JP2006139796A - Stock planning method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problems wherein existing techniques of stock control/planning involve stock and delivery problems depending on fluctuating demand and correspondingly must have a large stock as a safety stock. <P>SOLUTION: A stock planning server 100 receives demand and supply characteristics of merchandise, lead time on the distribution channel of the merchandise, and a planning cycle from a production management server 200, a transportation management server 300 and a sales management server 400, and uses them in calculating a necessary stock. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a technology for executing inventory management of merchandise. In particular, the present invention relates to a simulation technique for calculating a target value of a necessary inventory amount that is appropriate for more efficient production and transportation.

Conventionally, there is JP-A-8-235274 as a prior art for executing inventory management of merchandise. This prior art uses both the “MRP method” and the “JIT method”. More specifically, JIT items can be handled even though it is an MRP method, the inventory forecast of JIT items can be performed, and the validity of the “kanban number” and “order quantity” can be verified. An inventory management system is disclosed in which an update cycle is shortened by shortening an update time (“number of kanbans” and “order quantity”), and a procurement activity that follows a change in the market is performed.
JP-A-8-235274

  However, in the above-described conventional technology, there is a problem that a problem occurs in inventory and delivery according to a change in demand. Also, due to this problem, a large amount of inventory had to be kept as a safety stock.

  This is simply a combination of the “MRP method” and the “JIT method”. First, in the “MRP method”, the production quantity is leveled, and the inventory quantity is adjusted according to the fluctuating demand quantity. For this reason, in the “MRP method”, highly accurate demand prediction is performed to reduce the inventory. However, if the accuracy of demand forecasting is not high, excess or shortage of inventory will become apparent. That is, conventionally, the target value cannot be accurately simulated.

  In the “JIT method”, the inventory quantity is leveled, and the production quantity is adjusted according to the changing demand quantity. In addition, since the “JIT method” does not have a safety stock corresponding to demand fluctuation, if the accuracy of the kanban size is poor, a shortage or delivery delay occurs.

  The above-mentioned conventional techniques cannot be solved simultaneously with the shortage of inventory and the shortage / delivery delay due to the mere combination of “MRP method” and “JIT method”.

  For this reason, if the target value of an appropriate inventory amount is calculated, the above-described problem can be solved. Moreover, if this target value is calculated by changing the conditions and executing the simulation, it is possible to calculate a target value more suitable for the situation.

  Therefore, in the present invention, from the demand characteristics and supply characteristics that are relative ratios of the moving average demand amount during a predetermined period and the standard deviation indicating the variation in the demand amount, the necessary inventory amount required for the distribution route of the product is calculated. A target value for a predetermined period is calculated. Furthermore, the present invention includes changing target conditions such as moving average demand and simulating a target value. Further, the present invention includes that the target value is the necessary inventory months. Here, the necessary inventory months is information indicating an inventory amount necessary for selling for a predetermined period.

  In addition, the lead time in the specification of the present application indicates a delivery period of a product from a product supply source to a demand destination including a store. The planning cycle indicates a period of inventory planning performed periodically.

  Further, the supply characteristics include a safety stock coefficient or a service rate indicating a rate at which the product is not missing.

  According to the present invention, since it is possible to calculate various necessary months of inventory for each demand characteristic and supply characteristic, it is possible to simulate the target value of the inventory quantity.

  First, the application destination in the embodiment of the present invention will be described. In the present embodiment, the present invention is applied to an inventory plan on a distribution channel in which a product produced by a production company is transported to a store by the transportation means of the transportation company and sold. That is, the effective inventory amount in each of the production company, the shipping company, and the sales store is calculated. In this case, there may be a plurality of production companies, shipping companies, and sales stores that handle the target product.

  Further, the production company uses a production management server 200 described later to manage the production and grasp the production status. In addition, the shipping company uses the shipping management server 300 described later to manage shipping and grasp the shipping status. Further, the store uses a sales management server 400 (to be described later) to manage sales and grasp the sales status.

  Here, FIG. 1 is a system configuration diagram showing the configuration of the inventory planning system of the present embodiment. The inventory planning system includes an inventory planning server 100, a production management server 200, a transportation management server 300, and a sales management server 400 that are connected via a network 500. There may be a plurality of these servers. In particular, the production management server 200, the transportation management server 300, and the sales management server 400 are numbers according to the form of the distribution route.

  Further, the inventory planning server 100 may be integrated with any one of the production management server 200, the transportation management server 300, and the sales management server 400. Furthermore, each of the inventory planning server 100, the production management server 200, the transportation management server 300, and the sales management server 400 may be a computer having a general structure, and performs processing according to a program that can be stored in a storage device. Execute.

  Each truck terminal 350 can be used by a transportation means such as a truck or a ship, and may be connected to the network 500 or to another network to which the transportation management server 300 is connected. The truck terminal 350 may also be a computer having a general structure, and executes processing according to a program that can be stored in a storage device.

  Next, simulation in the present embodiment will be described with reference to the flowcharts shown in FIGS.

  The inventory planning server 100 stores an inventory planning table 120. Here, each item of the inventory plan table 120 receives an input to the inventory plan server 100 from another server or user at a predetermined timing. Moreover, you may make it the structure calculated from another item. Specifically, it is as follows.

First, the moving average demand amount Qd15 is received from the sales company server 400. The standard deviation Σd60 may be calculated by the sales company server 400 or the inventory planning server 100 using the following (Equation 1).
σd = √ (Σ (Qd−Qd (i) ² / (tm−1)) (Equation 1)
Further, Qd (i), which is the actual sales amount, is also received from the sales company server 400. Further, the store sales amount that is the amount that can be sold at the sales company, and the store arrival amount that indicates the amount of products that have arrived at the sales company are received from the sales company server 400. It should be noted that a value that is obtained by adding each of the store sales possible amount and the store arrival amount may be handled as one piece of information.

  First, in step 1000, the inventory planning server 100 receives inputs of a product ID 90 for identifying a product 1 to be planned, a planning cycle C10, a lead time L20, a service rate s30, and a moving average period tm40. These pieces of input information are input from an inventory manager who is a user of the inventory planning server.

  These pieces of information may be in accordance with the contents of a product sales strategy established by an inventory manager or the like. The planning cycle C10 is a value according to the product sales plan for “how much time cycle to supply”. In addition, the lead time L20 indicates the time when the product is distributed from the production base to the sales base. Further, the service rate s30 is a value according to the product sales plan that indicates how much the product is not to be out of stock.

  As will be described later, the information input in step 1000 may be configured to input a value when actually used in addition to manual input.

  Next, in step 1001, the inventory planning server 100 requests the sales management server 400 for the actual demand amount of the product 1 in a predetermined period. For example, the inventory planning server 100 sends request information including the product ID 90 and the moving average period tm40 to the sales management server 400.

  Next, in step 1002, the sales management server 400 calculates a demand amount record corresponding to the sent request information. Using the sent product ID 90 as a search key, the sales amount for the moving average period tm40 is searched from the sales result DB 410 shown in FIG. 3, and this is calculated as the demand amount result.

  Next, in step 1003, the sales management server 400 transmits the calculated demand volume result to the inventory planning server 100.

Next, the inventory management server 100 calculates a moving average demand amount Qd15 of the demand amount from the demand amount result received in step 1004. This is an average value of the actual demand amount for each predetermined partial moving average period constituting the moving average period tm40. For example, when the moving average period tm40 is one year, the partial moving average period is one week. In this case, the moving average demand amount Qd15 is calculated by dividing the actual demand amount by 52 (weeks) constituting one year. The moving average demand amount Qd15 may be calculated using the following (Equation 2).
(Qd = Σ (Qd (i)) / tm) (Equation 2)
In addition, the inventory planning server 100 stores the calculated moving average demand amount Qd15 at a location corresponding to the product ID 90 in the column 122 of the inventory planning table 120 shown in FIG.

Note that the sales management server 400 calculates the latest partial moving average period sales amount to the inventory planning server 100 in step 1002 and sends the calculated sales amount to the inventory management server 100 in step 1003. Good. In this case, the inventory planning server 100 uses the sales amount DB (past portion) 110 shown in FIG. 5 and the sales amount sent as the sales amount managed in the partial moving average period transmitted before that,
The moving average demand amount Qd15 is calculated.

  Note that step 1006 may be executed by the sales management server 400. That is, the sales management server 400 calculates the moving average demand amount Qd15 and sends it to the inventory planning server 100.

  Next, in step 1007, the inventory planning server 100 determines whether trend correction is necessary. If trend correction is necessary, correction is executed in step 1008 and the process proceeds to step 1009. The trend correction is to correct the moving average demand amount Qd15 according to the increase / decrease trend of the demand. In step 1007, when the increase / decrease tendency exceeds a predetermined value, it is determined that trend correction is necessary. Details of the trend correction will be described later.

  Next, in step 1009, a standard deviation σd60 of the moving average demand amount Qd15 is calculated. The standard deviation σd60 may be calculated using the above (Equation 1).

  Next, in Step 1010, the inventory planning server 100 calculates the safety stock coefficient k70 from the service rate s30 using the safety coefficient calculation table 150 shown in FIG. That is, the safety stock coefficient k70 corresponding to the service rate s30 input in step 1000 is selected in the safety coefficient calculation table 150.

  Here, in step 1010, the inventory planning server 100 can accept a plurality of inputs of service rates s desired to be simulated from the user. For example, an input of an appropriate service rate s is accepted according to the sales strategy of the product. As a result, it is possible to calculate the necessary inventory months for each of the plurality of safety factors.

Next, in Step 1011, the inventory planning server 100 determines whether or not the safety stock coefficient k70 calculated in Step 1010 needs to be corrected. When correction is necessary, correction is performed using the safety stock coefficient correction table 160.

  Here, in step 1011, whether or not correction is necessary is determined according to the distribution of the moving average demand amount Qd15. That is, when at least one of the kurtosis and σd / Qd of this distribution exceeds a predetermined threshold value, it is determined that correction is necessary. The reason for this is that the required inventory is based on the assumption that normal demand is normally distributed. However, the actual demand distribution is not a normal distribution, and the base is wider than the normal distribution, or the kurtosis is higher than the normal distribution. In these cases, the service rate will not correspond to the actual demand.

  Therefore, in step 102, using a safety stock coefficient correction table 160 corresponding to the expected service rate s30, for a demand with a kurtosis higher than a threshold value, the larger the kurtosis becomes, the larger the safety stock coefficient becomes σd ( For demands where / Qd) is greater than the threshold, the safety stock coefficient is corrected to be smaller as the demand increases.

Next, in step 1013, the inventory planning server 100 calculates the necessary inventory quantity I using the sum of the planning cycle C10 and the lead time L20, the moving average demand quantity Qd15, the safety inventory coefficient k70, and the standard deviation σd. To do. More specifically, the required inventory quantity I is calculated using the following (Equation 3).
(Equation 3)
I = Qd (L + C) + k√ (L + C) · σd
Note that there is a time difference between the time when the replenishment request amount is calculated and the time when the product actually reaches the store. That is, in steps 1005 to 1008, the inventory planning server 100 calculates the moving average demand amount Qd based on the current inventory status. In order to fill this time difference, each moving average demand amount up to after the lead time C20 may be calculated, and the necessary demand amount may be calculated based on this. These moving average demands are calculated as follows. (1) based on human prediction, (2) using the moving average demand Qd calculated in steps 1005 to 1008, and (3) using the computer such as the inventory planning server 100 to perform prediction. In any method, the input of the moving average demand amount at each timing is accepted, and the input value of each item of the inventory plan table 120 at each timing is calculated based on the inputted moving average demand amount, and the necessary inventory is based on this. The amount is calculated sequentially for each timing. This is because each item at the next timing changes according to the necessary inventory amount (replenishment request amount).

  Next, the trend correction in steps 1007 to 1008 will be described. First, in step 1007, it is determined that trend correction is necessary when the degree of change in demand that occurs with time exceeds a reference. The degree of change is determined as follows.

First, the actual demand Qd (i) at each time point is obtained from the item 127 of the inventory plan table 120. Next, for each time point, the demand record Qd (i) before the predetermined period from each time point
As well. Next, these differences are calculated, and this difference is compared with a predetermined value.
If the number of cases where the difference as a result of comparison exceeds a predetermined value is greater than the predetermined number, it is determined that trend correction is necessary. A planning cycle C10 is included before the predetermined period. Further, the predetermined value and the predetermined number may be input from a user of the inventory planning server 100.

  Next, in step 1008, trend correction is executed. First, using the actual demand recorded in the item 127 of the inventory plan table 120, an approximate expression of demand fluctuation in a preset period is obtained. Using this approximate expression, the moving average demand amount Qd is corrected to the moving average demand amount at the time point ahead of the lead time C20. Thus, the trend correction is completed.

  Here, the required inventory quantity I80 is calculated for the number of s (k calculated in step 1012) input in step 1000.

Next, in Step 1013, the inventory planning server 100 accepts the input of the moving average demand amount Qd ′ input from the user. With respect to the moving average demand amount Qd ′, it is possible to accept a plurality of inputs in the same manner as the service rate s. Step 1013 may accept the moving average demand amount Qd ′ transmitted from another device connected via the network. The other devices include at least one of the production management server 200, the transportation management server 200, the truck terminal 350, and the sales management server 400. In particular, the Qd ′ input according to the sales plan of the corresponding sales base may be received from the sales management server 100.

  The moving average demand amount Qd ′ is an average value of the demand amount in units of a predetermined period. For this reason, the inventory planning server 100 may accept the input of the demand amount of the product, the period during which the demand amount can be expected, and the unit period of the Qd ′ to be obtained, and execute the following information processing. It is calculated by calculating an average per unit period of the demand amount during the expected period. For example, if 120 demands can be expected in one year and the unit period is one month, 120 pieces are divided by 12 months and 12 pieces are calculated as Qd ′. In addition to the number of months, the unit period includes weekly units, yearly units, daily units, and the like.

Next, in step 1014, the required inventory months are calculated using each of the calculated required inventory quantity I80 and the input Qd ′. That is, when the required inventory quantity I is calculated as I (1), I (2), and the moving average demand quantity Qd ′ is input as Qd ′ (1), Qd ′ (2), Qd ′ (3), The necessary number of months of inventory is calculated using the following (Equation 4).
(Equation 4)
Required inventory months (1) = I (1) / Qd '(1)
Required inventory months (2) = I (1) / Qd '(2)
Required inventory months (3) = I (1) / Qd '(3)
Required inventory months (4) = I (2) / Qd '(1)
Required inventory months (5) = I (2) / Qd '(2)
Required inventory months (6) = I (3) / Qd '(3)
As described above, according to the present embodiment, it is possible to calculate various necessary months of inventory for each demand characteristic and supply characteristic.

  Further, the present embodiment includes displaying the output of the required inventory months in correspondence with the demand characteristics including Qd ′ and the demand amount and the supply characteristics including the service rate (safety factor). For example, the necessary inventory months may be displayed in each cell of the matrix with the demand amount on the vertical axis and the service rate on the horizontal axis. Furthermore, this matrix may be used as an input interface. That is, each item displays a blank matrix, and an input of a demand amount is received for each cell of the displayed vertical axis, and an input of a service rate is received on the horizontal axis. Then, the necessary inventory months calculated as described above are displayed in the input cells for both the vertical axis and the horizontal axis. The items on the vertical axis and the horizontal axis may be reversed. Further, the items on the vertical axis and the horizontal axis may be other items indicating demand characteristics and supply characteristics.

The present embodiment also includes the following configuration. When performing the simulation, in addition to the demand characteristic (Qd) and the supply characteristic (service rate = safety inventory coefficient), the lead time (L) and the planning cycle (C) may be used as parameters. In this case, Qd and service rate s do not necessarily have to be input as parameters. In this case, each variable composing the above-mentioned formula 2 (Qd (L + C) + k√ (L + C) σd) becomes a parameter.
As described above, according to the present invention, it is possible to simulate the target value of the inventory quantity.

It is a system configuration figure of one embodiment in the present invention. It is a flowchart (the 1) which shows the flow of the process in one embodiment in this invention. It is a figure which shows an example of store performance DB410. It is a figure which shows an example of stock management DB420. It is a figure which shows an example of sales performance DB (past part) 110. It is a figure which shows an example of dispatch DB130. It is a figure which shows an example of the stock plan table. It is a figure which shows an example of the service rate of 95% among the safety stock coefficient calculation tables. It is a figure which shows an example of production plan / result DB210. It is a figure which shows an example of transportation management DB310. It is a flowchart (the 2) which shows the flow of the process in one embodiment in this invention. It is a flowchart (the 2) which shows the flow of the process in one embodiment in this invention.

Explanation of symbols

Planning cycle ... 10, moving average demand amount ... 15, lead time L ... 20, service rate s ... 30, moving average period tm ... 40, standard deviation σd ... 60, safety stock coefficient k ... 70, necessary stock amount I ... 80 , Product ID ... 90, inventory planning server ... 100, production management server ... 200, transportation management server 300, sales management server 400, network ... 500,

Claims (6)

In an inventory target value calculation method for calculating a target value of an inventory amount of a product that circulates a distribution channel using a computer,
A process according to an inventory planning program stored in the storage device of the computer, the process being
Storing plan cycle data and lead time data in distribution of the commodity received from the outside in an inventory plan table stored in the storage device;
The demand amount actual data received by the computer in response to a request including information specifying the product and information of a predetermined period transmitted from the computer to another computer connected via a network, and the predetermined period length Obtaining a plurality of demand amount actual data indicating the demand amount of the product in different but different past sections;
Acquiring moving average demand amount data indicating an average value of the demand amount actual data of the plurality of sections and storing it in the inventory plan table;
Calculating standard deviation data of the moving average demand data;
Receiving an input of the service rate of the product from outside, obtaining a safety stock coefficient corresponding to the service rate from a safety stock coefficient calculation table stored in a storage device of the computer;
The storage device of the computer according to the relationship between the ratio of the moving average demand data to the standard deviation data and a predetermined threshold, or the relationship between the kurtosis of the distribution of the moving average demand data and the predetermined threshold The safety stock coefficient is corrected using the safety stock coefficient correction table stored in the table, and when the kurtosis is higher than a threshold value, the larger the kurtosis is, the larger the safety stock coefficient is, and the ratio is larger than the threshold value. In some cases, the step of correcting to a smaller safety stock factor as it increases,
Calculating the required inventory of the product using the moving average demand data, the lead time data, the planned cycle data, the standard deviation, and the safety stock coefficient;
Calculating required inventory months based on the moving average demand and the required inventory;
An inventory target value calculation method characterized by comprising: In an inventory target value calculation method for calculating a target value of an inventory amount of a product that circulates a distribution channel using a computer,
A process according to an inventory planning program stored in the storage device of the computer, the process being
Storing plan cycle data and lead time data in distribution of the commodity received from the outside in an inventory plan table stored in the storage device;
The demand amount actual data received by the computer in response to a request including information specifying the product and information of a predetermined period transmitted from the computer to another computer connected via a network, and the predetermined period length Obtaining a plurality of demand amount actual data indicating the demand amount of the product in different but different past sections;
Acquiring moving average demand amount data indicating an average value of the demand amount actual data of the plurality of sections and storing it in the inventory plan table;
Calculating standard deviation data of the moving average demand data;
Receiving an input of the service rate of the product from outside, obtaining a safety stock coefficient corresponding to the service rate from a safety stock coefficient calculation table stored in a storage device of the computer;
The storage device of the computer according to the relationship between the ratio of the moving average demand data to the standard deviation data and a predetermined threshold, or the relationship between the kurtosis of the distribution of the moving average demand data and the predetermined threshold The safety stock coefficient is corrected using the safety stock coefficient correction table stored in the table, and when the kurtosis is higher than a threshold value, the larger the kurtosis is, the larger the safety stock coefficient is, and the ratio is larger than the threshold value. In some cases, the step of correcting to a smaller safety stock factor as it increases,
Calculating the required inventory of the product using the moving average demand data, the lead time data, the planned cycle data, the standard deviation, and the safety stock coefficient;
Calculating the required inventory months based on the moving average demand for one month inputted to the computer from the outside and the required inventory quantity;
An inventory target value calculation method characterized by comprising: In an inventory target value calculation method for calculating a target value of an inventory amount of a product that circulates a distribution channel using a computer,
A process according to an inventory planning program stored in the storage device of the computer, the process being
Storing plan cycle data and lead time data in distribution of the commodity received from the outside in an inventory plan table stored in the storage device;
The demand amount actual data received by the computer in response to a request including information specifying the product and information of a predetermined period transmitted from the computer to another computer connected via a network, and the predetermined period length Obtaining a plurality of demand amount actual data indicating the demand amount of the product in different but different past sections;
Acquiring moving average demand amount data indicating an average value of the demand amount actual data of the plurality of sections and storing it in the inventory plan table;
Calculating standard deviation data of the moving average demand data;
Receiving an input of the service rate of the product from outside, obtaining a safety stock coefficient corresponding to the service rate from a safety stock coefficient calculation table stored in a storage device of the computer;
The storage device of the computer according to the relationship between the ratio of the moving average demand data to the standard deviation data and a predetermined threshold, or the relationship between the kurtosis of the distribution of the moving average demand data and the predetermined threshold The safety stock coefficient is corrected using the safety stock coefficient correction table stored in the table, and when the kurtosis is higher than a threshold value, the larger the kurtosis is, the larger the safety stock coefficient is, and the ratio is larger than the threshold value. In some cases, the step of correcting to a smaller safety stock factor as it increases,
Calculating the required inventory of the product using the moving average demand data, the lead time data, the planned cycle data, the standard deviation, and the safety stock coefficient;
Obtains the second moving average demand data indicating the average value of demand in units of a predetermined period, and calculates the required inventory months based on the second moving average demand data and the required inventory And steps to
An inventory target value calculation method characterized by comprising: In the inventory target value calculation device that calculates the target value of the inventory quantity of the product that circulates the distribution channel, the device has the following configuration.
An input device for receiving input of planned cycle data and lead time data in the distribution of the product;
Storage device for storing data and inventory planning program,
A computer that executes processing according to the data and the inventory planning program,
Means for obtaining a plurality of demand amount actual data indicating the demand amount of the product in the past section having a different predetermined period length, which is demand amount actual data;
Means for obtaining first moving average demand amount data indicating an average value of the demand amount actual data of the plurality of sections;
Means for calculating standard deviation data of the first moving average demand data;
Means for obtaining a safety stock coefficient corresponding to a service rate of the product from a safety stock coefficient calculation table stored in a storage device of the computer;
According to the relationship between the ratio of the first moving average demand data to the standard deviation data and a predetermined threshold, or the relationship between the kurtosis of the distribution of the first moving average demand data and the predetermined threshold , Means for correcting the safety stock coefficient using a safety stock coefficient correction table stored in the storage device of the computer, and if the kurtosis is higher than a threshold, the greater the kurtosis, the larger the safety stock coefficient, Means for correcting to a smaller safety stock factor as the ratio is greater than a threshold,
Means for calculating a necessary stock quantity of the product using the first moving average demand data, the lead time data, the plan cycle data, the standard deviation, and the safety stock coefficient;
A computer comprising: means for calculating required inventory months based on the moving average demand and the required inventory;
An inventory target value calculation device comprising: In the inventory target value calculation device that calculates the target value of the inventory quantity of the product that circulates the distribution channel, the device has the following configuration.
An input device for receiving input of planned cycle data and lead time data in the distribution of the product;
Storage device for storing data and inventory planning program,
A computer that executes processing according to the data and the inventory planning program,
Means for obtaining a plurality of demand amount actual data indicating the demand amount of the product in the past section having a different predetermined period length, which is demand amount actual data;
Means for obtaining moving average demand amount data indicating an average value of the demand amount actual data of the plurality of sections;
Means for calculating standard deviation data of the moving average demand data;
Means for obtaining a safety stock coefficient corresponding to a service rate of the product from a safety stock coefficient calculation table stored in a storage device of the computer;
The storage device of the computer according to the relationship between the ratio of the moving average demand data to the standard deviation data and a predetermined threshold, or the relationship between the kurtosis of the distribution of the moving average demand data and the predetermined threshold Means for correcting the safety stock coefficient using the safety stock coefficient correction table stored in the table, wherein when the kurtosis is higher than a threshold value, the larger the kurtosis is, the larger the safety stock coefficient is, and the ratio is larger than the threshold value. In some cases, a means to correct for a smaller safety stock factor,
Means for calculating a necessary stock quantity of the product using the moving average demand data, the lead time data, the plan cycle data, the standard deviation, and the safety stock coefficient;
A computer comprising: means for calculating a required number of months of inventory based on a moving average demand for one month input to the computer from the outside and the required inventory quantity;
An inventory target value calculation device comprising: In the inventory target value calculation device that calculates the target value of the inventory quantity of the product that circulates the distribution channel, the device has the following configuration.
An input device for receiving input of planned cycle data and lead time data in the distribution of the product;
Storage device for storing data and inventory planning program,
A computer that executes processing according to the data and the inventory planning program,
Means for obtaining a plurality of demand amount actual data indicating the demand amount of the product in the past section having a different predetermined period length, which is demand amount actual data;
Means for obtaining moving average demand amount data indicating an average value of the demand amount actual data of the plurality of sections;
Means for calculating standard deviation data of the first moving average demand data;
Means for obtaining a safety stock coefficient corresponding to a service rate of the product from a safety stock coefficient calculation table stored in a storage device of the computer;
The storage device of the computer according to the relationship between the ratio of the moving average demand data to the standard deviation data and a predetermined threshold, or the relationship between the kurtosis of the distribution of the moving average demand data and the predetermined threshold Means for correcting the safety stock coefficient using the safety stock coefficient correction table stored in the table, wherein when the kurtosis is higher than a threshold value, the larger the kurtosis is, the larger the safety stock coefficient is, and the ratio is larger than the threshold value. In some cases, a means to correct for a smaller safety stock factor,
Means for calculating a necessary stock quantity of the product using the moving average demand data, the lead time data, the plan cycle data, the standard deviation, and the safety stock coefficient;
Obtains the second moving average demand data indicating the average value of demand in units of a predetermined period, and calculates the required inventory months based on the second moving average demand data and the required inventory A computer comprising means for
An inventory target value calculation device comprising:

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