Rp 5.913,288143; Rp 3.211,609986,-. While the profit expectations that earned by the company per month is Rp 694.233,333, and the optimal inventory level is 50.

A Combined Maintenance Strategy Considering Spares, Buffer, and Quality

2021 ◽  
pp. 1748006X2097281
Author(s):  
Shuyuan Gan ◽  
Bolun Wang ◽  
Zhifang Song
Keyword(s):  
Product Quality ◽  
Model Simulation ◽  
Optimal Solution ◽  
Spare Parts ◽  
Inventory Level ◽  
Maintenance Policy ◽  
Cost Rate ◽  
Qualification Rate ◽  
Maintenance Model ◽  
The Mathematical Model

This paper studies an innovative maintenance model for an upstream machine in a common production system. Multiple system-wise features are integrated in the model, including maintenance, spare parts, buffer inventory, and product quality. The objective is to minimize the system expected cost rate by determining the optimal inspection interval, preventive maintenance threshold, corrective maintenance threshold, reorder level of spare parts, maximum stock level of spare parts, and maximum inventory level of the buffer. In this maintenance model, both the hazard rate and the product qualification rate can trigger maintenance activities. The well-known proportional hazard model (PHM) is adopted to describe the state of the upstream machine. The effect of machine state on product quality is explicitly characterized. Due to the complexity of the mathematical model, simulation and a genetic algorithm are employed to determine the optimal solution. A case study of bearings is presented to demonstrate the performance of the proposed maintenance policy. The results show that this policy is practical and can reduce system cost significantly.

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