Vol. 5, No. 6, June 2024
E-ISSN: 2723-6692
P-ISSN: 2723-6595
http://jiss.publikasiindonesia.id/
Journal of Indonesian Social Sciences, Vol. 5, No. 6, June 2024 1318
Analysis of Raw Material Inventory Control with A Tabular
Approach and Formula Approach Economic Order Quantity
(EOQ) to Optimize The Cost of Soybean Raw Material Inventory
At The Rizqy Putra Fried Tofu Factory
Winarti Shofariah, Faldy Herdian
Universitas Teknologi Digital, Bandung, Indonesia
Email: winarti10120698@digitechuniversity.ac.id, faldyherdian@digitechuniversity.ac.id
Correspondence: winarti10120698@digitechuniversity.ac.id
*
KEYWORDS
ABSTRACT
Raw Material Inventory
Control; Formula Approach;
Economic Order Quantity
(EOQ)
Inventory management is a crucial aspect in the operations of the
manufacturing industry, including in fried tofu factories such as the Rizqy
Putra Fried Tofu Factory. The main raw material, namely soybeans, must
be managed efficiently to ensure smooth production and minimize the
costs incurred. This research aims to determine the inventory control of
soybean raw materials applied by Rizqy Putra Fried Tofu Factory, the total
inventory cost, and the optimal quantity of soybean raw material orders.
This research is quantitative research with a comparative descriptive
analysis. The data processed are the inventory purchase and usage reports
of soybean raw materials at Rizqy Putra Fried Tofu Factory in 2023. The
data analysis method used in this research includes two approaches: the
tabular approach and the formula approach with the calculation technique
of Economic Order Quantity (EOQ). Based on the results of the research,
the inventory control method applied by Rizqy Putra Fried Tofu Factory is
the traditional or conventional method, where the total inventory cost of
soybean raw materials is Rp. 18,720,000 with details of storage costs
amounting to Rp. 18,000,000 and ordering costs of Rp. 720,000 per year,
and an ordering frequency of 48 times with an average order quantity of
5,875 kg. Meanwhile, according to the calculation of the formula approach
EOQ, the optimal order quantity is 2,880 kg, with an ordering frequency of
24 times and the total inventory cost incurred is Rp. 734,387. The
conclusion of this research indicates that based on the calculation of the
EOQ formula approach, the total inventory cost of soybean raw materials
is more optimal compared to the conventional method applied by Rizqy
Putra Fried Tofu Factory.
Attribution-ShareAlike 4.0 International (CC BY-SA 4.0)
1. Introduction
A company is an organization formed by a person or group of people or entities with the aim of
producing and distributing goods or services to meet human economic needs. Every company has
various goals, including obtaining profits, maintaining a smooth production process, and achieving
various other goals (Turnip, 2017). The achievement of these goals is complex and influenced by
various factors, such as the smoothness of the production process. One of the key factors in
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manufacturing companies is the procurement and control of raw material inventory to ensure the
smooth production process which is often referred to as raw material inventory (Anista &
Widiyastuti, 2016; Haryadi & Bramasto, 2023a, 2023b).
Inventory is a material or item that is stored for use in achieving a specific purpose, such as in
the process of assembly production, resale, or for parts of a piece of equipment or machinery.
Inventory can be in the form of raw materials, auxiliary materials, work-in-progress goods, finished
goods or spare parts. Herjanto, (2017). Meanwhile, according to Assauri in Arista and Fajrin, (2016)
Inventory refers to assets consisting of goods owned by the company with the intention of being sold
during a normal business period, or inventory of goods that are still in progress or finished processes,
or inventory of raw materials that are waiting to be used in the production process. According to J.
Heizer et al., (2015) states that inventory is determining the balance between inventory investment
and customer service. Inventory goals will never achieve a low-cost strategy without good inventory
management (Akhmad & SE, 2018; Muksin, 2023).
Raw material inventory is unprocessed raw materials provided by the company for further use
in the company's production process. Raw materials are very important in manufacturing companies.
Limited or oversupply of raw materials can be a problem for the company. Shortage of raw materials
can hamper company operations, especially during production, while excess supply of raw materials
can cause excessive inventory costs and the value of raw materials will decrease over time (Julyanthry
et al., 2020).
Rizqy Putra Fried Tofu Factory is a manufacturing company engaged in the fried tofu making
industry. The company is located on Jl. Ciraden Canal Kp. Bojong Cinta Karya (Alam Sanggar Indah)
Tanjungwangi Village, Cihampelas District, West Bandung, West Java. This company has the main raw
material, namely soybeans. One important factor in the company is the inventory of raw materials as
the main source of production that must continue to be done to meet consumers (Sulistyowati &
Huda, 2021).
In its activities the company implements a continuous or continuous production process, in
which supervision in the production process is carried out thoroughly. This emphasizes the
importance of the company to carry out management functions well, especially in control, so that
company goals can be achieved. The inventory of raw materials carried out by the Rizqy Putra Fried
Tofu Factory has not been optimal, because in its activities the company purchases soybean raw
material inventory continuously without estimating production needs. In addition, there is
sometimes a shortage of soybean raw materials, caused by delays in delivery. The delay in the delivery
of soybean raw materials resulted in the hampering of fried tofu production which affected the profits
obtained by the company.
Policies on raw material inventory control applied by companies in making purchases based on
experience or observation in warehouses without estimating production needs, often experience
problems. The problem that often occurs is the scarcity and increase in soybean prices . Soybeans are
the main raw material in making fried tofu, price increases and supply scarcity can disrupt smooth
production. In addition, there is a risk of excess stock of raw materials that can lead to an increase in
inventory costs. This is because soybean storage is optimal in just a span of one to two months,
exceeding this limit can result in quality degradation or even spoilage.
Therefore, the company must control the inventory of soybean raw materials. Controlling raw
material inventory is very important to minimize the risk of raw material shortages. To determine
the optimal order quantity of soybeans, companies need to implement inventory control methods
such as the order economy model. It aims to minimize the total cost of raw material inventory while
maximizing profits.
The Economic Order Quantity (EOQ) method is one of the main approaches in inventory
management that is well known for its simplicity. Theoretically, the EOQ concept is the most basic
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and traditional inventory model. The EOQ model is used to control inventory by ordering raw
materials in optimal quantities. By using EOQ, companies can plan the frequency and number of
orders for the most economical raw materials in a certain period. The implementation of EOQ helps
companies reduce storage costs and ordering costs, as well as overcome problems related to
inventory, thereby reducing the risks that may arise due to oversized inventory. This EOQ analysis
provides a clear estimate of the frequency and optimal amount of raw material purchases.
So the purpose of this study is to find out how to control the inventory of soybean raw materials
applied by the Rizqy Putra Fried Tofu factory, to find out the total cost of soybean raw material
inventory if the company establishes an Economic Order Quantity (EOQ) method policy, and to find
out the number of economical soybean raw material inventory orders after using the Economic Order
Quantity (EOQ) method.
2. Materials and Methods
Approach and Types of Research
The approach used in this study is a quantitative approach, which is an approach that uses
aspects of measurement, calculation, formula, and numerical data in every stage of research, starting
from research proposals, research processes, hypotheses, going to the field, data analysis, to writing
research reports.
This type of research uses a comparative descriptive method. Descriptive method is a research
method that aims to provide a systematic picture of scientific information obtained from the subject
or object of research. Descriptive research focuses on systematic explanations of facts discovered
during research. The goal is to create a systematic, factual, and accurate description, picture, or
painting of the facts, properties, and relationships between the phenomena investigated.
Comparative analysis is a research method that involves collecting, processing, and analyzing
various kinds of data with the aim of producing conclusions. The comparative method is used in this
study to find out how the comparison of inventory methods between the methods used by factories
with the Economic Order Quantity method can increase inventory cost efficiency.
Objek Penelitian
In conducting a study, the first thing to pay attention to is the object of research to be studied.
Where the object of research contains a problem that will be used as research material to find a
solution. The object of research that the author will examine is the Control of Raw Material Inventory
at the Rizqy Putra Fried Tofu Factory in Tanjungwangi Village, Cihampelas District, West Bandung
Regency.
Data Collection Techniques
The process of research and writing, the author uses data collection methods are as follows:
1. Interviews, in the interview process are carried out with conversations by two parties, namely
the interviewer and the interviewee. The interviewee gave answers to questions given by the
interviewer related to the issues discussed, which were conducted to the owner of the Fried
Tofu factory Rizqy Putra about the supply of raw materials in Tanjungwangi Village, Cihampelas
District, West Bandung Regency.
2. Observation, in the observation process, observations are made on ongoing processes or
activities, making observations on the raw material control system carried out by the Rizqy
Putra Fried Tofu factory in Tanjungwangi Village, Cihampelas District, West Bandung Regency.
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Data Analysis Methods
The method of data analysis in this study is divided into two methods, namely::
1. Tabular Approach
This method involves compiling a list or table that contains the order amount and annual fee.
The order with the lowest cost will be considered the most economical order.
Table 1 Economical order quantity breakdown
Order
Quantity
(order)
Order
Quantity
(order)
Average
setup
Storage costs
Ordering Cost
Total
cost/year
2. Formula Approach
In determining the amount of economical orders by mathematical formulas, the focus is on
minimizing inventory costs. This can be achieved by paying attention to the trade-off between holding
costs and ordering costs. The mathematical formula that is often used to find the economic order
quantity is to use the EOQ (Economic Order Quantity) economic model.
In the EOQ model, the number of economic orders (Q) can be calculated using the formula:
EOQ =
Information:
EOQ = Optimal number of items per order
D = Annual demand for inventory goods in units (Demand)
OC = Ordering Cost
CC = Carrying Cost
3. Results and Discussions
Basically, inventory management helps optimize the operational processes of manufacturing
companies by ensuring the smooth production and distribution process to customers. Each company
has a different approach to managing raw material inventory, including determining the amount of
raw materials, time of use, and the cost of purchasing raw materials. However, good raw material
inventory control is very important for every company to ensure the production process runs
smoothly (Novitasari, 2022). Without effective control, the production performance of a factory can
be disrupted.
Based on the results of interviews at Rizqy Putra Fried Tofu Factory, inventory control of
soybean raw materials is carried out in traditional or conventional ways. The company started by
estimating how much soybeans it would need based on previous sales. Then, the company orders
soybeans according to production needs and stores them well in warehouses, paying attention to
stock rotation to use longer soybeans first. This process is carried out without the use of advanced
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technology or information systems. In addition, the company also checks the quality of soybeans
received manually. In this way, the company can run fried tofu production smoothly and efficiently
even though it uses conventional methods in managing its raw material inventory.
The use of conventional methods in controlling the inventory of soybean raw materials at the
Rizqy Putra Fried Tofu Factory often experiences several problems, such as when soybean prices rise
which causes production costs or inventory costs to increase significantly. To overcome this problem,
companies can consider the application of the EOQ (Economic Order Quantity) method. With the EOQ
method, the company will calculate the optimal amount of raw materials that must be ordered each
time an order is placed, taking into account the cost of ordering and storage costs. Thus, companies
can reduce inventory costs by ordering the right amount according to production needs, thus avoiding
excess inventory that has the potential to result in high storage costs. In addition, companies may also
consider negotiating better prices with suppliers based on the larger volume of purchases resulting
from the implementation of the EOQ method. With this strategy, the company can maintain a balance
of production costs and ensure smooth operations even in the face of fluctuations in raw material
prices.
Data Analysis
1. Purchase of Raw Materials,
Rizqy Putra Fried Tofu Factory uses a conventional purchasing strategy where the purchase of
soybean raw materials is carried out regularly to meet production needs. Soybean purchasing
decisions are based on experience from previous periods, adjusted to future production needs.
Soybeans are ordered four times a month. Rziqy Putra Fried Tofu Factory uses imported soybeans
from America. Until now, the factory has not experienced problems with the quality of soybeans
received, because usually, the soybeans purchased are of good quality
Table 2 Soybean Raw Material Purchase Data
No.
Month
Total (kg)
1
January
6.000
2
February
6.000
3
March
5.500
4
April
6.000
5
May
6.500
6
June
5.000
7
July
6.000
8
August
6.000
9
September
5.500
10
October
6.000
11
November
6.000
12
December
6.000
Total
70.500
Average
5.875
Source: Rizqy Putra Fried Tofu Factory
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Based on table 2, it can be seen that in January and February Rizqy Putra Fried Tofu Factory
purchased 6,000 kg of soybean raw materials, but in March the purchases made decreased to 5,500
kg because there were still remaining supplies of soybean raw materials in the warehouse, then in
April soybean purchases became as usual at 6,000 kg, while in May soybean purchases increased to
6,500 kg, then in June soybean purchases decreased dramatically to 5,000 kg, in July and August
soybean purchases returned to normal by 6,000 kg, but in September soybean purchases decreased
again to 5,500 kg, then soybean purchases in October, November, and December became as usual at
6,000 kg. For a year, Rizqy Putra Fried Tofu Factory purchases a total of 75,000 kg of soybean raw
materials, with an average of 5,875 kg.
2. Use of Raw Materials,
The use of soybean raw materials at the Rizqy Putra Fried Tofu Factory in 2023 is 70,000 kg
with a frequency of purchases during 2023 48 times a year. Details of the use of soybean raw materials
in 2023 are presented in table 3 below:
Table 3 Raw Material Usage Data
No.
Month
Total (kg)
1
January
5.800
2
February
5.400
3
March
5.800
4
April
5.600
5
May
6.000
6
June
5.600
7
July
6.000
8
August
6.000
9
September
5.800
10
October
6.000
11
November
6.000
12
December
6.000
Total
70.000
Rata-rata
5.833
Source: Pabrik Tahu Goreng Rizqy Putra
Based on table 3 above, it shows the use of soybean raw materials at Rizqy Putra Fried Tofu
Factory which changes every month. Normally the use of soybean raw materials per month is as much
as 6,000 kg. The lowest use of soybean raw materials was in February, which was 5,400 kg. From the
data on the use of raw materials above, it shows that the total use of soybean raw materials during
2023 is 70,000 kg.
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3. Frekuensi Pemesanan
Order frequency at Rizqy Putra Fried Tofu Factory in table 4Source: Rizqy Fried Tofu Factory below:
Table 4 Booking Frequency,
Time
Purchase
Frequency of
Purchasing Soybean
Raw Materials
1 month
4 Kali
1 year
48 Kali
Source: Rizqy Putra Fried Tofu Factory
Rizqy Putra Fried Tofu Factory placed orders in one month, which is four times, so that in one
year the frequency of ordering soybean raw materials on as many as 48 orders.
4. Ordering Cost
Ordering Cost is the cost of expenses related to the process of ordering goods or materials by
the company. This cost is greatly influenced by the frequency of ordering raw materials. Based on the
results of the study, it is known that the components of the order costs incurred by the Rizqy Putra
Fried Tofu Factory are telephone costs which are credit tariff costs, and SMS costs used for
communication with suppliers, and transportation costs or shipping costs. Details of the cost of
ordering soybean raw materials at Rizqy Putra Fried Tofu Factory can be seen in Table 5 below:
Table 5 Ordering Cost
No.
Types of Fees
total (Rp.)
1.
Phone charges
Rp. 240.000
2.
Transportation Costs
Rp. 480.000
Total
Rp. 720.000
Source: Rizqy Putra Fried Tofu Factory
Based on table 5 above, it shows the cost of ordering soybean raw materials at the Rizqy Putra
Fried Tofu Factory is Rp. 720,000 for one year.
5. Carrying Cost,
Carrying Cost are costs incurred due to the storage of goods in the warehouse. The amount of
storage costs is influenced by the amount of raw material inventory. The soybean raw material
storage warehouse at Rizqy Putra Fried Tofu Factory is not separated from the production site of
making fried tofu. Therefore, the costs incurred for the storage of soybean raw materials are not too
high because the warehouse used is relatively simple. The details of the cost of ordering soybean raw
materials at the Rizqy Putra Fried Tofu Factory can be seen in table 6 belowi:
Table 6 Carrying Cost
No.
Types of Fees
Total (Rp.)
1.
Electricity Cost
Rp. 3.600.000
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2.
Labor Cost
Rp. 14.400.000
Total
Rp. 18.000.000
Source : Rizqy Putra Fried Tofu Factory
The total cost of storing soybean raw materials in 2023 is Rp. 18,000,000, which is used for
electricity costs and warehouse labor costs at the Rizqy Putra Fried Tofu Factory.
Soybean Raw Material Inventory Control Analysis
Calculations are very important in controlling the inventory of soybean raw materials at the
Rizqy Putra Fried Tofu Factory, to be able to minimize inventory costs consisting of ordering costs
and storage costs. Therefore, Rizqy Putra Fried Tofu Factory can produce fried tofu according to
consumer demand.
1. Tabular Approach
Table 7 Tabular Approach
Order
Quantity
(Order)
Number of
Units/Orders
(kg)
Average
Setup (kg)
Booking Fee
(Rp)
Storage Cost
(Rp)
Total Cost/year
(Rp)
1
70.500
35.251
720.000
18.000.000
18.720.000
2
35.250
17.626
1.440.000
9.000.000
10.440.000
3
23.500
11.752
2.160.000
6.000.000
8.160.000
4
17.625
8.815
2.880.000
4.500.000
7.380.000
5
14.100
7.053
3.600.000
3.600.000
7.200.000
6
11.750
5.878
4.320.000
3.000.000
7.320.000
7
10.071
5.039
5.040.000
2.571.429
7.611.429
8
8.813
4.410
5.760.000
2.250.000
8.010.000
9
7.833
3.921
6.480.000
2.000.000
8.480.000
10
7.050
3.530
7.200.000
1.800.000
9.000.000
11
6.409
3.210
7.920.000
1.636.364
9.556.364
12
5.875
2.944
8.640.000
1.500.000
10.140.000
13
5.423
2.718
9.360.000
1.384.615
10.744.615
14
5.036
2.525
10.080.000
1.285.714
11.365.714
15
4.700
2.358
10.800.000
1.200.000
12.000.000
16
4.406
2.211
11.520.000
1.125.000
12.645.000
17
4.147
2.082
12.240.000
1.058.824
13.298.824
18
3.917
1.967
12.960.000
1.000.000
13.960.000
19
3.711
1.865
13.680.000
947.368
14.627.368
20
3.525
1.773
14.400.000
900.000
15.300.000
21
3.357
1.689
15.120.000
857.143
15.977.143
22
3.205
1.613
15.840.000
818.182
16.658.182
23
3.065
1.544
16.560.000
782.609
17.342.609
24
2.938
1.481
17.280.000
750.000
18.030.000
25
2.820
1.423
18.000.000
720.000
18.720.000
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26
2.712
1.369
18.720.000
692.308
19.412.308
27
2.611
1.319
19.440.000
666.667
20.106.667
28
2.518
1.273
20.160.000
642.857
20.802.857
29
2.431
1.230
20.880.000
620.690
21.500.690
30
2.350
1.190
21.600.000
600.000
22.200.000
31
2.274
1.153
22.320.000
580.645
22.900.645
32
2.203
1.118
23.040.000
562.500
23.602.500
33
2.136
1.085
23.760.000
545.455
24.305.455
34
2.074
1.054
24.480.000
529.412
25.009.412
35
2.014
1.025
25.200.000
514.286
25.714.286
36
1.958
997
25.920.000
500.000
26.420.000
37
1.905
971
26.640.000
486.486
27.126.486
38
1.855
947
27.360.000
473.684
27.833.684
39
1.808
923
28.080.000
461.538
28.541.538
40
1.763
901
28.800.000
450.000
29.250.000
41
1.720
880
29.520.000
439.024
29.959.024
42
1.679
860
30.240.000
428.571
30.668.571
43
1.640
841
30.960.000
418.605
31.378.605
44
1.602
823
31.680.000
409.091
32.089.091
45
1.567
806
32.400.000
400.000
32.800.000
46
1.533
789
33.120.000
382.979
33.502.979
47
1.500
774
33.840.000
382.979
34.222.979
48
1.469
758
34.560.000
375.000
34.935.000
Total
314.345
157.761
846.720.000
80.250.024
926.970.024
Source: Processed Researchers (2024)
Based on table 7 above using the tabular approach shows the lowest total inventory cost, which
occurs when the frequency is 5 times with the number of orders as much as 14,100 kg, the average
inventory is 7,053 kg. The order cost incurred is Rp. 3,600,000 and storage costs are Rp. 3,600,000 so
that the total inventory costs incurred are Rp. 7,200,000.
Calculation of Number of Bookings:
Number of units/orders =
Number of units/orders =
= 14.100 kg
Ordering cost Calculation:
Ordering cost = Total ordering cost X ordering frequency
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Ordering cost = Rp. 720.000 X 5
= Rp. 3.600.000
Storage Cost Calculation:
Storage costs =
Booking fee =
= Rp. 3.600.000
Then the total cost of inventory with the tabular approach inventory model is:
Total inventory cost = Order fee + Storage fee
= 3.600.000 + 3.600.000
= 7.200.0000
Inventory costs with the policy implemented by Rizqy Putra Fried Tofu Factory, with a total
order frequency of 48 times a year, the total amount of inventory is 314,345 kg per year, the average
inventory in a year is 157,761 kg, with order costs incurred of Rp. 846,720,000, in a frequency of 48
orders and storage costs of Rp. 80,250,024. So that the total cost of soybean raw material inventory
at Rizqy Putra Fried Tofu Factory is Rp. 926,970,024 per year.
The tabular approach produces the lowest total inventory cost when the number of ordering
and storage costs is the same amount, which is at a frequency of 5 orders per year.
2. Formula Approach
The determination of the economical order quantity can be simplified in a mathematical
formula by noting that the minimum inventory cost occurs when the order cost equals the storage
cost.
1) Economic Order Quantity Method
Based on the results of the study, it show that the application of the EOQ method can optimize
inventory costs at Rizqy Putra Fried Tofu Factory, which in turn can increase profitability. However,
before determining the optimal number of orders in each order, it is necessary to pay attention to the
basic steps on which the calculation of EOQ is based, namely the period during which prices remain
stable, both for the purchase of raw materials and the cost of ordering and storage. In addition, it
requires constant availability of funds to make purchases at all times, assuming stable use of materials
over time. Ensure that raw materials are always available on the market and adequate storage
facilities are available, taking into account that they are not easily damaged when stored in
warehouses.
Analysis is used to determine the number of orders that can optimize inventory costs, Rizqy
Putra Fried Tofu Factory can use the Economic Order Quantity (EOQ) method. With the EOQ method,
it can be known the number of economical soybean raw material orders that must be made at the
time of purchase.
According to Rizqy Putra Fried Tofu Factory, the total purchase of soybean raw materials issued
in 2023 is 70,500 kg with a frequency of 48 orders a year or four times a month. The amount of raw
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materials used is 70,000 kg in 2023. The order fee incurred is Rp. 720,000 and the storage fee is Rp.
18,000,000 in 2023.
The calculation to calculate the cost of ordering soybean raw materials is as follows:
Cost per message =
=
= Rp. 15.000
It is known that the total order cost incurred by Rizqy Putra Fried Tofu Factory is Rp. 720,000,
with a frequency of ordering 48 times a year. Based on the calculation above, the cost of ordering
soybean raw materials is Rp. 15,000 for each order.
The calculation for calculating the storage cost of soybean raw materials is as follows:
Storage Cost =
=
= Rp. 255
The calculation to calculate the number of economical orders using the EOQ method is as
follows:
Economic Order Quantity Calculation:
EOQ =
EOQ =
EOQ =
EOQ =
EOQ =
EOQ = 2.880 Kg
Based on data obtained from Rizqy Putra Fried Tofu Factory, the purchase of soybean raw
materials is as much as 70,500 kg. from calculations using the Economic Order Quantity (EOQ) method,
it is obtained that the number of orders for soybean raw materials that can be ordered is as much as
2,880 kg so that the costs incurred are more economical.
The calculation for the average inventory of soybean raw materials in a year that can be done
by Rizqy Putra Fried Tofu Factory is:
Average setup =
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=
= 1.440 kg
It is known that the purchase obtained from the calculation with the Economic Order Quantity
(EOQ) method is as much as 2,880 kg, so that the calculation above shows the average inventory of
soybean raw materials which is as much as 1,440 kg.
Calculation To calculate the number of order frequencies estimated in each message using the
Economic Order Quantity (EOQ) method is:
Estimated booking frequency =
F =
F = 24 times
It is known that the need for soybean raw materials at the Rizqy Putra Fried Tofu Factory is
70,500 kg, with an economical order amount obtained using the Economic Order Quantity (EOQ)
method of 2,880 kg. Based on the results of research conducted at Rizqy Putra Fried Tofu Factory, the
frequency of ordering from the calculation above using the EOQ method shows that the frequency
that can be done by Rizqy Putra Fried Tofu Factory is 24 times a year. Meanwhile, what is done by
Rizqy Putra Fried Tofu Factory is 48 times a year. So that Rizqy Putra Fried Tofu Factory can minimize
the frequency of ordering soybean raw materials.
Calculation to calculate the annual booking fee using the EOQ method:
Booking fee =
=
= Rp. 367.187 / year
It is known that the need for soybean raw materials is 70,500 kg, with the number of economical
orders obtained by calculating the Economic Order Quantity (EOQ) method of 2,880 kg, and the cost
of each order is Rp. Rp. 15,000. Based on the calculation above, the amount of order costs that can be
incurred by Rizqy Putra Fried Tofu Factory is Rp. 367,187 for orders per year.
Calculation to calculate annual storage costs using the EOQ method:
Storage costs =
x H
=
x Rp. 255/kg
= Rp. 367.200 / year
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It is known that the number of economical orders obtained using the Economic Order Quantity
(EOQ) method is 2,880 kg, and the storage cost per kg is Rp. 255 kg. Based on the calculation above,
the amount of storage costs that can be incurred by Rizqy Putra Fried Tofu Factory is Rp. 367,200 per
year.
Discussion
Based on the analysis of the inventory model, it can be seen that the tabular approach shows
the lowest amount of inventory costs at a frequency of 5 times, with a large number of unit inventory
/ order orders of 14,100 with an average inventory of 7,053 kg, storage costs and order costs of Rp.
3,600,000, so that inventory costs incurred are Rp. 7,200,000.
In the calculation model with a formula approach approach , economic orders are obtained
using the Economic Order Quantity (EOQ) method, which shows many units / orders of 2,880 kg, with
an average inventory of 1,440 kg. Based on the frequency calculation in the Economic Order Quantity
(EOQ) method, the number of orders that are estimated to be made is 24 times. The cost of ordering
in the preparation model using the Economic Order Quantity (EOQ) method shows the total cost
incurred is Rp. 367,187 / year. While the storage costs incurred are Rp. 367,200 / year, so that the
total inventory costs incurred are Rp. 734,387 / year.
Based on the inventory model above, the calculation with the Economic Order Quantity (EOQ)
approach formula approach, can be better to apply because in the Economic Order Quantity (EOQ)
method, order costs and storage costs have decreased, so as to minimize the costs incurred by the
Rizqy Putra Fried Tofu Factory and can maximize the profits obtained.
4. Conclusion
Based on the results of research and discussion in the previous chapter, a conclusion can be
drawn as follows: Based on the results of an interview with the Rizqy Putra Fried Tofu Factory, it can
be seen that the control of soybean raw material inventory carried out by the company is only by
conducting warehouse observations or can be called conventional methods. Based on the calculation
of the inventory model with the Economic Order Quantity (EOQ) approach formula, it can be seen that
the total inventory cost that must be incurred by the Rizqy Putra Fried Tofu Factory is Rp. 734,387 /
year with a frequency of ordering 24 times a year, meaning it is very economical compared to the
inventory costs incurred so far by the Rizqy Putra Fried Tofu Factory with a frequency of orders made
48 times a year. Based on the calculation of the inventory model with the Economic Order Quantity
(EOQ) approach formula approach, it shows an economical order quantity of 2,880 kg, can reduce
order costs and storage costs, so as to minimize inventory costs incurred at the Rizqy Putra Fried Tofu
Factory and can maximize the profits obtained.
5. References
Akhmad, D., & SE, M. (2018). Manajemen Operasi (Teori dan Aplikasi dalam Dunia Bisnis). Bogor:
Azkiya Publishing.
Anista, T., & Widiyastuti, T. (2016). Analisis pengelolaan persediaan bahan baku untuk meningkatkan
produksi guna memenuhi permintaan konsumen pada UD Nanda Putri Srengat Blitar. Jurnal
Penelitian Manajemen Terapan (PENATARAN), 1(1), 92–103.
Assauri, S. (2012). Manajemen Pemasaran: Vol. Cetakan Kesepuluh. Rajawali Pers.
e-ISSN: 2723-6692 🕮 p-ISSN: 2723-6595
Journal of Indonesian Social Sciences, Vol. 5, No. 6, June 2024 1331
Assauri, S. (2019). Manajemen Produksi dan Operasi. Lembaga penerbit Fakultas Ekonomi Universitas
Indonesia.
Fajrin, E. H., & Slamet, A. (2016). Analisis Pengendalian Pesediaan Bahan Baku dengan Menggunakan
Metode Economic Order Quantity (EOQ) pada Perusahaan Roti Bonansa. Management Analysis
Journal, 4(5).
Haryadi, D., & Bramasto, A. (2023a). Study of Inventory Control and Quality Control of Raw Materials.
Almana: Jurnal Manajemen Dan Bisnis, 7(3), 613–621.
Haryadi, D., & Bramasto, A. (2023b). Study of Inventory Control and Quality Control of Raw Materials.
Almana: Jurnal Manajemen Dan Bisnis, 7(3), 613–621.
Heizer, J. D. (2015). Manajemen Operasi: Manajemen Keberlangsungan dan Rantai Pasokan (Edisi 11).
Salemba Empat.
Heizer, J., Render, B., & Munson, C. (2020). Operations Management: Sustainability and Supply Chain
Management. Pearson Education London.
Herjanto, E. (2017). Manajemen Operasi: Vol. Cetakan ke 7 (Edisi Ke 3). PT. Gramedia.
Julyanthry, J., Siagian, V., Asmeati, A., Hasibuan, A., Simanullang, R., Pandarangga, A. P., Purba, S., Purba,
B., Pintauli, R. F., Rahmadana, M. F., & Syukriah M, E. A. (2020). Manajemen Produksi dan Operasi:
Vol. Cet 1. Kita Menulis.
Muksin, M. (2023). Economic Order Quantity (EOQ) Application to Raw Material Inventory Control
for SME’s. Community Service Journal (CSJ), 5(2), 88–98.
Novitasari, D. (2022). Manajemen Operasi Konsep dan Esensi. STIE Widya Wiwaha.
Sulistyowati, K. D., & Huda, I. U. (2021). Analisis Pengendalian Persediaan pada PT. Bima (Berkah
Industri Mesin ANGKAT) Cabang Banjarmasin . JIEB: Jurnal Ilmiah Ekonomi Bisnis, 7(3), 430–
440. https://ejournal.stiepancasetia.ac.id/jieb/article/view/666/461
Turnip, M. S. K. (2017). Analisis Perbandingan Persediaan Bahan Baku Methanol antara Pendekatan
Model Economic Order Quantity dengan Just Time pada CV Mamabros Servicindo Batam. Ournal
of Applied Managerial Accounting, 1(2), 1–15.
