scholarly journals UPAYA IMPROVEMENT PENGENDALIAN PERSEDIAAN SUKU CADANG DENGAN METODE FIXED TIME PERIOD PADA PT XYZ

2019 ◽  
Vol 3 (2) ◽  
pp. 129-140
Author(s):  
Sazli Tutur Risyahadi (Universitas IPB - Indonesia) ◽  
Hanifah Yunan Putri (Universitas IPB - Indonesia)
Keyword(s):  
Standard Deviation ◽  
Inventory Management ◽  
Fixed Time ◽  
Service Level ◽  
Spare Parts ◽  
Order Quantity ◽  
Time Intervals ◽  
Time Period ◽  
Spare Parts Inventory ◽  
Abc Analysis

Abstract  Perusahaan yang memiliki keinginan untuk memenangkan persaingan yang terus meningkat di era globalisasi, perlu terus menerus melakukan perbaikan metode pengendalian persediaan suku cadangnya. Metode existing di perusahaan memiliki beberapa kekurangan seperti belum mempertimbangkan standar deviasi demand dan service level yang dikehendaki oleh perusahaan. Tujuan kajian ini adalah melakukan perbaikan pengelolaan persediaan suku cadang dengan menerapkan model yang memiliki karakteristik pengadaan yang sesuai dengan perusahaan. Model Fixed Time Period (FTP) adalah model yang sesuai karena telah memenuhi karakteristik pengelolaan persediaan di perusahaan seperti pemesanan barang dengan interval waktu yang konstan dan demand yang berfluktuatif. Hasil menunjukkan bahwa jumlah pemesanan pada suku cadang bandsaw dengan menggunakan metode existing perusahaan di tahun 2018 selalu lebih tinggi quantity ordernya dibandingkan dengan menggunakan metode FTP. Berbeda dengan suku cadang bandsaw, suku cadang thermoc, jumlah order dengan metode FTP tidak selalu lebih rendah; bahkan metode FTP seringkali lebih tinggi atau pun sama quantity ordernya pada tahun 2018.  Kata Kunci: Analisis ABC, Metode Fixed Time Period, Manajemen Inventori The company that has the desire to winning the increasing competition in the era of globalization need to improve the method of spare parts inventory control continually. Existing approaches in companies have several disadvantages such as not considering the standard deviation of demand and service level desired by the company. The purpose of this study is to improve the management of spare parts inventories by implementing a model that have right characteristics that are in line with the company. The Fixed Time Period (FTP) model is an appropriate model because it has fulfilled the characteristic of inventory management in companies such as ordering goods with constant time intervals and fluctuating demand. The results show that the number of orders on bandsaw parts using the existing company method in 2018 always has a higher order quantity than using the FTP method. Unlike bandsaw parts, thermoc parts, the number is not still lower; even the FTP method was often higher or equal to the order quantity in 2018. Keywords: ABC Analysis, Fixed Time Period Methods, Inventory Management

scholarly journals Decreasing Total Inventory Cost by Controlling Inventory in Motorcycle Dealer

2020 ◽  
Vol 22 (2) ◽  
pp. 41-49
Author(s):  
David ◽  
Engmir ◽  
Irwan Budiman ◽  
Jusra Tampubolon
Keyword(s):  
Inventory Management ◽  
Demand Forecasting ◽  
Spare Parts ◽  
Order Quantity ◽  
Inventory Cost ◽  
Safety Stock ◽  
Safety Stocks ◽  
Forecasting Method ◽  
Total Inventory ◽  
Abc Analysis

This research was conducted at one of the motorcycle dealers in Indonesia. Besides selling motorcycles, this dealer also provides services to repair motorcycles and sells genuine motorcycle parts. Inventory management which the company carried out is still not good enough because there are still demand for spare parts from consumers that cannot be fulfilled by the company. The purpose of this study is to draw up a plan to control spare parts by paying attention to the spare parts that need to be considered, estimating the exact number of spare parts demand, knowing the smallest total inventory cost, knowing the amount of safety stock needed, and knowing when to reorder. In preparing the spare parts control, the methods used are ABC analysis, demand forecasting method, and EOQ method. The results of this study are plans to control the inventory of Tire, Rr. such as the forecasting sales of Tire, Rr. as many as 17338, economic order quantity of Tire Rr are 2158 units, the number of safety stocks of Tire, Rr. needed in 2020 are 1738 units, and the reorder point in 2020 is 8 times with the total inventory cost for Tire, Rr. in 2020 is Rp. 30,009,005.

scholarly journals LUMPY DEMAND FORECASTING USING LINEAR EXPONENTIAL SMOOTHING, ARTIFICIAL NEURAL NETWORK, AND BOOTSTRAP

2018 ◽  
Vol 10 (2) ◽  
pp. 107
Author(s):  
Sinta Rahmawidya Sulistyo ◽  
Alvian Jonathan Sutrisno
Keyword(s):  
Neural Network ◽  
Artificial Neural Network ◽  
Inventory Management ◽  
Spare Part ◽  
Service Level ◽  
Exponential Smoothing ◽  
Spare Parts ◽  
Forecasting Methods ◽  
Forecasting Method ◽  
Spare Parts Inventory

Lumpy demand represents the circumstances when a demand for an item has a large proportion of periods having zero demand. This certain situation makes the time series methods might become inappropriate due to the model’s inability to capture the demand pattern. This research aims to compare several forecasting methods for lumpy demand that is represented by the demand of spare part. Three forecasting methods are chosen; Linear Exponential Smoothing (LES), Artificial Neural Network (ANN), and Bootstrap. The Mean Absolute Scaled Error (MASE) is used to measure the forecast performance. In order to gain more understanding on the effect of the forecasting method on spare parts inventory management, inventory simulation using oil and gas company’s data is then conducted. Two inventory parameters; average inventory and service level; are used to measure the performance. The result shows that ANN is found to be the best method for spare part forecasting with MASE of 0,761. From the inventory simulation, the appropriate forecasting method on spare parts inventory management is able to reduce average inventory by 11,9% and increase service level by 10,7%. This result justifies that selecting the appropriate forecasting method is one of the ways to achieve spare part inventory management’s goal.

scholarly journals AIRCRAFT SPARE PARTS INVENTORY MANAGEMENT ANALYSIS ON AIRFRAME PRODUCT USING CONTINUOUS REVIEW METHODS

2020 ◽  
Vol 2 (1) ◽  
pp. 81-90
Author(s):  
Faikar Ridwan Harimansyah ◽  
Tukhas Shilul Imaroh
Keyword(s):  
Inventory Management ◽  
Cost Efficiency ◽  
Moving Average ◽  
Demand Forecasting ◽  
Service Level ◽  
Spare Parts ◽  
Continuous Review ◽  
Planning Methods ◽  
Abc Analysis ◽  
Single Exponential

The research  aims to find the factors that cause high inventory value, increase the value of forecasting precision, service level and cost efficiency with fishbone diagrams and proposed methods. The research sample is 9 spare parts included in classification A in the ABC analysis and maintenance list 2018. Forecasting methods use Moving Average, Single Exponential Smoothing and Syntetos-Boylan Approximation as well as Mean Square Error calculation, deterministic inventory calculation and Continuous Review Method. The results of this study are an increase in logistics costs by $ 808.71 in the inventory management proposal. An increase in service level from 95% to 99% and the error value in the calculation of the proposal becomes smaller using the proposed method. This study also found that the factor causing the high inventory value was due to inaccurate planning methods so that other comparative methods were needed that could increase the precision of demand forecasting.

ANALYSIS OF THE MANAGEMENT OF MATERIAL AND TECHNICAL ASSETS OF ENTERPRISES

2021 ◽  
Vol 116 (1) ◽  
pp. 293-299
Author(s):  
Aizhan Talgatkyzy Syrkebai
Keyword(s):  
Inventory Management ◽  
Realistic Model ◽  
Process Approach ◽  
Sustainable Competitive Advantage ◽  
Order Quantity ◽  
Specific Product ◽  
Abc Classification ◽  
Eoq Model ◽  
Demand Rate ◽  
Abc Analysis

Variability of demand for goods, depending on their availability and cost is a frequently observed phenomenon in the sphere of production and consumption. This paper discusses the possibility of using the ABC analysis for the inventory management system. This type of analysis makes it possible to apply various methods of inventory management for increasing the income and reducing the costs of particular products for manufacturers. As is known, the management process approach emphasizes the systematic study of management by defining management functions in an organization and then examining each in detail. There is a general agreement on the planning, organizing, and controlling functions. Traditional inventory management systems, such as the Lean Order Quantity (EOQ) model, are based on the assumptions of constant demand rate, constant inventory cost, and instant order. The EOQ assumption of instant order receipt means that the entire order quantity, that is, all units of the purchased lot is immediately received from the supplier. The Economic Production Quantity (EPQ) model weakens this assumption by including incremental order receipt, i.e. debit. In recent years, major advances in the sphere of management include the following elements: process approach management science decision support approach, scientific approach to human resources development, and sustainable competitive advantage. These four approaches complement one another in current practice and provide a useful framework for project management. This paper presents a realistic model of the goods production and their inventory, since ABC analysis or ABC classification is an integral part of materials management. According to this approach, the inventory is divided into three categories depending on income generation. The ABC analysis helps entrepreneurs identify the main types of products in the warehouse, prioritize the goods management based on their cost, and analyze customer demand for a specific product.

scholarly journals A Simulation-Based Model for Determining Safety Inventory at a Fixed-time Period System

2019 ◽  
Vol 8 (12) ◽  
pp. 2775-2780
Keyword(s):  
Lead Time ◽  
Fixed Time ◽  
Service Level ◽  
Microsoft Excel ◽  
Time Period ◽  
Simulation Based ◽  
Period System ◽  
Daily Forecast ◽  
Visual Basic Application ◽  
Normally Distributed

This paper develops a simulation model for determining safety inventory associated with a certain value of cycle service level in a fixed-time period system. The model takes into account actual amount of materials received from suppliers, and deviation from probability distribution of daily forecast demand. Constraints on order size are also embodied into the model. This model was constructed by using Visual Basic Application added in Microsoft Excel. After developing the model, hypotheses testing is employed to verify the model. This model allows identifying safety inventory under uncertain conditions which prohibits from the use of ordinary mathematical formula. The model was locally verified. Stochastic variables including customer demand and supplier’s lead time are assumed to be normally distributed. Independent demand items are considered and backorders are not allowed. Under specific conditions, such as distributions of demand and lead time are normally distributed, and fixed-time period system is being used. This model allows materials planner promptly identifies safety inventory associated with a certain level of cycle service level. Furthermore, planner can perceive the affects of changing input parameters on the amount of safety inventory required. There were very few researches focus on variations of demand and lead time at the same time. In reality, this case usually happens, thus the firms have been facing highly variations form both supplier and customers. Therefore, this paper intends to close this gap by simulating these factors and taken into account for determining safety inventory.

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