scholarly journals Multi-Criteria Inventory Optimisation of University of Ibadan, Ibadan, Nigeria’s Bakery Using Goal Programming Approach and Flour as the Major Raw-Material

2021 ◽  
Vol 9 (12) ◽  
pp. 650-660
Author(s):  
*Bolarinwa, Mojisola A. ◽  
Fajebe, Fisayo E.
Keyword(s):  
Goal Programming ◽  
Lead Time ◽  
Raw Materials ◽  
Service Level ◽  
Storage Space ◽  
Time Duration ◽  
Inventory Cost ◽  
Turnover Ratio ◽  
Total Inventory ◽  
University Of Ibadan

Asides inventory cost, which is being used as the only inventory performance measure at the University of Ibadan bakery, a number of other criteria, such as inventory cost, service level, inventory turnover and delivery lead time which influence the performance of an inventory system have surfaced over the years. Hence, there is the need to examine all these criteria-objectives altogether. Therefore, this research was centred towards optimising the inventory system of University of Ibadan bakery, putting multiple criteria into consideration. Data on 17 raw materials: their costs, suppliers, usage rate, lead time, storage space and available capital were collected by means of interviews, past records and observations. The weighted goal program algorithm was adopted to find the best compromise between fulfilling the four objectives by minimising the sum of the deviation from the target values of the goals. Subsequently, Lingo 17.0 and Tora 1.0 optimisation software packages were used to solve and compare the model generated, while putting into consideration storage space constraint and budgeted capital. The developed model from the goal programming algorithm exhibited four goals (combined into one objective function). Same solutions were obtained from Lingo 17.0 and Tora 1.0. While Lingo 17.0 gave a  uniform service level of 100% , a  turnover ratio greater than 1(>1) for all the materials at a negligible increase (of  < 0.0001%) in total inventory cost of the raw materials and available lead time duration of zero days (< 24 hours) for each material, Tora 1.0  gave a  uniform service level of 100% , a  turnover ratio greater than 1 (> 1) for all the materials at a negligible increase (of  < 0.0001%) in total inventory cost of the raw materials and available lead time duration of zero days (< 24 hours) for each material. Implementation of the developed model will eliminate unnecessary waiting time between production, thereby ensuring effective and efficient utilisation of raw materials in production which will lead to reduced cost of holding inventory, elimination of unnecessary overall cost and wastages, and also improvement of the productivity and profit on the long run.

scholarly journals DETERMINATION OF INVENTORY PERIODIC REVIEW POLICY (R, s, S) USING POWER APPROXIMATION METHOD FOR MINIMIZE TOTAL INVENTORY COST IN PT. OPQ

2019 ◽  
Vol 3 (01) ◽  
pp. 47-52
Author(s):  
Ratnawia ◽  
Rio Aurachman ◽  
Saskia Puspa Kenaka
Keyword(s):  
Manufacturing Industry ◽  
Raw Materials ◽  
Service Level ◽  
Raw Material ◽  
Periodic Review ◽  
Inventory Cost ◽  
Automotive Manufacturing ◽  
Power Approximation ◽  
Total Inventory

OPQ is a company engaged in the automotive manufacturing industry. The company produces bolts for the safety area, it is related to the lower body of the four-wheeled vehicle. PT. OPQ was established in 2014 and today has already been the supplier for several major automotive companies in Indonesia. The demand of PT OPQ that must be fulfilled is increasing as the amount of consumer is increasing too. Due to the high demand, so the raw material stockout occurs. This make the company's service level is below the standard.   This study involved 48 sku of material raw materials that have normal distributed demand. Inventory policy applied in this research is periodic review (R, s, S) with the aim to minimize total cost of inventory and improve service level of company.   The result of this research was found to decrease total inventory cost by 15% with the value of existing inventory cost Rp1.100.879.479,- to Rp 936.061.349,- . In addition, service level at PT. OPQ has increased with the value of existing conditions 85% to 99%.   Keywords—Raw Material, Periodic Review, Probabilistic, Service Level, Stock out

scholarly journals Analysis Of Stock Control Of Raw Materials Of Dzohir Noodles In Bengkulu

2022 ◽  
Vol 3 (1) ◽  
Author(s):  
Monika Ahmelia ◽  
Herlin Herlin ◽  
Abdul Rahman
Keyword(s):  
Wheat Flour ◽  
Lead Time ◽  
Raw Materials ◽  
Raw Material ◽  
Inventory Cost ◽  
Safety Stock ◽  
Stock Control ◽  
Inventory Costs ◽  
Total Inventory ◽  
Research Period

This study aims to analyze the stock inventory control of Mie Dzohir's raw materials in Bengkulu. The analytical method used is Economic Order Quantity (EOQ), Reorder Point (ROP), Total Inventory Cost (TIC) and Safety Stock (SS). The results showed that to meet the raw material needs of 91,375 kg during the research period, from January 2020 to December 2020 (12 months), the number of economical purchases/EOQ of wheat flour raw materials that had to be made by the Mie Dzohir factory in Bengkulu was as much as 5,372 kg for each order with a purchase frequency of 17 times for a period from January 2020 to December 2020. Reorders or reorder points (ROP) can also be determined, namely reordering should be done when 345 kg of inventory is in warehouse, with a lead time of 1 days so as not to hamper the company's production process. The total inventory cost (TIC) can also be determined, namely the total cost of raw material inventory of Rp. 3.572.188, - therefore, it can save on inventory costs of Rp. 1.051.697,- .Safety stock (SS) of 95 kg which must be in the warehouse, this is intended therefore, there is no shortage of wheat flour raw materials if there is a delay in the delivery of raw materials.

DETERMINATION OF INVENTORY PERIODIC REVIEW POLICY (R, s, S) USING POWER APPROXIMATION METHOD FOR MINIMIZE TOTAL INVENTORY COST IN PT. OPQ

2019 ◽  
Vol 3 (01) ◽  
Author(s):  
Ratna Wia ◽  
Rio Aurachman ◽  
Saskia Puspa Kenaka
Keyword(s):  
Manufacturing Industry ◽  
Raw Materials ◽  
Service Level ◽  
Raw Material ◽  
Periodic Review ◽  
Inventory Cost ◽  
Automotive Manufacturing ◽  
Power Approximation ◽  
Total Inventory

PT. OPQ is a company engaged in the automotive manufacturing industry. The company produces bolts for the safety area, it is related to the lower body of the four-wheeled vehicle. PT. OPQ was established in 2014 and today has already been the supplier for several major automotive companies in Indonesia. The demand of PT OPQ that must be fulfilled is increasing as the amount of consumer is increasing too. Due to the high demand, so the raw material stockout occurs. This make the company's service level is below the standard. This study involved 48 sku of material raw materials that have normal distributed demand. Inventory policy applied in this research is periodic review (R, s, S) with the aim to minimize total cost of inventory and improve service level of company. The result of this research was found to decrease total inventory cost by 15% with the value of existing inventory cost Rp1.100.879.479,- to Rp 936.061.349,- . In addition, service level at PT. OPQ has increased with the value of existing conditions 85% to 99%.

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 PENGENDALIAN PERSEDIAAN BAHAN BAKU DALAM PROSES PRODUKSI DENGAN MENGGUNAKAN METODE ECONOMIC ORDER QUANTITY (EOQ)

2019 ◽  
Vol 1 (2) ◽  
pp. 415-423
Author(s):  
Elia Rahayu R ◽  
Nor Norisanti ◽  
Acep Samsudin
Keyword(s):  
Raw Materials ◽  
Raw Material ◽  
Economic Order Quantity ◽  
Economic Order ◽  
Order Quantity ◽  
Analysis Method ◽  
Inventory Cost ◽  
Total Inventory ◽  
The Difference ◽  
Quantitative Descriptive

The purpose of this study is to control the supply of raw materials using the Economic Order Quantity (EOQ) method in Tahu Nugraha Jaya Sukabumi UKM. The data analysis method used is quantitative descriptive to describe and describe the data to be examined and then processed using EOQ. This study uses the EOQ method to determine the total inventory cost. The data needed in this study are the number of purchases of raw materials, the amount of use of raw materials, storage costs, and ordering costs. The results of this study indicate that by applying the EOQ method can further optimize the supply of raw materials by minimizing raw materials with increased inventory. With the application of the Economic Order Quantity (EOQ) method it shows more efficient than conventional methods of the company. Conclusions, seen from the difference in the TIC of the two methods, the more efficient method is the Economic Order Quantity (EOQ) method that is equal to 244,392.94 while the calculation used by the company is 374,325. so that it can be obtained that there is a difference between the Company TIC and the EIC method TIC. Keywords: Raw Material Inventory, Production Process

scholarly journals Analysis and Design of Information Systems for Control of Raw Materials in UD. YRS Alumunium Work Using EOQ Method

Tech-E ◽  
2020 ◽  
Vol 4 (1) ◽  
pp. 30
Author(s):  
Assaji Assaji ◽  
Rudy Arijanto
Keyword(s):  
Information Systems ◽  
Raw Materials ◽  
Order Quantity ◽  
Sequence Diagrams ◽  
Inventory Cost ◽  
Safety Stock ◽  
Analysis And Design ◽  
Total Inventory ◽  
Manual Recording ◽  
Class Diagrams

In the current era of globalization, information technology and information systems are developing very fast. YRS Alumunium Work is a furniture company that manufactures cupboards, stove racks, sinks, and especially for storage of household items. The problems currently being faced by businesses, among others; (a) recording still using stationery and books or still using manual recording methods, (b) ineffective stock checking, (c) sudden out of stock, to solve the problem it is proposed to make a system using the web that can be integrated into stock by a calculation method. With UML scenario depiction (activity diagrams, usecase diagrams, class diagrams, sequence diagrams). To check the inventory of goods easily done effectively, know the minimum amount of stock, and must place an order again using the EOQ (Economic Order Quantity) method. By using the eoq method, it takes into account that for bolts to get an economical amount of inventory as much as 522.01 with a safety stock of 21 will place an order again when the stock becomes 50 and the total inventory cost is 110 458.4418.

scholarly journals Inventory model for deteriorating items with negative exponential demand, probabilistic deterioration and fuzzy lead time under partial back logging

2020 ◽  
Vol 30 (3) ◽  
Author(s):  
Nabendu Sen ◽  
Sumit Saha
Keyword(s):  
Inventory Management ◽  
Lead Time ◽  
Probability Distributions ◽  
Optimal Strategies ◽  
Inventory Model ◽  
Deteriorating Items ◽  
Optimal Time ◽  
Inventory Cost ◽  
Total Inventory ◽  
Negative Exponential

The effect of lead time plays an important role in inventory management. It is also important to study the optimal strategies when the lead time is not precisely known to the decision makers. The aim of this paper is to examine the inventory model for deteriorating items with fuzzy lead time, negative exponential demand, and partially backlogged shortages. This model is unique in its nature due to probabilistic deterioration along with fuzzy lead time. The fuzzy lead time is assumed to be triangular, parabolic, trapezoidal numbers and the graded mean integration representation method is used for the defuzzification purpose. Moreover, three different types of probability distributions, namely uniform, triangular and Beta are used for rate of deterioration to find optimal time and associated total inventory cost. The developed model is validated numerically and values of optimal time and total inventory cost are given in tabular form, corresponding to different probability distribution and fuzzy lead-time. The sensitivity analysis is performed on variation of key parameters to observe its effect on the developed model. Graphical representations are also given in support of derived optimal inventory cost vs. time.

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 Implementasi Algoritma Wagner-Within pada Manajemen Inventori di PT X

2018 ◽  
Vol 3 (1) ◽  
Author(s):  
Puspandam Katias ◽  
Achmad Affandi
Keyword(s):  
Production System ◽  
Manufacturing Industry ◽  
Raw Materials ◽  
Raw Material ◽  
Efficient Production ◽  
Manufacturing Companies ◽  
Inventory Cost ◽  
Qualitative Descriptive ◽  
Total Inventory ◽  
Supporting Material

The increasing competition in the manufacturing industry caused increasing inconsumer demand of the quality and quantity of a good product. Therefore, manufacturing companies must have reliable services, policies and product qualities to satisfy its customers. So it needs to be supported by efficient production system and inventory system. To able to create an efficient production system then need a good raw material inventory planning. This research aims to compere how efficiently in planning raw materials inventory between Wagner-Within Algorithm with the actual concept that applied to PT X, Sidoarjo. The methodology of this research is qualitative descriptive research. The findings this research is engaged in packaging (woven bag and jumbo bag) with main raw materials such as plastic ore and supporting material in inner, thread, additive, and pigment. Based on the result of the analysis is known that the actual concept of the company gives the total inventory cost IDR 3.151.000.000 with the frequency of ordering 12 times while WagnerWithin Algorithm method provides a more efficient total inventory cost of Rp. 2.685.821.101 with8 times the frequency of ordering and can savings of 14.8% of total raw material inventory cost.

scholarly journals PENDAPATAN USAHA DAN PERSEDIAAN BAHAN BAKU INDUSTRI BAWANG GORENG (Studi Kasus Industri Bawang Goreng “Uda Saprudin”)

2020 ◽  
Vol 13 (2) ◽  
pp. 8-17
Author(s):  
Herlena Bidi Astuti ◽  
Yesmawati Y ◽  
Linda Harta ◽  
Reswita R
Keyword(s):  
Lead Time ◽  
Raw Materials ◽  
Raw Material ◽  
Added Value ◽  
Operating Income ◽  
Inventory Costs ◽  
The Past ◽  
Total Inventory ◽  
C Value

Processing shallots into fried onions is one of the agro-industry businesses with the main raw material of shallots. The fried onion home industry is a downstreaming of agricultural commodities by providing added value from the raw materials of shallots, in the process of production competition the industry must conduct management that will produce raw materials to ensure obtaining products. The purpose of this study was to determine the operating income of fried onions and determine the management of raw materials in the "Uda Saprudin" fried onion industry in Bengkulu City. The method used in this study is the calculation of income, R / C ratio, and management of raw materials using EOQ, Safety Stock, Reorder Points, lead time and total inventory costs. This research is a case study conducted in February 2019 with the data used is the data of the past year (2018). From the research results obtained R / C value of 1.36 and the management of raw material requirements recognized EOQ value: 6.546 Kg, Reorder Point value: 6.329 Kg / Month, lead time: 0.5 months and Total inventory costs: Rp. 163,676,047 per year.

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