Item arrangement system for logistics system and warehouse system

Abstract

An item arrangement system (100) calculates a first co-occurrence degree in a first co-occurrence degree calculation unit (110) on the basis of a shipping data (X), the first co-occurrence degree being a parameter indicating a frequency at which items are shipped simultaneously. A grouping unit (120) uses the first co-occurrence degree to divide items with the high first co-occurrence degree into three or more groups. A second co-occurrence degree acquisition unit (130) determines a second co-occurrence degree, the second co-occurrence degree being a parameter indicating a frequency at which the items between the groups are shipped simultaneously. A first allocation unit (140) determines a combination of adjacent storage areas and the groups so as to maximize the total sum of the second co-occurrence degrees, and allocates the storage areas to the groups. A second allocation unit (150) allocates storage locations for the items included in each group such that the items with a higher shipping frequency are stored closer to pickup locations.

Description

Item placement system and warehouse system for logistics systems

[0001] The present invention relates to an item placement system for a logistics system, and a warehouse system using the item placement system.

[0002] Japanese Patent Laid-Open Publication No. 2021-88427 (Patent Document 1) discloses that in a logistics warehouse, a logistics co-occurrence degree relating to the logistics co-occurrence between items is defined, and multiple items whose logistics co-occurrence degree is equal to or greater than a threshold value are grouped. In Patent Document 1, locations close to each other are determined as storage locations for the grouped items, and the items are stored in the determined locations. Patent Document 1 claims that it is possible to prevent the consumption of resources (time, energy, etc.) related to movement when retrieving items, i.e., the distance the items travel.

[0003] Japanese Patent Application Laid-Open No. 2021-88427

[0004] Logistics co-occurrence is an index related to the frequency with which items x and y are shipped simultaneously (item x and item y exist in a shipping unit (one order)). For this reason, in Patent Document 1, when items included in a group are shipped simultaneously, the consumption of resources related to movement during retrieval (picking) can be reduced. However, when items included in a different group stored far away from the group are shipped simultaneously, there is a concern that the transport distance of the items during retrieval will be long, resulting in increased resource consumption.

[0005] An object of the present disclosure is to improve work efficiency by shortening the transport distance of items when items stored in a storage location are shipped simultaneously.

[0006] 1) The item placement system of the logistics system of the present disclosure includes a first co-occurrence acquisition unit that acquires, for a plurality of items, a first co-occurrence, which is a parameter indicating how often a first item and a second item included in the plurality of items are shipped simultaneously; a grouping unit that divides the items into a plurality of groups based on the first co-occurrence; a second co-occurrence acquisition unit that acquires, for the plurality of groups, a second co-occurrence, which is a parameter indicating how often an item included in the first group divided by the grouping unit and an item included in the second group are shipped simultaneously, based on the first co-occurrence of each of the plurality of items; a first allocation unit that allocates a storage area to each of the plurality of groups based on the second co-occurrence; and a second allocation unit that allocates, to each of the plurality of items, a storage location within the storage area of ​​the group to which the item belongs.

[0007] According to this configuration, the item placement system of the logistics system includes a first co-occurrence acquisition unit, a grouping unit, a second co-occurrence acquisition unit, a first allocation unit, and a second allocation unit. The first co-occurrence is a parameter indicating how often a first item and a second item are shipped simultaneously. The first co-occurrence acquisition unit acquires the first co-occurrence between all items stored in a storage location. The grouping unit divides each item into multiple groups based on the first co-occurrence. The grouping unit divides each item into multiple groups so that the first co-occurrence between items included in each group is high.

[0008] The second co-occurrence is a parameter indicating how often items included in the first group and the second group are shipped at the same time. The second co-occurrence acquisition unit acquires the second co-occurrence between all groups. The first allocation unit allocates storage areas to all groups based on the second co-occurrence. A storage area is an area (region) in which a group is located. The first allocation unit allocates storage areas for each group based on the second co-occurrence. The second allocation unit allocates storage locations within the storage area to items included in the group.

[0009] The second co-occurrence is a parameter that indicates the frequency with which items included in two groups (the first group and the second group) are shipped simultaneously. Therefore, the first allocation unit can use the second co-occurrence to allocate storage areas for each group so that, when items included in different groups are shipped simultaneously, the probability that items included in groups in adjacent storage areas will be shipped simultaneously increases. Therefore, when items stored in storage locations are shipped simultaneously, the transport distance of the items can be shortened, thereby improving work efficiency.

[0010] 2) Preferably, the first allocation unit may determine combinations of storage areas and multiple groups so as to maximize the sum of the second co-occurrence degrees between groups of adjacent storage areas, and allocate the storage areas to the multiple groups.

[0011] According to this configuration, the first allocating unit finds a combination of storage areas and groups that maximizes the sum of the second degrees of co-occurrence between groups allocated to adjacent storage areas. Then, the first allocating unit allocates storage areas to groups so as to maximize the sum of the second degrees of co-occurrence between groups allocated to adjacent storage areas. Since storage areas are allocated to groups so as to maximize the sum of the second degrees of co-occurrence between groups in adjacent storage areas, it is possible to allocate storage areas for each group so that, when items included in different groups are shipped simultaneously, the probability that items included in groups in adjacent storage areas will be shipped simultaneously increases.

[0012] 3) Preferably, in the above items 1 and 2, the second co-occurrence acquisition unit may acquire, as the second co-occurrence degree, the average value or the sum of the first co-occurrence degrees between all of the items included in the first group and the second group.

[0013] According to this configuration, the second co-occurrence degree is calculated by integrating two groups (the first group and the second group) and calculating the "average value" or "sum" of the first co-occurrence degrees of all items included in the integrated group (the two groups). The "average value" and "sum" of the first co-occurrence degrees of all items are suitable indicators of the frequency with which items included in the two groups (the first group and the second group) are shipped simultaneously, and the second co-occurrence degree can be suitably obtained.

[0014] 4) In the above items 1 to 3, the second allocation unit may preferably allocate a storage location closer to the collection location to an item with a higher shipping frequency.

[0015] According to this configuration, an item with a higher loading frequency is allocated to a storage location closer to the collection location, thereby shortening the transport distance of the item when it is shipped.

[0016] 5) A warehouse system according to the present disclosure is a warehouse system that uses the item placement system of the logistics system described above in 1 to 4. The warehouse system includes a conveying device that conveys items stored in a storage location to a collection location provided within the warehouse. A plurality of aisles along which the conveying device moves are provided within the warehouse, and storage locations are provided on both sides of the aisles along which the conveying device moves, and the areas where the storage locations on both sides of the aisles are located may be defined as storage areas.

[0017] According to this configuration, the warehouse system includes a conveying device that conveys items stored in a storage location to a collection location provided within the warehouse. A plurality of aisles along which the conveying device moves are provided within the warehouse. Storage locations are provided on both sides of the aisle along which the conveying device moves. The storage areas are areas in which the storage locations provided on both sides of the aisle are located. Because the warehouse system uses the item placement systems 1 to 4 above, it is possible to shorten the transport distance of items when simultaneously shipping items from each storage area provided on both sides of the aisle, thereby improving work efficiency.

[0018] 6) A warehouse system according to the present disclosure is a warehouse system that uses the item placement system of the logistics system described above in 1 to 4. The warehouse system includes a plurality of collection locations provided within the warehouse, and a plurality of conveying devices that convey items from storage locations to the plurality of collection locations.

[0019] According to this configuration, the warehouse system includes a plurality of conveying devices that convey items from storage locations to each of a plurality of collection locations provided within the warehouse. Because the warehouse system uses the item placement system described in 1 to 4 above, when items belonging to different groups are shipped simultaneously, the probability that items belonging to groups in adjacent storage areas will be shipped simultaneously increases. This shortens the travel distance of each conveying device, thereby reducing the chances of the conveying devices interfering with each other during their travels and preventing a decline in work efficiency in the warehouse.

[0020] 7) A warehouse system according to the present disclosure is a warehouse system that uses the item allocation system for a logistics system described in any one of 1 to 4 above. The warehouse system includes a plurality of collection locations provided within the warehouse, and a plurality of conveying devices that transport the items from storage locations to the plurality of collection locations. The item allocation system for the logistics system further includes a frequency acquisition unit that calculates, for each of a plurality of groups divided by the grouping unit, a group shipping frequency, which is the shipping frequency of the group, based on the shipping frequencies of the items included in the group. The first allocation unit allocates storage areas such that groups with group shipping frequencies equal to or greater than a threshold are not adjacent to each other, and allocates storage areas for groups with group shipping frequencies less than the threshold, based on a second co-occurrence degree of groups.

[0021] According to this configuration, the warehouse system includes a plurality of conveying devices that convey items from storage locations to each of a plurality of collection locations provided within the warehouse. The warehouse system uses the item placement systems described above in 1 to 4. The frequency acquisition unit of the item placement system calculates a group shipping frequency, which is the shipping frequency of each group divided by the grouping unit, based on the shipping frequencies of the items included in the group. The first allocation unit allocates storage areas so that groups with group shipping frequencies equal to or greater than a threshold are not adjacent to each other. The first allocation unit allocates storage areas to groups with group shipping frequencies less than the threshold based on the second co-occurrence of the groups.

[0022] Groups with a group shipping frequency equal to or greater than the threshold are assigned storage areas that are not adjacent to each other, reducing the chance of interference between the transport devices during transport of the items. Furthermore, groups with a group shipping frequency less than the threshold are assigned storage areas based on the second co-occurrence, increasing the probability that items in groups in adjacent storage areas will be shipped simultaneously when the items in these groups are shipped simultaneously, thereby reducing the travel distance of each transport device.

[0023] According to the present disclosure, when items stored in a storage location are shipped simultaneously, the transport distance of the items can be shortened and work efficiency can be improved.

[0024] FIG. 1 is a schematic configuration diagram showing an example of the overall configuration of a logistics system according to the present embodiment. FIG. 2 is a diagram explaining an example in which grouped items are stored in nearby storage locations in a comparative example. FIG. 3 is a diagram explaining functional blocks of an item placement system according to the present embodiment. FIG. 4 is a diagram explaining allocation patterns according to the present embodiment. FIG. 5 is a diagram explaining storage locations when storage areas are allocated to groups by a first allocation unit. FIG. 6 is a diagram explaining an example in which the item placement system is applied to the storage of items between warehouses. FIG. 7 is a diagram explaining functional blocks of an item placement system according to a first modified example. Similar to FIG. 2, it is a diagram explaining an example in which grouped items are stored in nearby storage locations in a comparative example. FIG. 8 is a diagram explaining functional blocks of an item placement system 100A according to a second modified example.

[0025] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are designated by the same reference numerals, and description thereof will not be repeated.

[0026] FIG. 1 is a schematic diagram showing an example of the overall configuration of a logistics system 1 according to this embodiment. The logistics system 1 includes a warehouse 10, a control device 200, and a server 300. In this embodiment, the warehouse 10 is an indoor warehouse that stores items 20, and the items 20 are laid flat on the floor. The control device 200 is installed inside a building of the warehouse 10. The control device 200 manages the items 20, controls the conveying device 13, and the like. The server 300 can communicate with the control device 200 via a network NW. The server 300 functions as a host system of the control device 200, and manages, for example, the logistics of multiple warehouses 10. The control device 200 and the server 300 are computers configured with a CPU (Central Processing Unit), memory, and the like.

[0027] In the warehouse 10, dashed-line squares Sq indicate the travel path of the conveying device 13, and the conveying device 13 travels (moves) along the squares Sq. In this embodiment, items 20 are stored on the floor of the storage space 11. The storage space 11 is partitioned for each item 20, and is partitioned into two rows along the aisle 12 along which the conveying device 13 travels. In this embodiment, the storage space 11 is partitioned into ten units (ten sections), with five sections per row. A plurality of storage spaces 11 partitioned into two rows are installed with the aisle 12 between them. FIG. 1 illustrates an area in which four storage spaces 11 (11a to 11d) are installed with three aisles 12 (12a to 12c) between them. The areas in the storage space 11 partitioned for each item 20 are storage locations for the items 20. The items 20 may be placed on pallets and stored in storage locations (sections), or may be stored in storage boxes or the like provided in the storage location.

[0028] The conveying device 13 conveys items 20 stored in a storage location (storage space 11) to a collection location 14. The conveying device 13 is controlled by a control device 200. The control device 200 specifies items to be picked by the conveying device 13 for each shipping unit. The specified items are also referred to as requested items. The conveying device 13 travels (moves) along the grid Sq and conveys requested items stored in the storage location to the collection location 14. If the shipping unit contains multiple requested items, this transport is repeated. The conveying device 13 may be, for example, an automated guided vehicle (AGV), an autonomous mobile robot (AMR), or the like.

[0029] When a shipping unit (one order) contains multiple requested items (multiple items to be shipped simultaneously), the items can be grouped and stored in storage locations close to each other, thereby improving work efficiency during shipping. FIG. 2 is a diagram illustrating an example of storing grouped items in storage locations close to each other in a comparative example. In FIG. 2, items 20 are stored in all of the storage locations (sections) of storage spaces 11a to 11d, and the symbols A to J represent specific items 20 and the storage locations of those items 20.

[0030] Referring to FIG. 2, storage areas in which grouped items 20 are stored adjacent to one another are set on both sides of aisles 12a to 12c. In FIG. 2, the storage areas are indicated by two-dot chain lines. Storage area a is set on both sides of aisle 12a, is composed of a right-hand row of storage spaces 11a and a left-hand row of storage spaces 11b, and includes ten storage locations (sections). Storage area b is set on both sides of aisle 12b, is composed of a right-hand row of storage spaces 11b and a left-hand row of storage spaces 11c, and includes ten storage locations (sections). Storage area c is set on both sides of aisle 12c, is composed of a right-hand row of storage spaces 11c and a left-hand row of storage spaces 11c, and includes ten storage locations (sections). Storage area a and storage area b are adjacent to one another, and storage area b and storage area c are adjacent to one another. Storage area a and storage area c are not adjacent to one another.

[0031] In Figure 2, items 20 included in a group are surrounded by a dashed line. Group 1 (Gr1) is assigned to storage area a, and the items included in Gr1 are stored in the storage location of storage area a. Group 2 (Gr2) is assigned to storage area b, and the items included in Gr2 are stored in the storage location of storage area b. Group 3 (Gr3) is assigned to storage area c, and the items included in Gr3 are stored in the storage location of storage area c. Items A, B, C, and D are frequently shipped together, and are included in Gr1. Items E, F, and G are frequently shipped together, and are included in Gr2. Items H, I, and J are frequently shipped together, and are included in Gr3.

[0032] When the control device 200 commands items A, C, and D included in Gr1 to be shipped simultaneously (as required items in a shipping unit), the travel distance (number of squares Sq) of the conveying device 13 is 34. The conveying device 13 starts picking from the initial position St, and after picking all the required items, returns to the initial position St. In this case, items A, C, and D are frequently shipped simultaneously and are included in Gr1, so they are stored in a storage location in storage area a, and the travel distance of the conveying device 13 can be shortened.

[0033] When the control device 200 commands items A and C included in Gr1 and item H included in Gr3 as requested items to be shipped simultaneously (although this is less frequent than commands for items A, C, and D), the travel distance (number of squares Sq) of the conveying device 13 is 50. Item H is included in Gr3 and is stored in a storage location in storage area c. Storage area a, where items A and C included in Gr1 are stored, is separated from storage area c (not adjacent), and the travel distance of the conveying device 13 becomes longer when items 20 included in storage area a and storage area c are shipped simultaneously.

[0034] In this embodiment, the travel distance of the conveying device 13 can be reduced by allocating storage areas for each group using a parameter representing the frequency with which items are shipped simultaneously between groups.

[0035] 3 is a diagram illustrating the functional blocks of the item placement system 100 in this embodiment. The item placement system 100 is configured by a control device 200 and / or a server 300. These functional blocks may be configured in either the control device 200 or the server 300, or may be configured by the control device 200 and the server 300 working together.

[0036] 3, the first co-occurrence obtaining unit 110 obtains the first co-occurrence using the shipping data X. The shipping data X is data on items shipped in a predetermined period (e.g., 30 days, 90 days, etc.). The shipping data X includes data on items in shipping units (data on a combination of items shipped at the same time).

[0037] The first co-occurrence is a parameter representing the frequency with which a first item (item x) and a second item (item y) are shipped simultaneously. The first co-occurrence acquisition unit 110 calculates the first co-occurrence using the probability P(x, y) that items x and y are shipped simultaneously, for example, by utilizing pointwise mutual information (PMI). (P(x, y) is also referred to as the co-occurrence probability.)

[0038] The first co-occurrence acquiring unit 110 obtains the probability P(x) that item x will be shipped, the probability P(y) that item y will be shipped, and the co-occurrence probability P(x, y) from the shipping data X, and calculates the PMI(x, y) using the following formula 1: PMI(x, y) = log [P(x, y) / (P(x) * P(y))] ... (Formula 1) Next, the first co-occurrence acquiring unit 110 obtains the total positive self information (PPMI) using the following formula 2: PPMI(x, y) = max(0, PMI(x, y) ... (Formula 2)

[0039] The first co-occurrence obtaining unit 110 calculates PPMI(x, y) for all items included in the shipping data X, and stores the PPMI(x, y) between all items in memory as first co-occurrences. A first co-occurrence table 110A is an example of data stored in memory, and "*" indicates the value of the first co-occurrence (PPMI(x, y)).

[0040] The first co-occurrence degree may be, for example, a co-occurrence probability P(x, y) other than PPMI(x, y). Alternatively, the cosine similarity (cos(x, y)) of P(x) and P(y) may be used as the first co-occurrence degree.

[0041] The grouping unit 120 groups items based on the information on the first co-occurrence (PPMI(x, y)) in the first co-occurrence table 110A. The grouping unit 120 groups items with a high first co-occurrence. In this embodiment, one group includes 10 items, which is the capacity of the storage area, and the number of groups is three, which is the number of storage areas. The grouping unit 120 groups items with a high first co-occurrence using machine learning clustering. As a result, the grouping unit 120 groups each item 20 so that the first co-occurrence between items included in the group is high (large). Alternatively, an optimization algorithm using simulated annealing or a determination algorithm using a rule-based method may be used. The group table 120A is a result of grouping and is an example of data stored in memory. Note that if there are items that are never shipped together (items with a first co-occurrence of 0 with any other item), these items may be divided into groups (non-co-occurrence groups).

[0042] The second co-occurrence acquiring unit 130 acquires second co-occurrences from the information in the first co-occurrence table 110A and the group table 120A. The second co-occurrence is a parameter indicating the frequency with which items included in a first group (e.g., Gr1) and a second group (e.g., Gr2) are shipped simultaneously. In this embodiment, the second co-occurrence acquiring unit 130 acquires the average value of the first co-occurrences between the items included in the first group and the second group as the second co-occurrence. For example, Gr1 and Gr2 are integrated, and the average value of the first co-occurrences between all items (items A, B, ... E, F, ... a total of 20 items) included in the integrated group (Gr1 and Gr2) is calculated as the second co-occurrence between Gr1 and Gr2. The second co-occurrence acquiring unit acquires the second co-occurrences between all groups. The second co-occurrence table 130A is an example of data stored in memory, and represents a case where the second co-occurrence degree between Gr1 and Gr2 is "0.1", the second co-occurrence degree between Gr1 and Gr3 is "1.2", and the co-occurrence degree between Gr2 and Gr3 is "0.8". Note that the second co-occurrence acquisition unit 130 may calculate the "sum" of the first co-occurrence degrees between all of the items included in the two combined groups as the second co-occurrence degree, or it may be the "variance" or "best value" between all of the items.

[0043] The first allocation unit 140 allocates storage areas to groups based on the information in the second co-occurrence table 130A. The first allocation unit 140 determines the combination of adjacent storage areas and groups that maximizes the sum of the second co-occurrence degrees, and allocates the storage areas to the groups. Figure 4 is a diagram illustrating allocation patterns in this embodiment. Figure 4 shows an example in which storage areas a, b, and c are adjacent in this order as in Figure 2, and items 20 are grouped into three groups (Gr1 to Gr3), but the combinations of storage areas and groups are different.

[0044] 4, allocation pattern 1 is a pattern in which Gr1 is allocated to storage area a, Gr2 is allocated to storage area b, and Gr3 is allocated to storage area c (Gr1-Gr2-Gr3). Pattern 2 is a pattern in which Gr1 is allocated to storage area a, Gr3 is allocated to storage area b, and Gr2 is allocated to storage area c (Gr1-Gr3-Gr2). Pattern 3 is a pattern in which Gr2 is allocated to storage area a, Gr1 is allocated to storage area b, and Gr3 is allocated to storage area c (Gr2-Gr1-Gr3).

[0045] According to the second co-occurrence degrees in the second co-occurrence degree table 130A (see FIG. 3), the sum of the second co-occurrence degrees in pattern 1 is 0.9, the sum of the second co-occurrence degrees in pattern 2 is 2.0, and the sum of the second co-occurrence degrees in pattern 3 is 1.3. The first allocation unit 140 determines the combination of adjacent storage areas and groups so as to maximize the sum of the second co-occurrence degrees, and allocates storage areas a to c to groups (Gr1 to Gr3). Therefore, in this embodiment, an allocation pattern of pattern 2 is set. (Note that in this embodiment, since the arrangement of storage areas a to c is symmetrical, pattern 1 (Gr1-Gr2-Gr3) is the same as pattern 4 (Gr3-Gr2-Gr1), and pattern 4 is not considered.)

[0046] The second allocation unit 150 allocates storage locations within the storage area to the items 20 included in each group. The second allocation unit 150 extracts the items included in the group by referring to the group table 120A. Then, for example, the storage location is allocated so that the higher the probability (shipping frequency) of an item being shipped, the closer the item is to be stored in a storage location (section) closer to the collection location 14. For example, if item A included in Gr1 has a higher shipping frequency than item C, item A is allocated a storage location closer to the collection location 14 than item C. In this embodiment, the shorter the travel distance of the conveying device 13 from the initial position St to the storage location, the closer the storage location is to be allocated to the collection location 14.

[0047] FIG. 5 is a diagram illustrating storage locations when the first allocation unit 140 allocates storage areas to groups. As described above, the first allocation unit 140 sets allocation pattern 2, which maximizes the sum of the second co-occurrence degrees. In pattern 2, as shown in FIG. 5, Gr1 is allocated to storage area a, Gr3 is allocated to storage area b, and Gr2 is allocated to storage area c. When storage areas are allocated to each group in this manner, when the control device 200 instructs items A, C, and D included in Gr1 to be shipped simultaneously, the travel distance (number of squares Sq) of the conveying device 13 is 34, as in the case of FIG. 2. When the control device 200 instructs items A, C, and H included in Gr1 to be shipped simultaneously, the travel distance (number of squares Sq) of the conveying device 13 is 44, which is shorter than the case of FIG. 2.

[0048] The first allocating unit 140 determines the combination of adjacent storage areas and groups so as to maximize the sum of the second co-occurrence degrees, and allocates storage areas a to c to the groups, so that the frequency with which items included in groups allocated to adjacent storage areas are shipped simultaneously increases compared to the allocation of storage areas in Figure 2. This makes it possible to shorten the travel distance of the conveying device 13.

[0049] The second allocation unit 150 allocates an item within a group with a higher shipping frequency to a storage location closer to the collection location 14. For example, in FIG. 5, the shipping frequencies of items A to D included in Gr1 are "A>D>B>C", and the higher the shipping frequency, the closer the item is allocated to a storage location (section) closer to the collection location 14. The higher the shipping frequency, the closer the item is stored to the collection location 14, so it is possible to shorten the travel distance of the conveyance device 13 during picking.

[0050] The items 20 may be stored (entered) into a storage location (section) using the conveying device 13, or may be entered using a conveying device for warehousing (not shown). Alternatively, a worker may enter (store) the items 20 into the storage location using an instruction sheet output from the item placement system 100, an electronic kanban, or the like. The warehouse 10 equipped with the conveying device 13, the control device 200, and the like corresponds to an example of a "warehouse system" of the present disclosure.

[0051] In the above embodiment, the item placement system 100 of the logistics system 1 has been described as being applied to the storage of items within the warehouse 10. However, the item placement system 100 can also be applied to cases where items are collected from multiple warehouses at a collection center. FIG. 6 is a diagram illustrating an example in which the item placement system 100 is applied to the storage of items between warehouses. Referring to FIG. 6, a truck 510 collects items stored in multiple warehouses A to D and sends them to a collection center 500. In this example, the warehouses correspond to storage areas, with warehouse A set as storage area a, warehouse B set as storage area b, warehouse C set as storage area c, and warehouse D set as storage area d. Each of warehouses A to D is equipped with a control device 200 capable of communicating with the server 300 via a network NW, and constitutes the item placement system 100.

[0052] As in the above embodiment, the item placement system 100 calculates the first co-occurrence between items from the shipping data X and groups the items based on the first co-occurrence. In the example of FIG. 6, there are four storage areas (warehouses), so the items are grouped into four groups (Gr1 to Gr4). The second co-occurrence between the groups is then calculated, and a combination of adjacent warehouses A to D (storage areas A to D) and groups is determined so as to maximize the sum of the second co-occurrences, and the storage areas A to D (warehouses A to D) are assigned to the groups (Gr1 to Gr4). Furthermore, the item placement system 100 assigns storage locations for items included in a group that are closer to the exits of each warehouse A to D the higher the shipping frequency.

[0053] According to this example, the combination of adjacent storage areas (warehouses A to D) and groups is determined so as to maximize the sum of the second co-occurrence degrees, and the storage areas (warehouses A to D) are assigned to the groups, so that items included in groups assigned to adjacent storage areas (warehouses A to D) are shipped simultaneously more frequently, thereby making it possible to shorten the travel distance of truck 510.

[0054] (Variation 1) Figure 7 is a diagram illustrating a warehouse 10A in Variation 1. The warehouse 10A in Variation 1 further includes collection locations 14a and 14b, and conveyance devices 13a and 13b in addition to the warehouse 10 in the above embodiment. The warehouse 10A includes multiple collection locations 14, 14a, and 14b, and multiple conveyance devices 13, 13a, and 13b. The conveyance device 13 conveys stored items to the collection location 14. The conveyance device 13a conveys stored items to the collection location 14a. The conveyance device 13b conveys stored items to the collection location 14b. The storage locations of each item are set by the item placement system 100 in the same manner as in the above embodiment.

[0055] In Modification 1, as in the above embodiment, the first allocation unit 140 determines the combination of adjacent storage areas and groups so as to maximize the sum of the second co-occurrence degrees, and allocates storage areas a to c to the groups. This increases the frequency with which items included in groups assigned to adjacent storage areas are shipped simultaneously, making it possible to shorten the travel distances of the conveying devices 13, 13a, and 13b. This makes it possible to prevent the conveying devices from congesting when multiple conveying devices are shipping.

[0056] For example, assume that items A, C, and H are instructed to conveyance device 13, items H and I are instructed to conveyance device 13a, and items G and E are instructed to conveyance device 13b as requested items to be shipped simultaneously (as requested items in a shipping unit). Note that items H and I are grouped by the first co-occurrence degree so that items H and I are frequently shipped simultaneously, and items G and E are frequently shipped simultaneously.

[0057] Fig. 8 is a diagram illustrating an example of storing grouped items in a nearby storage location in a comparative example, similar to Fig. 2. In this case, as shown in Fig. 8, the travel paths of conveying device 13 and conveying devices 13a and 13b overlap (interfere), which may cause conveying devices 13a and 13b to become stuck on their travel paths, which may reduce work efficiency.

[0058] In contrast, in Modification 1, as shown in Fig. 7, the items picked by conveying device 13 are assigned to adjacent storage areas, so the warehouse routes of conveying device 13 and conveying device 13b do not overlap (interfere). This makes it possible to prevent conveying device 13b from being congested, and to prevent a decrease in work efficiency. Note that in Modification 1, some or all of Warehouses A to D may be used as storage areas for items or products in a factory or the like.

[0059] (Modification 2) Fig. 9 is a diagram illustrating the functional blocks of an item placement system 100A in Modification 2. The item placement system 100A in Modification 2 includes a frequency calculation unit 160 in addition to the functions of the item placement system 100 in the above embodiment. The functions of the first co-occurrence acquisition unit 110, the grouping unit 120, and the second assignment unit 150 are substantially the same as those in the above embodiment.

[0060] The frequency calculation unit 160 calculates the shipping frequency of the groups grouped by the grouping unit 120. For example, the frequency calculation unit 160 extracts items included in the group by referring to the group table 120A (see FIG. 3). The frequency calculation unit 160 calculates the sum ΣP of the shipping probabilities (shipping frequencies) of all items included in the group, and sets the sum ΣP as the shipping frequency of the group. Then, it identifies a group whose sum ΣP is equal to or greater than a threshold α. Note that the frequency calculation unit 160 may also calculate the average Pave of the shipping probabilities (shipping frequencies) of all items included in the group, set the average Pave as the shipping frequency of the group, and identify a group whose average Pave is equal to or greater than a threshold β. Furthermore, the threshold α may be set so that, for example, two or more groups that rank higher in the group with the highest sum ΣP can be identified.

[0061] The second co-occurrence obtaining unit 130 obtains the second co-occurrence between groups, similarly to the above embodiment, for groups not identified by the frequency calculation unit 160 (groups whose sum ΣP is less than the threshold value α). Note that the second co-occurrence obtaining unit 130 does not necessarily need to obtain information on groups not identified from the frequency calculation unit 160. In that case, it is sufficient to obtain the second co-occurrence between all groups.

[0062] The first allocation unit 140 allocates storage areas to groups identified by the frequency calculation unit 160 (groups whose sum ΣP is equal to or greater than the threshold value α) so that the groups are not adjacent to each other. Furthermore, for groups for which the second co-occurrence degree has been acquired, the first allocation unit 140 determines a combination of adjacent storage areas and groups so that the sum of the second co-occurrence degrees is maximized, and allocates storage areas to the groups, in the same way as in the above embodiment.

[0063] The item placement system 100A of the second modification is applied to a warehouse equipped with multiple conveying devices, such as the warehouse 10A of the first modification. It is particularly suitable for a warehouse with five or more storage areas. In the second modification, groups whose items are frequently shipped together are assigned to distant storage areas. Therefore, in a warehouse equipped with multiple conveying devices, overlapping travel routes of the conveying devices can be prevented, which can prevent the conveying devices from being congested and reduce declines in work efficiency. Furthermore, for groups whose items are relatively infrequently shipped together, a combination of adjacent storage areas and groups is determined so as to maximize the sum of the second co-occurrence degrees, and a storage area is assigned to the group, thereby shortening the travel distance of the conveying devices.

[0064] In the above embodiment, the warehouse is a warehouse where items are laid out flat. However, it may be an automated warehouse with multiple shelves arranged vertically (up and down), and the conveying device may be a stacker crane or the like. In this case, the second allocating unit 150 may allocate items with a higher shipping frequency to a storage location that requires a shorter transport time to the collection location.

[0065] In the above embodiment, a warehouse was used as an example, but the storage location of items determined by the item placement system 100 may also be applied to the placement of containers at ports, the placement of items and products (inventory) within factories, etc.

[0066] In the above embodiment, an example of picking using the conveying device 13 has been described, but it may be picking by a worker, joint picking by a worker and a conveying device (robot), picking using a forklift, etc. Also, although an example of the conveying device 13 conveying one item at a time has been described, it may be applied to a conveying device that can convey multiple items at a time.

[0067] In the above embodiment, the case where the number of storage areas is 3 to 5 has been described, but the number of storage areas may be any number equal to or greater than 3. Note that items for which a storage location is specified due to the characteristics of the items 20 do not need to be grouped by the grouping unit. For example, for items that require refrigeration, the storage location may be determined so that the items are stored in a storage area (warehouse) equipped with refrigeration equipment, and the items may be excluded from the storage area allocation targets of the present disclosure.

[0068] The item allocation system 100, 100A may set the allocation of storage locations for items periodically, for example, quarterly. Alternatively, the allocation of storage locations may be set each time a model change of the target item occurs. Once the second allocation unit 150 has received shipping frequency information from the shipping data X and grouping information from the grouping unit 120, it may determine the allocation of items within the storage area without waiting for processing by the second co-occurrence acquisition unit 130 or the first allocation unit 140.

[0069] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present invention is defined by the claims, not by the description of the above embodiments, and is intended to include all modifications within the meaning and scope of the claims.

[0070] REFERENCE SIGNS LIST 1 Logistics system 10, 10A Warehouse 11 Storage space 12 Passage 13 Conveying device 14 Collection location 20 Item 100, 100A Item placement system 110 First co-occurrence acquisition unit 120 Grouping unit 130 Second co-occurrence acquisition unit 140 First allocation unit 150 Second allocation unit 160 Frequency calculation unit 200 Control device 300 Server 410 Truck 500 Collection center

Claims

1. An item allocation system for a logistics system, comprising: a first co-occurrence acquisition unit that acquires a first co-occurrence, which is a parameter indicating how often a first item and a second item included in a plurality of items are shipped simultaneously; a grouping unit that divides the plurality of items into a plurality of groups based on the first co-occurrence; a second co-occurrence acquisition unit that acquires a second co-occurrence, which is a parameter indicating how often an item included in a first group divided by the grouping unit and an item included in a second group are shipped simultaneously, based on the first co-occurrence of each of the plurality of items; a first allocation unit that allocates a storage area to each of the plurality of groups based on the second co-occurrence; and a second allocation unit that allocates, to each of the plurality of items, a storage location within the storage area of ​​the group to which the item belongs.

2. An item placement system for a logistics system as described in claim 1, wherein the first allocation unit determines combinations of the storage areas and the multiple groups so as to maximize the sum of the second co-occurrence degrees between groups of adjacent storage areas, and allocates the storage areas to the multiple groups.

3. An item placement system for a logistics system as described in claim 1 or claim 2, wherein the second co-occurrence acquisition unit acquires the average or sum of the first co-occurrence between all items included in the first group and the second group as the second co-occurrence.

4. An item allocation system for a logistics system according to claim 1 or 2, wherein the second allocation unit allocates the storage location closer to the collection location to an item with a higher shipping frequency.

5. A warehouse system using the item placement system of the logistics system described in claim 1 or claim 2, comprising a conveying device that conveys the items stored in the storage location to a collection location located within the warehouse, wherein a plurality of aisles are provided within the warehouse along which the conveying device moves, the storage locations are provided on both sides of the aisles along which the conveying device moves, and the storage area is the area in which the storage locations located on both sides of the aisle along which the conveying device moves are located.

6. A warehouse system using the item placement system of the logistics system according to claim 1 or 2, comprising: a plurality of collection locations provided within the warehouse; and a plurality of conveying devices for conveying items from the storage location to the plurality of collection locations.

7. A warehouse system using the item placement system of the logistics system described in claim 1, comprising: a plurality of collection locations set up within the warehouse; and a plurality of conveying devices that transport items from the storage locations to the plurality of collection locations, wherein the item placement system further comprises a frequency acquisition unit that calculates, for each of the plurality of groups divided by the grouping unit, a group shipping frequency that is the shipping frequency of the group based on the shipping frequency of the items included in the group, and wherein the first allocation unit allocates the storage areas so that groups whose group shipping frequencies are equal to or greater than a threshold are not adjacent to each other, and allocates the storage areas of groups whose group shipping frequencies are less than the threshold based on the second co-occurrence degree.

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