JP2006155365A - Material order quantity determination system, material order quantity determination program, and material order quantity determination method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress the occurrence of surplus stock of materials due to a shift in demand prediction while preventing breakage of material orders.
An additional order requirement storage for a material used for manufacturing a product is stored in association with an additional order requirement amount that is a quantity that has been delivered from a supplier but has not yet been ordered. From the means, the additional order required amount at a certain time is read, and the surplus data indicating the amount of surplus as the amount that the supplier can supply the material is associated with the time is received in time series a plurality of times, and the received The surplus data is stored in the surplus data storage means, and the surplus amount at the certain time included in the latest surplus data is read from the surplus data storage means, and the read additional order required amount and the read latest surplus data are read out. An additional order quantity calculation step for calculating an additional order quantity as an actual quantity to be ordered among the additional order requirement quantities based on the competence capacity:
[Selection] Figure 1

Description

  The present invention relates to an order timing and a material order quantity determination system, a material order quantity determination program and a material order quantity determination method for supporting the order quantity when ordering materials according to a production plan and a material requirement plan.

In production activities where a production plan is made according to demand, materials are purchased from production sites (hereinafter referred to as suppliers) from outside or other factories, and the company manufactures its own products, a material ordering instruction method, especially a method for calculating the order timing There are the following methods (1) and (2).
(1) Create a material requirements plan from the production plan using MRP (Material Requirement Planning), and consider the material production lead time and safety stock amount at the supplier, and a certain period from the material usage time in the production plan Place an order before.
(2) Using the Kanban method, place an order with the supplier to replenish the used amount when the material is used so as to maintain a safe stock amount.

  In general, the production plan includes the demand forecast for the products produced by the company or its own factory, the order from the customer for the products, the capacity of the company's own resources such as the production facilities and production personnel of the company or its own factory for producing the product, Created by SCP (Supply Chain Planning), etc., based on the usage plan assigned to resources and the delivery plan for materials delivered from other companies or other factories. Further, a material requirement plan is created by MRP or the like according to the production plan, and a material order specifying a desired delivery date and a desired delivery quantity (order quantity) is issued to the supplier who delivers the material.

  In production planning, demand forecasts generally become accurate with the passage of time, so production plans and material requirement plans created based on the demand forecast also become accurate with the passage of time. For this reason, from the viewpoint of reducing the stock and stock of materials, it is desirable to place orders for materials as close to the use time of the materials as possible.

  In addition, if the supplier does not have inventory of the material, the supplier cannot deliver the material in a period shorter than the production lead time of the material, so if the material order is too late, the necessary amount of material will be delivered at the time of use. There is a risk of delivery cracking. For this reason, it is desirable to place an order at the time when the production lead time is traced back from the use time of the material, but the production lead time varies depending on the situation of the production plan of the supplier and does not take a constant value. For example, during the prosperous period for suppliers and when the production facilities and production personnel of suppliers are decreasing, the lead time for manufacturing materials at suppliers is long.

  Under such circumstances, the method (1) described above does not know when and how much materials can be delivered to the company from the supplier, and therefore the supplier is engaged in manufacturing materials for other companies. If the manufacturing lead time is too short, the material ordering instruction is too late and the delivery of the material may not be in time. On the other hand, if the production lead time is predicted too long, the material requirement plan changes due to fluctuations in demand, the order quantity and the required quantity at the time of ordering shift, and stagnant stock or dying stock occurs.

  In the method (2), the number of kanbans is determined on the premise that the stock has a certain amount of stock so as not to cause inventory breakage. Therefore, if the demand fluctuation is large, it is necessary to increase the number of kanbans. May hold in stock.

As described above, in the conventional technology, there is no method for suppressing the stock amount of materials by bringing the material ordering time as close as possible to the usage time as long as the material delivery is not delayed.
JP 2003-223547 A

  The present invention provides a material order quantity determination system, a material order quantity determination program, and a material order quantity determination method that can suppress the occurrence of surplus inventory of materials due to a shift in demand prediction while preventing breakage of material orders.

  The material order quantity calculation system according to one aspect of the present invention includes a time when the material used for manufacturing the product is used for the additional order requirement amount that is a quantity that has to be delivered from the supplier but has not yet been ordered. Additional order required quantity storage means stored in association with: A surplus data receiving means for receiving, in a time series, surplus data representing a surplus quantity as a quantity that can be supplied by the supplier in association with the time period And: surplus data storing means for storing surplus data received by the receiving means; reading the additional order requirement quantity at a certain time from the additional order requirement quantity storage means, and the certain time period included in the latest surplus data Is read from the remaining power data storage means, and the read additional order required amount, the read latest remaining power amount, Based on the additional order quantity calculating means for calculating the additional amount of orders as an amount to be actually ordered among said read reorder required amount: comprising a.

  The material order quantity calculation program as one aspect of the present invention is the time when the material is used for the additional order requirement amount, which is a quantity that needs to be delivered from the supplier but has not yet been ordered for the material used for manufacturing the product. A step of reading the additional order requirement quantity stored in association with the additional order requirement quantity storage means; and a surplus data representing the quantity of surplus as a quantity that the supplier can supply the material in association with the period. A surplus data receiving step for receiving a plurality of times in time series: a storing step for storing the received surplus data in a surplus data storage means; and a certain period of time included in the latest surplus data from the surplus data storage means A reading step of reading out the surplus energy amount at: the read out additional order requirement amount, the read out latest surplus energy amount, Based on the additional order quantity calculating step of calculating the additional amount of orders as an amount to be actually ordered out of the reorder required amount: causing the computer to execute.

  The material order quantity calculation method according to one aspect of the present invention includes a time when the material is used for an additional order requirement amount that is a quantity that is required to be delivered from a supplier but not yet ordered for a material used for manufacturing a product. A step of reading the additional order requirement quantity stored in association with the additional order requirement quantity storage means; and a surplus data representing the quantity of surplus as a quantity that the supplier can supply the material in association with the period. A surplus data receiving step for receiving a plurality of times in time series: a storing step for storing the received surplus data in a surplus data storage means; and a certain period of time included in the latest surplus data from the surplus data storage means A reading step of reading out the surplus power amount at the time: based on the read out additional order requirement amount and the read out latest surplus power amount. Te, an additional order quantity calculating step of calculating the additional amount of orders as an amount to be actually ordered out of the reorder required amount: the computer executes.

  According to the present invention, it is possible to suppress the occurrence of surplus inventory of materials due to a shift in demand prediction while preventing breakage of material orders.

  FIG. 1 is a block diagram showing a configuration of a material order quantity determination system 11 as an embodiment of the present invention.

  A production plan is created by SCP (Supply Chain Planning) or the like, and a material requirement plan is created by MRP (Material Requirement Planning) or the like based on the produced production plan. The material requirement acquisition unit 12 acquires the material requirement plan from the storage unit or the like. An example of the material requirement plan is shown in FIG. The material requirement plan includes, for each period of each material, an inventory transfer amount from the previous period, a scheduled delivery amount from the supplier at that period, an additional order requirement amount, a required amount, and an inventory carry-forward amount to the later period.

  The order data holding unit 13 holds order data. An example of ordering data is shown in FIG. The ordering data includes a required amount for each material, an already ordered amount, an additional order requirement amount, and an additional order amount.

  The required amount and the additional order required amount in the order data are obtained from the material requirement plan. The already ordered quantity is obtained from delivery schedule data described later. Note that the already ordered quantity matches the planned delivery quantity in the material requirement plan. The additional order quantity is calculated by the order instruction creating means 14 from the amount of remaining material and the additional order requirement quantity which will be described later.

  The ordering instruction transmission means 16 uses the ordering data to create material additional ordering data including an additional ordering quantity for each material period, and transmits the material additional ordering data to the supplier's device via, for example, a network. An example of the material additional ordering data is shown in FIG.

  Based on the material additional ordering data received at the company's own device, the supplier creates delivery schedule data including the delivery amount for each material period, and sends the created delivery schedule data from the company's device to the system 11, such as a network. To send through. An example of delivery schedule data is shown in FIG. The delivery schedule data is a response from the supplier to the material additional ordering data transmitted from the company or own factory, and consists of the scheduled delivery quantity for each material period.

  Further, the supplier creates surplus time series data indicating the amount of surplus capacity of each material in each period, and transmits the created surplus time series data to the system 11 via, for example, a network. An example of the remaining time series data is shown in FIG. The remaining capacity is calculated at the supplier who delivers the material. The surplus capacity indicates the quantity of materials that can be delivered from the supplier to the company or to its own factory in each period, other than the shipment quantity already recorded in the production plan quantity of the supplier. The surplus time series data is received in time series over a plurality of times.

  The delivery schedule receiving means 15 receives delivery schedule data from the supplier's device, and updates the already ordered quantity in the ordering data using the received delivery schedule data.

  The surplus power time-series data receiving means 19 receives the surplus power time-series data from the supplier device, and stores the received surplus time-series data in the surplus power time-series data holding means 17. The remaining power time-series data holding means 17 stores the remaining power time-series data in a state where the reception order is held.

  The ordering instruction creating means 14 uses the calculation method described later from the additional ordering requirement amount at each time in the ordering data and the material surplus amount at each time in the remaining power time series data (for example, the latest one). The additional order quantity (material additional order data) is calculated. The additional order quantity represents the quantity that should actually be additionally ordered among the additional order requirement quantities. In calculating the additional order quantity, the values of various parameters held in the parameter holding means 18 are used. The order instruction creating means 14 updates the additional order quantity at each time in the order data using the calculated additional order quantity.

  Hereinafter, a method in which the order instruction creating unit 14 calculates the additional order quantity will be described in detail.

  First, the basic concept of calculating the additional order quantity will be described.

  If the supplier's surplus capacity is sufficiently large compared to the additional order requirement, the order will not be placed at this time. Is less likely to occur. On the other hand, when the time has passed and it is almost time to use the material, the time that can be secured for manufacturing the material at the supplier will decrease, orders for the material from other companies and orders for other materials may occur, There is a possibility that the remaining capacity at the time of use of the material becomes small. Thus, it is conceivable to prevent cracks in the delivery of the material by placing an order for part or all of the additional order requirement.

  In other words, while looking at the time-series data of the remaining capacity of materials from the supplier, when the remaining capacity is sufficiently larger than the additional order required quantity, even if there is an additional order required quantity, it will not be ordered. Order a part of the required quantity. In other words, the material ordering time is brought closer to the material use time by delaying the material ordering time as much as possible while keeping the amount of remaining capacity for the additional ordering requirement amount above a certain level. Accordingly, it is possible to suppress the occurrence of surplus stock of materials due to a shift in demand prediction while preventing breakage of material orders.

Hereinafter, as an example, three methods for calculating the additional order quantity will be described.
(Additional order quantity calculation method 1)
In the material ordering data, the additional ordering requirement amount of the material m at time k is x _m (k), and the remaining capacity of the material in the same period in the remaining power time-series data is y _m (k). Further, the additional order quantity to be ordered at the present time out of the additional order requirement quantity x _m (k) is z _m (k). Also the ratio x _m (k) of y _m (k) and s _m (k). The ratio of x _m (k) to y _m (k) may be s _m (k).

If s _m (k) is equal to or greater than the threshold value α, it is determined that the remaining power is sufficiently larger than the additional order required amount, and no additional material ordering is performed. When s _m (k) is smaller than the threshold value α, the amount of remaining power with respect to the additional order required amount is kept at α or more by performing the additional material ordering. However, α ≧ 1. Hereinafter, a method of calculating the additional order quantity when _sm (k) <α will be described.

と見積もることができる。 If the reorder required amount after adding ordered z _m (k) of the additional order necessary amount x _m (k) and x _'m (k),

Can be estimated.

と見積もることができる。 In addition, if z _m (k) is additionally ordered out of the additional order required quantity x _m (k), y ' _m (k)

Can be estimated.

と見積もることができる。 Therefore, the ratio of z _m 'surplus amount of estimate for _m (k) y' estimate of additional orders required amount after adding ordered (k) x _m (k) of the additional order necessary amount x _m (k) s' _m (k)

Can be estimated.

となるようにt_m(k)を決定し、さらに（式５）よりz_m(k)＝t_m(k)x_m(k)として追加発注すると、（式６）は次式

と同値であるので、追加発注した後の追加発注必要量の見積もりx'_m(k)に対する余力量の見積もりy'_m(k)の比s'_m(k)を閾値α以上にすることができる。 At this time, the ratio of the additional order requirement quantity x _m (k) and the additional order quantity z _m (k) is t _m (k).

T _m (k) is determined so that the following expression is satisfied, and when an additional order is made from (Equation 5) as z _m (k) = t _m (k) x _m (k), (Equation 6)

Therefore, the ratio s' _m (k) of the surplus capacity estimate y ' _m (k) to the extra order requirement estimate x' _m (k) after the additional order must be greater than or equal to the threshold value α. it can.

  Thereafter, if the surplus capacity decreases in the supplier with respect to the additional order due to, for example, renewal of the production plan or the passage of time, and the ratio of the surplus capacity to the additional order required quantity becomes smaller than the threshold value α, the same as described above. Calculate the additional order quantity and place an additional order.

のように変更すると、（式６）は次式のように変更される。

(Additional order quantity calculation method 2)
Estimate the amount of remaining power after additional ordering of z _m (k) out of the additional order required quantity x _m (k) from the following formula:

(Expression 6) is changed to the following expression.

と同値であるので、追加発注した後の追加発注必要量の見積もりx'_m(k)に対する余力量の見積もりy'_m(k)の比s'_m(k)を閾値α以上にすることができる。 When t _m (k) is determined so as to satisfy (Equation 9) and an additional order is made from (Equation 5) as z _m (k) = t _m (k) x _m (k), (Equation 9) becomes ( Based on the estimate of Equation 8)

Therefore, the ratio s' _m (k) of the surplus capacity estimate y ' _m (k) to the extra order requirement estimate x' _m (k) after the additional order must be greater than or equal to the threshold value α. it can.

(Additional order quantity calculation method 3)
When the remaining capacity of the material is changed in accordance with a change in the production plan of the supplier, the updated remaining time series data is transmitted from the supplier to the company or own factory.

At this time, out of the additional order required quantity x _m (k), the estimated remaining capacity y ' _m (k) after additional ordering of z _m (k) is included, including the change in remaining capacity over time By making an estimate, it is possible to place an additional order while accurately following the change in the remaining capacity.

とし、追加発注を行わない場合のs_m(k,n+1)を次式のように見積もる。

そしてs_m(k,n+1)≧αなら追加発注を行わず、s_m(k,n+1)＜αなら以下のように追加発注を行う。 The remaining capacity of materials with time k is y _m (k, 1), y _m (k, 2) ..., y _m (k, n) (where n is the number of times the remaining time series data is received from the supplier) Suppose that it has changed. At this time,

And s _m (k, n + 1) when no additional order is placed is estimated as follows:

If s _m (k, n + 1) ≧ α, no additional order is made, and if s _m (k, n + 1) <α, an additional order is made as follows.

のように、z_m(k)を追加発注した後の余力量のｎ＋１回目の報告y'_m(k,n+1)を見積もる。ここでΔy_m(k,n)はサプライヤから受信したｎ−１回目の余力時系列データからｎ回目の余力時系列データにわたる、時期ｋの資材ｍの余力減少量である。このとき

となるようにt_m(k)を決定し、さらに（式５）よりz_m(k)＝t_m(k)x_m(k)として追加発注すると、（式１６）は次式

と同値であるので、追加発注した後の追加発注必要量の見積もりx'_m(k)に対する余力量の見積もりy'_m(k,n+1)の比s'_m(k)を、時期ｋの余力量の変化を考慮した上で、閾値α以上にすることができる。 In consideration of the change in the remaining power in the estimation of the remaining power amount of (Expression 3), for example, the following expression

As described above, the n + 1-th report y ′ _m (k, n + 1) of the remaining capacity after additional ordering of z _m (k) is estimated. Here, Δy _m (k, n) is a reduction amount of the remaining power of the material m at the time k ranging from the (n−1) th remaining power time series data to the nth remaining power time series data received from the supplier. At this time

T _m (k) is determined so that the following expression is satisfied, and when an additional order is made from (Equation 5) as z _m (k) = t _m (k) x _m (k), (Equation 16)

Therefore, the ratio s' _m (k) of the surplus capacity estimate y ' _m (k, n + 1) to the additional order requirement estimate x' _m (k) after the additional order is placed Taking into account the change in the amount of remaining power, the threshold value α can be set.

  Hereinafter, a specific example of calculating the additional order quantity using the additional order quantity calculation method 3 will be described.

  FIG. 7 shows ordering data for the time 1 of the material M1. FIG. 8 shows the remaining power time series data for the material M1 received from the supplier three times.

であり閾値α以上なので、ｎ−１回目の時点では追加発注は行わない。ｎ回目の時点でのs_M1(1,n+1)の見積もりは

で閾値より小さくなるので、以下のようにして追加発注を行う。 As can be understood from FIG. 8, the change in the remaining capacity of the material M1 for the period 1 is
{y _M1 (1, n-2), y _M1 (1, n-1), y _M1 (1, n)} = {130.0,125.0,120.0}
It is. Here, the threshold α is set to 2.0, and s _M1 (1, n) at the time point of the (n−1) th time is estimated according to (Expression 14) using the remaining power time series data at the (n−1) th time and the (n−2) th time. When,

Since it is equal to or greater than the threshold value α, no additional order is placed at the (n-1) th time point. The estimate of s _M1 (1, n + 1) at the nth time is

Since it becomes smaller than the threshold value, an additional order is made as follows.

を満たす必要がある。ここではt_M1(1)＝0.08333...に決定すると、（式５）にしたがって

と追加発注量が算出される。 From (Equation 16), t _M1 (1) is

It is necessary to satisfy. Here, t _M1 (1) = 0.08333 ...

And the additional order quantity is calculated.

余力量の見積もりは（式１５）より

これより追加発注後における追加発注必要量の見積もりに対する余力量の見積もりは（式１７）より

となり、余力量の変化のもとで追加発注を行うことにより追加発注必要量の見積もりに対する余力量の見積もりの比を閾値α以上に保つことができる。 At this time, the estimate of the additional order requirement after the additional order is from (Formula 2)

Estimated remaining capacity from (Equation 15)

From this, the estimate of the remaining capacity for the estimate of the additional order requirement after the additional order is obtained from (Equation 17)

Thus, by performing an additional order under the change in the surplus capacity, the ratio of the surplus capacity estimate to the estimate of the additional order requirement quantity can be kept above the threshold value α.

  As a result, the order data is updated as shown in FIG.

  The ordering instruction transmitting means 16 creates material additional ordering data shown in FIG. 10 based on the ordering data in FIG. 9 and transmits it to the supplier.

  Assume that the supplier transmits delivery schedule data shown in FIG. 11 as a response to the material additional ordering data.

  The delivery schedule receiving means 15 receives this delivery schedule data, and updates the existing order quantity, additional order requirement quantity, and additional order quantity in the order data as shown in FIG.

  As described above, according to the present embodiment, for each period of each material, in the material requirement plan, out of the quantity of materials that need to be delivered but have not yet been ordered from the supplier (additional order required amount) In order to determine how many quantities should actually be ordered at the present time based on the remaining time series data received from the supplier and the additional order requirement, delay the order for the additional order requirement of the material as much as possible. It is possible to approach the time of use of the material.

  In other words, while comparing the time series data of the materials from the supplier and the additional order required amount, when the remaining capacity amount is larger than the additional order required amount, even if there is an additional order required amount, the order is not placed and the remaining capacity amount is small. By ordering a part of the additional order requirement as it becomes, the amount of remaining capacity for the additional order requirement is kept above a certain level. In this way, by delaying the material ordering time as much as possible and approaching the use time of the material, it is possible to prevent the occurrence of surplus stock of the material due to a shift in demand prediction while preventing the cracking of the material ordering.

It is a block diagram which shows the structure of the material order quantity determination system as one embodiment of this invention. An example of a material requirement plan is shown. An example of order data is shown. An example of delivery schedule data is shown. An example of surplus time series data is shown. An example of material additional order data is shown. The order data for time 1 of material M1 is shown. The remaining power time series data for the material M1 received from the supplier is shown. The order data updated from the state of FIG. 7 is shown. The material additional order data produced based on the order data of FIG. 9 are shown. The delivery schedule data which the supplier responded with respect to the material additional order data of FIG. 10 are shown. The order data updated from the state of FIG. 9 is shown.

Explanation of symbols

11 Material order quantity determination system 12 Material requirement plan acquisition means 13 Order data holding means 14 Order instruction creation means 15 Delivery schedule reception means 16 Order instruction transmission means 17 Remaining power time series data holding means 18 Parameter holding means 19 Remaining power time series data reception means

Claims (13)

An additional order required quantity storage means for storing an additional order required quantity, which is a quantity that needs to be delivered from a supplier but has not yet been ordered, for a material used for manufacturing a product in association with a time when the material is used:
Surplus data receiving means for receiving, in a time series, surplus data representing a surplus amount as a quantity that can be supplied by the supplier in association with the time period:
Surplus data storage means for storing surplus data received by the receiving means:
The additional order required amount at a certain time is read from the additional order required amount storing means, the remaining power amount at the certain time included in the latest remaining power data is read from the remaining power data storing means, and the read additional order required amount And an additional order quantity calculation means for calculating an additional order quantity as an actual quantity to be ordered out of the read additional order requirement quantity based on the read latest remaining capacity quantity:
Material order quantity calculation system with A parameter storage means for storing the parameter value α;
The additional order quantity calculation means includes:
Calculating a ratio value S of the latest reserve capacity to the additional order requirement or vice versa;
When the ratio value S does not satisfy the criterion based on the parameter value α, it is determined that the additional order for the material should be performed, the additional order quantity is calculated, and when the criterion based on the parameter value α is satisfied, The material order quantity calculation system according to claim 1, wherein it is determined that it is not necessary to place an additional order. The additional order quantity calculation means includes:
When it is determined that an additional order for the material should be made,
X is the amount of additional order required at a certain time.
Y is the latest available capacity at a certain time.
The additional order quantity is Z,
Of the additional order requirement quantity X, an estimate of the additional order requirement quantity after the additional order of Z is given as X ′ = X−Z,
Y ′ = Y−Z, which is an estimate of the amount of remaining power after the additional order for the additional order required quantity X is made.
3. The material according to claim 2, wherein the value of Z is determined so that a ratio value S ′ of Y ′ with respect to X ′ or vice versa satisfies a criterion based on the parameter value α. Order quantity calculation system. The parameter storage means further stores a parameter value β,
The additional order quantity calculation means includes:
When it is determined that the additional order should be made,
X is the amount of additional order required at a certain time.
Y is the latest available capacity at a certain time.
The additional order quantity is Z,
Of the additional order requirement quantity X, an estimate of the additional order requirement quantity after the additional order of Z is given as X ′ = X−Z,
Y ′ = Y−βZ, which is an estimate of the amount of remaining power after the additional order of the additional order required quantity X is ordered.
3. The material according to claim 2, wherein the value of Z is determined so that a ratio value S ′ of Y ′ with respect to X ′ or vice versa satisfies a criterion based on the parameter value α. Order quantity calculation system. A parameter storage means for storing the parameter value α;
The additional order quantity calculation means includes:
X is the amount of additional order required at a certain time.
Y (n), the amount of remaining power at the certain time of the latest remaining power data received for the nth time,
The ratio value of Y (n) to X or vice versa is S (n),
The change in the amount of remaining power Y (na) -Y (n) (where a ≧ 1) is expressed as ΔY (n),
The ratio value of ΔY (n) to X or vice versa is ΔS (n),
In this case, the ratio value S (n + 1) when it is assumed that no additional order is placed is predicted as S (n) −ΔS (n),
If the S (n + 1) does not satisfy the criterion based on the parameter value α, it is determined that the additional order for the material should be placed, and the additional order quantity is calculated, and the S (n + 1) is the parameter value α. If it meets the criteria of, make a decision that there is no need to place additional orders,
The material order quantity calculation system according to claim 1, wherein: The additional order quantity calculation means includes:
When it is determined that an additional order for the material should be made,
The additional order quantity is Z,
X ′ = X−Z is an estimate of the additional order required amount after additionally ordering Z of the additional order required amount X at the certain time.
Y ′ (n + 1) = Y (n) −ΔY (n) −Z, where Y ′ (n + 1) = Y (n) −ΔY (n) −Z, is an estimate of the remaining power amount at the certain time of the (n + 1) th remaining power data received after the additional order amount Z is additionally ordered.
In this case, the value of Z is calculated so that a ratio value S ′ (n + 1) of Y ′ (n + 1) to X ′ or vice versa satisfies a criterion based on the parameter α. Item 5. The material order quantity calculation system according to Item 5. For materials used for manufacturing products, there is an additional order requirement storage means that stores additional order requirements, which are quantities that need to be delivered from the supplier but have not yet been ordered, in association with the time when the materials are used. The steps to read out the additional order requirements for the time period:
A surplus data receiving step of receiving, in a time series, surplus data representing a surplus amount as a quantity that can be supplied by the supplier in association with the time period;
A storing step of storing the received surplus data in the surplus data storage means;
A step of reading out the remaining power amount at a certain time included in the latest remaining power data from the remaining power data storage means:
An additional order quantity calculation step of calculating an additional order quantity as an actual quantity to be ordered out of the additional order requirement quantities based on the read additional order requirement quantity and the read latest surplus capacity quantity:
Order quantity calculation program to make computer execute. A step of reading the parameter value α from the parameter storage means;
The additional order quantity calculation step includes:
Calculating a ratio value S of the latest reserve capacity to the additional order requirement or vice versa;
When the ratio value S does not satisfy the criterion based on the parameter value α, it is determined that the additional order for the material should be performed, the additional order quantity is calculated, and when the criterion based on the parameter value α is satisfied, A step of determining that it is not necessary to place an additional order;
The material order quantity calculation program according to claim 7, comprising: The additional order quantity calculation step includes:
When it is determined that an additional order for the material should be made,
X is the amount of additional order required at a certain time.
Y is the latest available capacity at a certain time.
The additional order quantity is Z,
Of the additional order requirement quantity X, an estimate of the additional order requirement quantity after the additional order of Z is given as X ′ = X−Z,
Y ′ = Y−Z, which is an estimate of the amount of remaining power after the additional order for the additional order required quantity X is made.
9. The material according to claim 8, wherein the value of Z is determined so that a ratio value S ′ of Y ′ to X ′ or vice versa satisfies a criterion based on the parameter value α. Order quantity calculation program. Further comprising reading the parameter value β from the parameter storage means,
The additional order quantity calculation step includes:
When it is determined that the additional order should be made,
X is the amount of additional order required at a certain time.
Y is the latest available capacity at a certain time.
The additional order quantity is Z,
Of the additional order requirement quantity X, an estimate of the additional order requirement quantity after the additional order of Z is given as X ′ = X−Z,
Y ′ = Y−βZ, which is an estimate of the amount of remaining power after the additional order of the additional order required quantity X is ordered.
9. The material according to claim 8, wherein the value of Z is determined so that a ratio value S ′ of Y ′ to X ′ or vice versa satisfies a criterion based on the parameter value α. Order quantity calculation program. A step of reading the parameter value α from the parameter storage means;
The additional order quantity calculation step includes:
X is the amount of additional order required at a certain time.
Y (n), the amount of remaining power at the certain time in the latest remaining power data received for the nth time,
The ratio value of Y (n) to X or vice versa is S (n),
The change in the amount of remaining power Y (na) -Y (n) (where a ≧ 1) is expressed as ΔY (n),
The ratio value of ΔY (n) to X or vice versa is ΔS (n),
In this case, the ratio value S (n + 1) in the case where it is assumed that no additional order is placed is predicted and calculated as S (n) −ΔS (n),
If the S (n + 1) does not satisfy the criterion based on the parameter value α, it is determined that the additional order for the material should be placed, and the additional order quantity is calculated, and the S (n + 1) is the parameter value α. If it meets the criteria of, make a decision that there is no need to place additional orders,
The material order quantity calculation program according to claim 7 characterized by things. The additional order quantity calculation step includes:
When it is determined that an additional order for the material should be made,
The additional order quantity is Z,
X ′ = X−Z is an estimate of the additional order required amount after additionally ordering Z of the additional order required amount X at the certain time.
Y ′ (n + 1) = Y (n) −ΔY (n) −Z, where Y ′ (n + 1) = Y (n) −ΔY (n) −Z is an estimate of the remaining power amount at the certain time in the (n + 1) th remaining power data received after the additional order amount Z is additionally ordered.
In this case, the value of Z is calculated so that a ratio value S ′ (n + 1) of Y ′ (n + 1) to X ′ or vice versa satisfies a criterion based on the parameter α. Item 11. A material order quantity calculation program according to Item 11. For materials used for manufacturing products, there is an additional order requirement storage means that stores additional order requirements, which are quantities that need to be delivered from the supplier but have not yet been ordered, in association with the time when the materials are used. The steps to read out the additional order requirements for the time period:
A surplus data receiving step of receiving, in a time series, surplus data representing a surplus amount as a quantity that can be supplied by the supplier in association with the time period;
A storing step of storing the received surplus data in the surplus data storage means;
A step of reading out the remaining power amount at a certain time included in the latest remaining power data from the remaining power data storage means:
An additional order quantity calculation step of calculating an additional order quantity as an actual quantity to be ordered out of the additional order requirement quantities based on the read additional order requirement quantity and the read latest surplus capacity quantity:
The material order quantity calculation method executed by the computer.

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