REQUIRED INVENTORY CALCULATING SYSTEM

A required inventory calculating system includes a first section for calculating product importance level coefficients, a second section for calculating procurement risk level coefficients, a third section for calculating general coefficients by multiplying the product importance level coefficients by the procurement risk level coefficients, a fourth section for calculating required inventory periods respectively with respect to raw materials or partly finished products by multiplying the general coefficients by a predetermined longest inventory period, and, if the required inventory periods are shorter than a predetermined shortest inventory period, setting the required inventory periods as the shortest inventory period, and a fifth section for calculating required inventories respectively for the raw materials or the partly finished products by multiplying required quantities of the raw materials or the partly finished products required to supply the products to customers or wholesalers in a predetermined period by the respective required inventory periods.

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to a required inventory calculating system for calculating appropriate required inventories of raw materials or partly finished products to be procured from one or more suppliers and added to a stock of a product supplier amidst commercial activities of the product supplier to procure at least either raw materials or partly finished products from the one or more suppliers, manufacture products therefrom, and supply the products to customers or wholesalers.

Description of the Related Art

Product suppliers such as makers, i.e., product manufacturers, procure raw materials and partly finished products from one or more suppliers, manufacture products from the procured raw materials and partly finished products, and sell the products to customers or wholesalers via logistics providers. While engaging the various operations, the product manufacturers establish links with various firms such as suppliers or logistics providers. The sequence of processes including the procurement of raw materials and partly finished products, the fabrication of products, the inventory management for raw materials and partly finished products, the distribution and sale of products, etc. is referred to as “supply chain.”

For making the supply chain more efficient, it is known at present in the art to perform supply chain management (SCM) using a supply chain model established on a computer (see, for example, JP 2009-75919A). However, even though the SCM allows a product supplier to manage the number of products to be manufactured, the delivery dates thereof, the inventory of raw materials and partly finished products, and other data appropriately at normal times, the supply chain between the suppliers and the product suppliers may be disrupted in emergency situations such as earthquakes and floods that are difficult to quantify in terms of frequency of occurrence and unable to control deliberately.

Product suppliers are required to manage the inventory of raw materials and partly finished products appropriately, for example, in order to supply products stably to customers or wholesalers not only at ordinary times but also in case of emergency. However, if product suppliers manufacture a wide range of products and deal with many domestic and overseas suppliers, then it is not easy to decide which raw materials and partly finished products for which products are to be kept preferentially in inventory.

Specifically, it is difficult to decide, with respect to suppliers in various countries of the world, which raw materials and partly finished products for which products are to be kept preferentially in inventory and how much the stock of raw materials and partly finished products is to be adjusted in view of the laws, state of affairs, geographical risks, etc. in the countries in case of emergency. In addition, when workers of product suppliers are to determine the inventory of raw materials and partly finished products required to manufacture each product, the workers need to spend an enormous number of man-hours, i.e., a working time multiplied by the number of persons working to determine the inventory, resulting in a costly process.

SUMMARY OF THE INVENTION

The present invention has been made in view of the above problems. It is an object of the present invention to provide a required inventory calculating system for calculating a required inventory of raw materials, etc. required by a product supplier for stably supplying products, less costly in a smaller number of man-hours than if a worker determines the inventory.

In accordance with an aspect of the present invention, there is provided a required inventory calculating system for calculating appropriate required inventories of raw materials or partly finished products to be procured from one or more suppliers and added to stock of a product supplier amidst commercial activities of the product supplier to procure at least either the raw materials or the partly finished products from the one or more suppliers, manufacture products therefrom, and supply the products to customers or wholesalers. The required inventory calculating system includes a memory storing names of the products, names of the raw materials or the partly finished products from which the products are manufactured, names of the one or more suppliers that supply the raw materials or the partly finished products, and required quantities of the raw materials or the partly finished products required to supply the products to the customers or the wholesalers in a predetermined period. The required inventory calculating system further includes a processor, a product importance level coefficient calculating section for calculating product importance level coefficients established depending on an extent to which the products are needed by the customers or the wholesalers and representing respective levels of importance of the products, a procurement risk level coefficient calculating section for calculating procurement risk level coefficients, respectively with respect to the raw materials or the partly finished products, established depending on a risk that the product supplier may not be able to procure the raw materials or the partly finished products from the one or more suppliers and representing the respective levels of procurement risk of the raw materials or the partly finished products, a general coefficient calculating section for calculating general coefficients normalized such that their maximum value is 1 by multiplying the product importance level coefficients by the procurement risk level coefficients respectively with respect to the raw materials or the partly finished products, a required inventory period calculating section for calculating required inventory periods respectively with respect to the raw materials or the partly finished products by multiplying the general coefficients by a predetermined longest inventory period, and, if the calculated required inventory periods are shorter than a predetermined shortest inventory period, setting the calculated required inventory periods as the shortest inventory period, and a required inventory calculating section for calculating required inventories respectively for the raw materials or the partly finished products by multiplying the required quantities of the raw materials or the partly finished products in the predetermined period by the respective calculated required inventory periods.

Preferably, the product importance level coefficients are established such that the larger the quantities sold of the products in the predetermined period are, the higher numerical values represented by the product importance level coefficients are.

Preferably, the product importance level coefficients include actual price coefficients, and the actual price coefficients are established such that the higher an average value of actual prices of the products in the predetermined period is or the lower a discount ratio of the actual prices is, the higher the actual price coefficients are.

Preferably, the procurement risk level coefficients are calculated depending on risks of natural disasters at locations of places where the suppliers manufacture the raw materials or the partly finished products or places where the suppliers store the raw materials or the partly finished products.

Preferably, the procurement risk level coefficients are calculated in view of geographical factors of the suppliers including world risk indexes of a world risk report about countries of places where the suppliers manufacture the raw materials or the partly finished products or places where the suppliers store the raw materials or the partly finished products and information as to whether or not there is a nuclear power plant in the locations of the places where the suppliers manufacture the raw materials or the partly finished products or places where the suppliers store the raw materials or the partly finished products.

In accordance with another aspect of the present invention, there is provided a program stored in a medium readable by a computer for enabling the computer, in calculating appropriate required inventories of raw materials or partly finished products to be procured from one or more suppliers and added to stock of a product supplier amidst commercial activities of the product supplier to procure at least either the raw materials or the partly finished products from the one or more suppliers, manufacture products therefrom, and supply the products to customers or wholesalers. The program includes calculating product importance level coefficients established depending on an extent to which the products are needed by the customers or the wholesalers and representing respective levels of importance of the products, calculating procurement risk level coefficients, respectively with respect to the raw materials or the partly finished products, established depending on a risk that the product supplier may not be able to procure the raw materials or the partly finished products from the one or more suppliers and representing the respective levels of procurement risk of the raw materials or the partly finished products, calculating general coefficients normalized such that their maximum value is 1 by multiplying the product importance level coefficients by the procurement risk level coefficients respectively with respect to the raw materials or the partly finished products, calculating required inventory periods respectively with respect to the raw materials or the partly finished products by multiplying the general coefficients by a predetermined longest inventory period, and, if the calculated required inventory periods are shorter than a predetermined shortest inventory period, setting the calculated required inventory periods as the shortest inventory period, and calculating required inventories respectively for the raw materials or the partly finished products by multiplying the required quantities of the raw materials or the partly finished products in the predetermined period by the respective calculated required inventory periods.

Since the required inventory calculating system according to the aspect of the present invention automatically calculates required inventories of raw materials or partly finished products in a predetermined period, the required inventories that are required by a product supplier in the predetermined period to supply products stably can be calculated with a smaller number of man-hours than if they are determined by a worker of the product supplier. Therefore, the required inventories of the raw materials or the partly finished products can be calculated less costly than if they are determined by a worker of the product supplier. Similarly, since the program according to the aspect of the present invention enables the computer to automatically calculate required inventories, the program allows the required inventories to be calculated in smaller number of man-hours and less costly than if they are determined by a worker of the product supplier.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Preferred embodiments of the present invention will be described hereinbelow with reference to the accompanying drawings.FIG.1illustrates in block form a required inventory calculating system2according to a first embodiment of the present invention. As illustrated inFIG.1, the required inventory calculating system2is configured in a stand-alone computer4that is not connected to other computers through a network. The computer4with the required inventory calculating system2configured therein includes a desktop or laptop computer, i.e., a personal computer, or a server. However, as described later, the required inventory calculating system2may be downloaded to the computer4in the form of software as a service (SaaS) from a server via the Internet.

The computer4includes a processor, i.e., a processing device, not depicted, typically a central processing unit (CPU), and a memory, i.e., storage device,6, for example. The memory6includes a main storage unit such as a dynamic random access memory (DRAM), a static random access memory (SRAM), or a read only memory (ROM), and an auxiliary storage unit such as a flash memory, a hard disk drive, or a solid state drive. The auxiliary storage unit stores software including predetermined programs. When the processing device, etc. are operated according to the software, the required inventory calculating system2has its functions performed.

As illustrated inFIG.1, an input device8that acts as an interface to be used by a worker of a product supplier14(seeFIG.2) to enter information into the computer4is electrically connected to the computer4. The input device8preferably, but not necessarily, include a keyboard, a mouse, or a reader for a recording medium, for example. The recording medium includes a universal serial bus (USB) memory or a digital versatile disc (DVD), for example, though it is not limited to such examples, but may be any of other recording mediums.

In addition to the input device8, a display device10is also electrically connected to the computer4. Whereas the input device8is used to enter information into the computer4, the display device10is used to display the results of processing operations performed by the computer4. The display device10may include a touch panel having the function of the input device8. In case the display device10includes a touch panel, the input device8may be dispensed with.

Part of the memory6, e.g., part of the auxiliary storage unit, has a first area16for storing the names of products12(seeFIG.2), i.e., product names16a(seeFIG.4, for example). The products12and other details will be described below with reference toFIG.2.FIG.2illustrates in block form commercial activities of the product supplier14. The product supplier14is a main entity that manufactures products12and sells, i.e., supplies, the products12to a customer18aor a wholesaler18b, and is also called “maker” or “product manufacturer.”

According to the present embodiment, the product supplier14is a judicial person. In the present description, a natural person such as an employer or an employee of the product supplier14as the judicial person is referred to as a “worker.” The product supplier14procures at least either raw materials22or partly finished products24from one or more suppliers20, and manufactures products12therefrom. For example, the product supplier14procures a raw material22afrom a supplier20a, a raw material22bfrom a supplier20b, a partly finished product24afrom a supplier20c, and a partly finisher product24bfrom a supplier20d, and manufactures a product12a. However, the product supplier14may procure the raw material22afrom the supplier20aand manufacture another product12b, or may procure the partly finished product24afrom the supplier20cand manufacture another product12c.

The examples illustrated inFIG.2are simple for illustrative purposes. According to other examples, the product supplier14may procure the raw materials22aand22bfrom the supplier20aand may procure the partly finished products24aand24bfrom the supplier20a. The product supplier14may procure the raw material22aand the partly finished product24afrom the supplier20a. One of the products12includes a hub blade (seeFIG.3), for example. The hub blade has an annular base, i.e., a hub, made of aluminum alloy and an annular cutting edge fixed to an outer circumferential portion of one surface of the base.

FIG.3illustrates an example of correlation between the products12, the raw materials22, and the partly finished products24. The hub blade is fabricated from first abrasive grains and a first bonding material that make up the cutting edge, and the first base, for example. To manufacture the hub blade, any of other raw materials22or partly finished products24may additionally be used. Another one of the products12includes a hubless blade, also called “washer blade,” for example. The hubless blade is free of a base and includes an annular cutting edge only. The hubless blade is fabricated from second abrasive grains and a second bonding material, for example. To manufacture the hubless blade, any of other raw materials22or partly finished products24may additionally be used.

Still another one of the products12includes a grinding wheel, for example. The grinding wheel has an annular third base made of metal and a plurality of grindstones disposed on one surface of the third base and spaced at substantially equal intervals in circumferential directions of the third base. Each of the grindstones is fabricated by mixing third abrasive grains with a third bonding material, molding the mixture, and then sintering the mixture. To manufacture the grinding wheel, any of other raw materials22or partly finished products24may additionally be used.

Yet another one of the products12includes a polishing wheel, for example. The polishing wheel has an annular fourth base made of metal and an annular polishing pad disposed on one surface of the fourth base. To manufacture the polishing wheel, any of other raw materials22or partly finished products24may additionally be used. A still further one of the products12includes a dresser board also called “dressing board.” The dresser board is manufactured by mixing fifth abrasive grains with a fifth bonding material, molding the mixture, and then sintering the mixture, for example. To manufacture the dresser board, any of other raw materials22or partly finished products24may additionally be used.

Processing tools such as hub blades, hubless blades, grinding wheels, or polishing wheels, and dresser boards are expendables used in a semiconductor fabrication apparatus such as a cutting apparatus, a grinding apparatus, or a polishing apparatus. If supply chains for supplying such expendables for use in the semiconductor fabrication apparatus from product suppliers14to customers18aor wholesalers18bare disrupted, then the fabrication of semiconductor chips is adversely affected, resulting in a global delay in the fabrication and distribution of various commercial products including mobile phones, personal computers, automobiles, etc.

According to the present embodiment, the supply of products12is managed using the required inventory calculating system2amidst commercial activities of the product supplier14in the supply chains from the procurement to sale of the products12. Specifically, appropriate required inventories58a(seeFIG.11) of raw materials22and partly finished products24in the product supplier14are calculated using the required inventory calculating system2.

As illustrated inFIG.1, the memory6has a second area26. The second area26stores the names of raw materials22or partly finished products24, i.e., raw material or partly finished product names26a, to be used in the products12. The memory6further has a third area28. The third area28stores the names of one or more suppliers20, i.e., one or more supplier names28a, that supply raw materials22or partly finished products24.

The memory6also includes a fourth area30. The fourth area30stores required quantities30a(seeFIG.11) of raw materials22or partly finished products24required to supply products12to customers18aor wholesalers18bin a predetermined period, i.e., one month according to the present embodiment. The required quantities30aof at least either raw materials22or partly finished products24required to manufacture products12are calculated on the basis of an average value per month of quantities sold of the respective products12in a duration of the last 6 to 12 months prior to the time when the required inventories58aare calculated. Since irregular quantities sold in slack and busy periods can be evened out by using the average value per month of the quantities sold of the products12in the duration of the last 6 to 12 months, the required quantities30aand the required inventories58acan be calculated more adequately than if the average value is not used.

The memory6further includes a fifth area32. The fifth area32stores product importance level coefficients32a. A product importance level coefficient32ais established depending on the extent to which a product12is needed by the customer18aor the wholesaler18b, and represents the level of importance of the product12. The product importance level coefficient32ais calculated by a product importance level coefficient calculating section50.

Product names16aare listed in a leftmost column of the table inFIG.4. InFIG.4, the product names16aare represented by A, B, C, D, and E for illustrative purposes. The names of raw materials22in the raw material or the partly finished product names26arelative to the product names16aare listed in a next column on the right side of the column of the product names16a. The product12of A is associated with four raw materials22, i.e., A-1-1, A-1-2, A-2-1, A-3-1, though other raw materials22and partly finished products24are omitted for illustrative purposes.

The respective products12of B, C, D, and E have in common one kind of the raw materials22, i.e., B-1-1, C-1-1, D-1-1, E-1-1, though other raw materials22and partly finished products24are omitted for illustrative purposes. Numerals following the alphabetical letters represent identification codes for the raw materials22. For example, “1-1” in A-1-1, B1, C-1-1, D-1-1, E-1-1indicate the same raw material22. “1-1” represents abrasive grains having a predetermined level of granularity, for example.

A plurality of suppliers20are listed in a next column on the right side of the column of the raw material names26a. InFIG.4, four different companies represented by a, R, y, and5are listed as the suppliers20.FIG.4depicts that the product supplier14procures the raw materials22indicated by the identification code “1-1” from the three companies a, R, and5, not one company. The sold quantity rankings refer to rankings of average values per month of quantities sold of the respective products12in the duration of the last 6 to 12 months. The product12of A whose sold quantity is the greatest has a ranking1, and the product12of E whose sold quantity is the smallest has a ranking5.

The larger the sold quantity of a product12is, the higher its importance is considered to be, as the product12is more required by customers18aand wholesalers18b. By reflecting a sold quantity coefficient36aof the product12finally in the product importance level coefficient32athereof, the degree of demand for the product12from customers18aand wholesalers18bcan be reflected in the product importance level coefficient32a. The sold quantity coefficient36ais established such that the larger the sold quantity of the product12in a predetermined period is, the higher the numerical value of the sold quantity coefficient36ais. In the example illustrated inFIG.4, since five kinds of products12are illustrated, the sold quantity coefficient36ais defined in five steps. However, the sold quantity coefficient36amay be defined in desired steps depending on the kinds of products12supplied from the product supplier14. For example, if the product supplier14supplies 50 or 100 kinds of products12, then the sold quantity coefficient36amay be defined in 50 or 100 steps.

A discount ratio38arepresents a numerical value indicating the ratio of a desired retail price offered by the product supplier14for a product12and the difference between the desired retail price and the price of the product12actually purchased by a customer18aor a wholesaler18b, i.e., an actual price. InFIG.4, the discount ratios38aare indicated by a percentage. In case a desired retail price is constant for a predetermined period, for example, a discount ratio38ais obtained by dividing the difference between the desired retail price and the actual price by an average value of actual prices of the products12in the predetermined period and then multiplying the quotient by 100. In case the desired retail price varies in the predetermined period, the variation may suitably be reflected in the discount ratio38a.

A discount ratio38ais finally reflected in a product importance level coefficient32a. The lower the discount ratio38aof a product12is, the higher its importance is considered to be, as the product12is more required by customers18aand wholesalers18b. By reflecting the discount ratio38aof the product12finally in the product importance level coefficient32athereof, the degree of demand for the product12from customers18aand wholesalers18bcan be reflected in the product importance level coefficient32a. According to the present embodiment, rankings that are the reverse of the rankings of discount ratios38aare determined to be actual price coefficients40a. Therefore, the actual price coefficient40ais established such that the lower the discount ratio38ais, the higher the actual price coefficient40ais. Stated otherwise, the higher the actual price is, the higher the actual price coefficient40ais.

In the example illustrated inFIG.4, since five kinds of products12are illustrated, the discount ratio38ais defined in five steps. Consequently, the actual price coefficient40ais also defined in five steps. Specifically, the product12of D whose discount ratio38ahas a ranking1has an actual price coefficient40aof5that is the reverse of the ranking1of the discount ratio38a. Similarly, the product12of B whose discount ratio38ahas a ranking5has an actual price coefficient40aof 1 that is the reverse of the ranking5of the discount ratio38a. However, an actual price coefficient40amay be determined appropriately depending on the kinds of products12supplied by the product supplier14. For example, if the product supplier14supplies 50 or 100 kinds of products12, then the actual price coefficient40amay be defined in 50 or 100 steps.

A situation and condition coefficient42arepresents a numerical value set by the worker of the product supplier14depending on the circumstances in which raw materials22and partly finished products24are procured. For example, in case a raw material22is procured from a plurality of suppliers20, since the risk that the raw material22cannot be procured is considered to be relatively low, the situation and condition coefficient42ais set to a relatively small value. By contrast, in case a raw material22is procured from one supplier20only, since the risk that the raw material22cannot be procured is considered to be relatively high, the situation and condition coefficient42ais set to 1.0 (maximum value).

The products12of B and E inFIG.4have respective situation and condition coefficients42aof 1.0 because they are affected by other raw materials22and partly finished products24(not depicted) than the raw material22identified by the identification code “1-1.” However, as the situation and condition coefficients42aare coefficients selectively set in calculating product importance level coefficients32a, the situation and condition coefficients42athemselves may be omitted.

The product of a sold quantity coefficient36a, an actual price coefficient40a, and a situation and condition coefficient42arepresents a coefficient multiplication value44a(S10inFIG.5).FIG.5is a flowchart of a sequence for calculating a product importance level coefficient32a. The coefficient multiplication value44aof the product12of A is 8 (=5×2×0.8), and the coefficient multiplication value44aof the product12of B is 3 (=3×1×1.0). The coefficient multiplication value44aof the product12of C is 6 (=4×3×0.5), and the coefficient multiplication value44aof the product12of D is 7 (=2×5×0.7). The coefficient multiplication value44aof the product12of E is 4 (=1×4×1.0).

According to the present embodiment, a value obtained by dividing a coefficient multiplication value44aby the maximum value of a plurality of coefficient multiplication values44arepresents a product importance level coefficient32a(S12inFIG.5). In the example illustrated inFIG.4, since the maximum coefficient multiplication value44ais “8” with respect to the product12of A, the product importance level coefficients32aof the products12are calculated by dividing the respective coefficient multiplication values44aby “8.” As illustrated inFIG.4, the product importance level coefficients32aof the products12of A through E are calculated as 1.000 (=8/8), 0.375 (=⅜), 0.750 (= 6/8), 0.875 (=⅞), and 0.500 ( 4/8), respectively. In this manner, the product importance level coefficients32anormalized such that their maximum value is 1 are calculated respectively with respect to the products12.

As illustrated inFIG.1, the predetermined programs that are executed by the processor function as the required inventory calculating system2. The required inventory calculating system2has the product importance level coefficient calculating section50. The product importance level coefficient calculating section50is implemented by a first program read from the memory6and executed by the processor, for example. The product importance level coefficient calculating section50calculates product importance level coefficients32ain the above manner based on quantities sold, desired retain prices and actual prices (or discount ratios38a), and situation and condition coefficients42a. The product importance level coefficients32acalculated respectively with respect to the products12are stored in the fifth area32of the memory6.

Procurement risk level coefficients34a(seeFIG.9) will be described below with reference toFIGS.6through10. Procurement risk level coefficients34aare calculated by a procurement risk level coefficient calculating section52illustrated inFIG.1. A procurement risk level coefficient34arepresents a level of risk that a raw material22or a partly finished product24may not be procured, i.e., a procurement risk, when the product supplier14is to procure raw materials22or partly finished products24from the suppliers20. Procurement risk level coefficients34aare established depending on the risk that the product supplier14may not be able to procure raw materials22or partly finished products24from one or more suppliers20, and include internal factors (seeFIG.6) of the suppliers20and geographical factors (seeFIG.7) of the suppliers20.

FIG.6illustrates total numbers of points52aof procurement risks taking internal factors of the suppliers20into account. InFIG.6, product names16aare listed in a leftmost column of the illustrated table, as withFIG.4. Partly finished products24are omitted fromFIG.6for illustrative purposes. Product names16a, raw material names, and supplier names28aare identical to those illustrated inFIG.4. A column on the right side of the column of the supplier names28alists Nos. A column on the right side of the column of the Nos. lists specific contents of the Nos. 1 through 38. InFIG.6, only specific contents of the Nos. 4 through 8 are listed, and other specific contents of the Nos. 1 through 3 and 9 through 38 are omitted from illustration, as indicated by “omitted.”

The specific contents of No. 4 are indicative of whether the raw material22fulfils a self-imposed procurement standard of the product supplier14or not. According to the present embodiment, the self-imposed procurement standard of the product supplier14is a standard as to whether raw materials22procured from the supplier(s)20by the product supplier14have a small environmental footprint or not. The procurement of raw materials22complying with such a standard is called “green procurement.” The specific contents of No. 5 are indicative of whether the raw material22contains conflict minerals or not. The specific contents of No. 6 are indicative of whether the raw material22conflicts with intellectual properties such as patents or not.

The specific contents of No. 7 are indicative of whether there is a concern about continuous sales of the raw material22or not. The specific contents of No. 8 are indicative of whether the production of the raw material22hinges upon a natural person of the supplier(s)20, e.g., the skill, the ability, or the like of a natural person, or not. A column on the right side of the column of the contents lists weights represented by natural numbers ranging from 1 to 10. These weights are assigned numerals such that the higher the possibility that the product supplier14may be unable to procure raw materials22from the suppliers20is, the larger the numerals are.

For example, if the raw material22falls into Nos. 4 and 5, then the product supplier20can never procure the raw material22, and the weight is set to 10. In contrast, if the raw material22falls into No. 6, then since the product supplier20may possibly be able to procure the raw material22by taking out a contract for an amicable settlement, the weight is set to 9 lower than 10. Furthermore, if the raw material22falls into Nos. 7 and 8, then since the product supplier20can procure the raw material22from another supplier20, the weight is set to 8 lower than 9. The numbers of points indicating the weights are reviewed and updated accordingly by a worker of the product supplier14.

A column on the right side of the column of the weights lists levels of risk. The levels of risk represent how high is the possibility that the suppliers20will fall into the contents of Nos. 1 through 38, and are set to three steps represented by numerals 0, 1, and 2 according to the present embodiment. The levels of risk are established when the procurement risk level coefficients34aare calculated, for example.

According to the present embodiment, a worker of the product supplier14determines or assesses the possibility that the suppliers20will fall into the contents of Nos. 1 through 38, on the basis of information supplied from the suppliers20such as answers from the suppliers20to a questionnaire given from the product supplier14to the suppliers20. Specifically, if the possibility is high, e.g., if the possibility is in excess of 50%, then the level of risk is set to 2. If the possibility is neither high nor zero, e.g., if the possibility is higher than 0%, but equal to or lower than 50%, then the level of risk is set to 1. If the possibility is none, i.e., 0%, then the level of risk is set to 0. The product of a weight and a level of risk represents a risk assessment number of points (S20inFIG.10). Risk assessment numbers of points are similarly calculated respectively with respect to Nos. 1 through 38, and total risk assessment numbers of points are calculated respectively with respect to the raw material names. According to the present embodiment, the maximum value of the total numbers of points is preset to 336. The total number of points for A-1-1is 67.

According to the present embodiment, after the total number of points has been divided by 336 with respect to each of the raw material names, the quotient is multiplied by 100, thereby calculating a total number of points52aas converted in a scale of maximum 100 points (S22inFIG.10). In the example illustrated inFIG.6, the total number of points is 19.940 with respect to A-1-1, A-3-1, and C-1-1(the supplier name28ais α). In contrast, the total number of points is 8.929 with respect to A-1-2and E-1-1(the supplier name28ais β). The total number of points is 59.524 with respect to A-2-1(the supplier name28ais γ). The total number of points is 44.643 with respect to B-1-1and D-1-1(the supplier name28ais δ).

FIG.7illustrates total numbers of points52bof procurement risks taking geographical factors of the suppliers20into account. InFIG.7, product names16aare listed in a leftmost column of the illustrated table, as withFIG.4. Partly finished products24are omitted fromFIG.7for illustrative purposes. Product names16a, raw material names, and supplier names28aare identical to those illustrated inFIG.4. Note that the partly finished products24are omitted for convenience. Two columns on the right side of the column of the supplier names28alist countries and locations, respectively, of places where the suppliers20have fabricated raw materials22or partly finished products24, i.e., fabrication places, or places where raw materials22or partly finished products24fabricated by the suppliers20are stored, i.e., “storage places.” Foreign countries other than Japan are simply indicated as overseas in the column of countries and listed in the column of locations.

A column on the right side of the column of the countries and the locations lists WRI of WRR about the countries of the places where the raw materials22or partly finished products24have been fabricated or the places where the raw materials22or partly finished products24are stored. WRR is published every year from 2011 on. For the 2020 edition of WRR, reference should be made to the following link in parentheses. (https://reliefweb.int/sites/reliefweb.int/files/resource s/WorldRiskReport-2020.pdf)

According to WRR, indexes assessing risks such as natural disasters are given as WRI for the respective countries. WRI represents a number of points up to 100. According to the present embodiment, latest WRI at the time total numbers of points52bare calculated are used. A column on the right side of the column of the WRR lists numbers of points as to whether there is a nuclear power plant or not. For example, in case the location of a fabrication place or a storage place is within a circle having a radius of 20 km with a nuclear power plant at its center, 20 points are given. In case the location is not within a circle having a radius of 20 km, but within a circle having a radius of 30 km, 10 points are given. In case the location is outside a circle having a radius of 30 km, no points are given.

The numbers of points as to whether there is a nuclear power plant or not are converted in a scale of maximum 100 points and listed in a column on the right side of the column of the numbers of points as to whether there is a nuclear power plant or not. A column on the right side of the column of the converted numbers of points lists numbers of points depending on risks that earthquakes, floods, landslide disasters, and tsunami, i.e., natural disasters.

Inasmuch as it is difficult to assess natural disasters in other countries than Japan according to a scale used in Japan, only the suppliers20whose fabrication places and storage places, i.e., their locations are in Japan are to be assessed with respect to earthquakes, floods, landslide disasters, and tsunami. Numbers of points about earthquakes, floods, landslide disasters, and tsunami are listed in a scale of maximum 10 points. Numbers of points about earthquakes are calculated using “probability that places will be hit by earthquakes” provided as J-SHIS Map (http://www.j-shis.bosai./go./jp/map/) at J-SHIS (Japan Seismic Hazard Information Station), for example.

According to the present embodiment, the probability that the locations of fabrication places or storage places will be hit by earthquakes having a seismic intensity of a lower6or higher in 30 years to come is converted in a scale of maximum 10 points. For example, the probability ranging from 0% inclusive to 0.1% exclusive is given 1 point, and the probability ranging from 0.1% inclusive to 3% exclusive is given 2 points. In addition, the probability ranging from 3% inclusive to 6% exclusive is given 3 points, the probability ranging from 6% inclusive to 26% exclusive is given 5 points, and the probability of 26% or higher is given 10 points. The probability based on earthquakes having a seismic intensity of a higher6or higher may be used instead of the probability based on earthquakes having a seismic intensity of a lower6or higher. At any rate, the probability that earthquakes will occur at the locations is converted in a scale of maximum 10 points.

Numbers of points about floods, landslide disasters, and tsunami are calculated using “Overlapping hazard maps—a free risk information check” provided at a hazard map portal site (https://disaportal.gsi.go.jp/) run by Ministry of Land, Infrastructure, Transport, and Tourism, for example. With respect to floods, for example, if the location of a fabrication place or a storage place falls into an expected flooded zone (expected maximum scale) that is expected to be flooded due to an overflowing river, then a number of points are given depending on the depth of water in the zone.

For example, in case there is no flooding, i.e., the depth of water is 0.0 m, 0 point is given. In case the depth of water in the zone is larger than 0.0 m and smaller than 0.3 m, 1 point is given. In case the depth of water in the zone is 0.3 m or larger and smaller than 0.5 m, 2 points are given. In case the depth of water in the zone is 0.5 m or larger, 10 points are given. The relatively large number of points are given in case the depth of water in the zone is 0.5 m or larger, because a semiconductor manufacturing apparatus are generally large in size and weight and are relatively frequently installed on the first floor of a building.

With respect to landslide disasters, 5 points are given if the location of a fabrication place or a storage place is in (1) a landslide warning zone on a steep slope, (2) a debris flow warning zone, or (3) a landslide warning zone. Furthermore, 10 points are given if the location of a fabrication place or a storage place is in (4) a landslide special warning zone on a steep slope, (5) a debris flow special warning zone, (6) a landslide special warning zone, near (7) a mountain stream in danger of debris flows, falls into (8) a site in danger of a landslide on a steep slope, (9) a site in danger of a landslide, or (10) a site in danger of avalanches.

By contrast, 0 point is given in case the location of a fabrication place or a storage place does not fall into any of (1) through (10) referred to above. With respect to tsunami, points are given depending on the depth of water in a zone if the location of a fabrication place or a storage place is in a zone that is expected to be flooded due to tsunami (expected maximum scale). As with floods, relatively large numbers of points are given in case the depth of water is 0.5 m or larger. For example, in case there is no tsunami, i.e., in case the depth of water is 0.0 m, no point is given. In case the depth of water in the zone ranges from 0.01 m inclusive to 0.5 m exclusive, 2 points are given. In case the depth of water in the zone ranges from 0.5 m inclusive to 1.0 m exclusive, 5 points are given. In case the depth of water in the zone is 1.0 m or larger, 10 points are given.

The numbers of points in a scale of maximum 40 points with respect to earthquakes, floods, landslide disasters, and tsunami are listed in a column of natural disaster totals, and the numbers of points of the natural disaster totals in the scale of maximum 40 points are converted in a scale of maximum 100 points and listed in a column on the right side of the column of natural disaster totals. In case the locations of fabrication places and storage places are in Japan, as illustrated inFIG.8, the total of 40% of WRI of WRR, 10% of nuclear power plants (the number of points converted in a scale of maximum 100 points), and 50% of natural disaster totals (the number of points converted in a scale of maximum 100 points) is used as a (domestic) total number of points52b(S24inFIG.10).

FIG.8illustrates proportions of WRI of WRR, nuclear power plants (the number of points converted in a scale of maximum 100 points), and natural disaster totals (the number of points converted in a scale of maximum 100 points) in the total numbers of points52bof procurement risks representing geographical factors. The proportion of the natural disaster totals is of a relatively large value of 50% in case the locations are in Japan because domestic information is more detailed than overseas information and hence is considered to reflect more accurate facts.

In contrast, in case the locations of fabrication places and storage places are overseas, not in Japan, as illustrated inFIG.8, the total of 90% of WRI of WRR and 10% of nuclear power plants (the number of points converted in a scale of maximum 100 points) is used as a (overseas) total number of points52b(S24inFIG.10). As it is difficult to obtain detailed predicted values for the respective locations from overseas countries like risks of domestic earthquakes, floods, landslide disasters, and tsunami, assessments of these risks are replaced with WRR values. Therefore, the proportion of WRI is relatively large.

The sum of the total numbers of points52aillustrated inFIG.6and the total numbers of points52billustrated inFIG.7is calculated to obtain total numbers of points of procurement risk in a scale of maximum 200 points (seeFIGS.9and S26inFIG.10). Then, each of the total numbers of points of procurement risk is divided by a maximum total number of points of procurement risk (74.780 of A-2-1in the example illustrated inFIG.9), thereby calculating a procurement risk level coefficient34a(S28inFIG.10). In this manner, procurement risk level coefficients34anormalized such that their maximum value is 1 are calculated respectively with respect to the raw materials22or the partly finished products24.FIG.9illustrates the procurement risk level coefficients34a.FIG.10illustrates a sequence for calculating a procurement risk level coefficient34a.

As illustrated inFIG.1, the required inventory calculating system2has the procurement risk level coefficient calculating section52. The procurement risk level coefficient calculating section52is implemented by a second program read from the memory6and executed by the processor, for example. The procurement risk level coefficient calculating section52calculates procurement risk level coefficients34ain the manner described above on the basis of weights, risk levels (seeFIG.6), WRI, information as to whether there is a nuclear power plant or not, risks of natural disasters such as earthquakes (seeFIG.7) that have been input to the computer4. The memory6further has a sixth area34. The sixth area34stores the procurement risk level coefficients34acalculated by the procurement risk level coefficient calculating section52. Then, required inventories58a(seeFIG.11) are calculated respectively with respect to the raw materials22or the partly finished products24on the basis of the product importance level coefficients32aand the procurement risk level coefficients34a.

FIG.11illustrates required inventories58a, andFIG.12illustrates a sequence for calculating a required inventory58a. First, a general coefficient calculating section54(seeFIG.1) of the required inventory calculating system2calculates general coefficients54arespectively with respect to the raw materials22or the partly finished products24by multiplying the product importance level coefficients32aby the procurement risk level coefficients34a(S30inFIG.12). The general coefficient calculating section54is implemented by a third program read from the memory6and executed by the processor, for example. Inasmuch as the product importance level coefficients32aand the procurement risk level coefficients34aaccording to the present embodiment have already been normalized such that their maximum value is 1, the general coefficients54anormalized such that their maximum value is 1 are obtained by multiplying the product importance level coefficients32aby the procurement risk level coefficients34a.

However, general coefficients54amay be calculated by multiplying coefficient multiplication values44a(seeFIG.4) prior to being normalized as the product importance level coefficients32aby total numbers of points of procurement risk (seeFIG.9) prior to being normalized as the procurement risk level coefficients34a, and thereafter normalizing the products that have been obtained. The higher product importance level coefficients32aare and the higher the procurement risk level coefficients34aare, the higher the general coefficients54aare. In other words, the higher the degree to which the raw materials22or the partly finished products24are needed by the customer18aor the wholesaler18bis and the higher the risk that the raw materials22or the partly finished products24cannot be procured is, the higher the general coefficients54aare.

A required inventory period calculating section56(seeFIG.1) of the required inventory calculating system2calculates required inventory periods56arespectively with respect to the raw materials22or the partly finished products24by multiplying the general coefficients54aby a predetermined longest inventory period (S32inFIG.12). The required inventory period calculating section56is implemented by a fourth program read from the memory6and executed by the processor, for example. If a calculated required inventory period56ais smaller than a predetermined shortest inventory period (YES in S34inFIG.12), then the calculated required inventory period56ais set as the shortest inventory period (S36inFIG.12), i.e., the required inventory period56areplaces the shortest inventory period.

In contrast, if a calculated required inventory period56ais equal to or larger than the predetermined shortest inventory period (NO in S34inFIG.12), then the calculated required inventory period56ais used as it is in a next step. According to the present embodiment, the predetermined longest inventory period represents 24 months. The predetermined longest inventory period of 24 months is determined in view of burdens such as costs imposed as the inventory of the product supplier14increases. According to the present embodiment, the predetermined shortest inventory period represents 6 months. The predetermined shortest inventory period reflects a period indicated to the customer18aor the wholesaler18bas a period in which the product supplier14is able to supply the products12at a certain supply rate to the customer18aor the wholesaler18b, for example.

Then, a required inventory calculating section58(seeFIG.1) of the required inventory calculating system2calculates required inventories58aby multiplying the required quantities30aof the raw materials22or the partly finished products24in the predetermined period, i.e., a 1 month according to the present invention, by the respective calculated required inventory periods56a(S38inFIG.12). The required inventory calculating section58is implemented by a fifth program read from the memory6and executed by the processor, for example. According to the present embodiment, the calculated required inventories58aare regarded as appropriate required inventories58aof the raw materials22or the partly finished products24to be placed in the inventories of the produce supplier14, and are stored in the required inventory calculating system2so as to be reflected in the commercial activities of the product supplier14.

According to the present embodiment, since the required inventory calculating system2automatically calculates required inventories58aof the raw materials22or the partly finished products24in the predetermined period, the required inventories58acan be calculated with a smaller number of man-hours than if they are determined by a worker of the product supplier14. Therefore, the required inventories58aof the raw materials22or the partly finished products24can be calculated less costly than if they are determined by a worker of the product supplier14.

A required inventory calculating system2according to a second embodiment of the present invention will be described below.FIG.13illustrates in block form the required inventory calculating system2according to the second embodiment. According to the second embodiment, a computer60is connected to a server, i.e., a computer,64through the Internet62or a network. Each of the computer60and the server64has a processor and a memory. The computer60stores product names16a, raw material or partly finished product names26a, supplier names28a, required quantities30a, etc., and transmits the stored items of information to the server64through the Internet62.

Predetermined programs stored in a memory of the server64are executed by a processor of the server64, enabling the server64to function as the required inventory calculating system2that has a product importance level coefficient calculating section50, a procurement risk level coefficient calculating section52, a general coefficient calculating section54, a required inventory period calculating section56, and a required inventory calculating section58that are identical to those described above according to the first embodiment. Stated otherwise, various coefficients and items are calculated by the server64, not the computer60. On the basis of the information supplied from the computer60, the server64calculates product importance level coefficients32aand procurement risk level coefficients34a, and also calculates general coefficients54a, required inventory periods56a, and required inventories58a.

Information including the required inventories58ais saved in a memory, not depicted, of the computer60, which belongs to the product supplier14, and is displayed on a display device10. According to the second embodiment, the required inventories58aof the raw materials22or the partly finished products24can be calculated less costly than if they are determined by a worker of the product supplier14.

A required inventory calculating system2according to a third embodiment of the present invention will be described below.FIG.14Aillustrates in block form the required inventory calculating system2according to the third embodiment. According to the third embodiment, a server64stores predetermined programs66that enable a computer60to calculate product importance level coefficients32a, procurement risk level coefficients34a, general coefficients54a, required inventory periods56a, and required inventories58a. The predetermined programs are provided from the server64via the Internet62to the computer60, which belongs to the product supplier14. The computer60functions as the required inventory calculating system2by reading the predetermined programs66. According to the third embodiment, the computer60functions as the required inventory calculating system2that calculates product importance level coefficients32a, procurement risk level coefficients34a, general coefficients54a, required inventory periods56a, and required inventories58a.

A required inventory calculating system2according to a fourth embodiment of the present invention will be described below.FIG.14Billustrates in block form the required inventory calculating system2according to the fourth embodiment. According to the fourth embodiment, predetermined programs66are stored in a non-transitory computer-readable medium such as a USB memory68. The computer60functions as the required inventory calculating system2by reading the predetermined programs66from the non-transitory computer-readable medium.

The structures, methods, etc. according to the above embodiments may be changed or modified appropriately without departing from the scope of the present invention.