Abstract:
On the basis of picking-operation-results information for each component, component-shelf-interval-distance information, and component-shelf-layout information, which is all stored in a storage unit, this component-shelf-layout design device calculates picking-movement distance and replacement-occurrence frequency and extracts an optimal component-shelf layout proposal from among the current component-shelf layout and a plurality of newly generated component-shelf layout proposals. Said configuration makes it possible to design a component-shelf layout proposal which makes it possible to efficiently execute a component-shelf picking operation and a component-shelf replacement operation in a production/distribution facility.

Description:
TECHNICAL FIELD 
       [0001]    The present invention relates to a layout design of component shelves in warehouse in a production/distribution facility. 
       BACKGROUND ART 
       [0002]    A typical example of an operation for delivering a desired component from warehouse is a picking operation. A form of the picking operation is a method in which an operator collects a specified component while moving around component shelves. For performing the picking operation efficiently in this method, it is important to optimize the arrangement of the component shelves in a picking area. Determination of the component-shelf arrangement described above is called component-shelf-layout design. 
         [0003]    An example of a conventional method of the component-shelf-layout design that aims to improve the efficiency of the picking operation is a method described in Patent Literature 1 in which the arrangement of the component shelves is determined in accordance with a delivery frequency of each component. According to Patent Literature 1, an instruction to change a layout is issued in such a manner that a component having a high delivery frequency is arranged at a closer position to a reference position and a component having a low delivery frequency is arranged at a farther position from the reference position. Changing the component-shelf layout in accordance with the above-described method enables a picking operator to perform the picking operation in a shorter movement distance, so that the efficiency of the picking operation can be improved. 
       CITATION LIST 
     Patent Literature 
       [0004]    Patent Literature 1: Japanese Unexamined Patent Application Publication No. 2011-215715 
       SUMMARY OF THE INVENTION 
     Problems to be Solved by the Invention 
       [0005]    The conventional component-shelf-layout design method, such as Patent Literature 1, focuses only on the traveling movement distance in picking to improve the efficiency of the picking operation. Meanwhile, when component stock on a component shelf has decreased in an actual delivery facility, it is necessary to replenish components to the component shelf in the picking area from a backward storage shelf where components are stored. When the component stock on the component shelf has run out (stockout has occurred), the picking operation is interrupted. Therefore, for improving the efficiency of the picking operation, it is important to perform replenishment to prevent stockout. 
         [0006]    In a component replenishment operation, a method is usually used in which when the component stock on the component shelf is below a threshold value (a replenishment point), the components are replenished until the stock amount reaches a preset number of components (a replenishment amount). An occurrence frequency of the replenishment operation is determined by the size of a component shelf to which each component is allocated. For example, as the component shelf for the component is larger, the replenishment amount can be set to be larger. Therefore, more components can be replenished in one replenishment operation, so that the occurrence frequency of the replenishment operation can be lowered. When the occurrence frequency of the replenishment operation is lowered, an occurrence of the stockout caused by delay of the replenishment operation can be suppressed. However, the larger component shelf increases an occupation area of the component shelf in the picking area and therefore the traveling movement distance in the picking is increased. As described above, it is necessary to consider both reduction of the traveling movement distance in the picking and suppression of the occurrence of the replenishment operation in the component-shelf-layout design. 
       Solution to the Problem 
       [0007]    In order to solve the above problem, the present invention is configured to include a storage unit and a control unit, for example. The storage unit stores picking-operation-results information including information on a delivery amount of each component, component-shelf-distance information including information on a distance between component shelves, and component-shelf-layout information indicating a component shelf, a component allocated to the component shelf, and the capacity of the component shelf. The control unit includes a picking-movement distance calculation unit calculating a picking-movement distance in each component-shelf layout using the information in the storage unit, a replenishment-occurrence frequency calculation unit calculating an occurrence frequency of a replenishment operation using the information in the storage unit, and a new component-shelf layout creation unit creating a plurality of new component-shelf layout proposals and adding them to the component-shelf-layout information. The picking-movement distance calculation unit and the replenishment-occurrence frequency calculation unit calculate the picking-movement distances and the occurrence frequencies of the replenishment operation for a current component-shelf layout and the component-shelf layout proposals created by the new component-shelf layout creation unit. An optimal component-shelf layout extraction unit is further provided that extracts a component-shelf layout proposal satisfying a predetermined condition from the component-shelf layout proposals created by the new component-shelf layout creation unit. 
       Advantageous Effects of the Invention 
       [0008]    According to the present invention, a user of this device can determine a component-shelf layout that can improve the efficiency of a picking operation and suppress an occurrence of a replenishment operation simultaneously. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]      FIG. 1  is a functional block diagram of a component-shelf-layout design device. 
           [0010]      FIG. 2  is a schematic diagram of a component-shelf-layout design system. 
           [0011]      FIG. 3  is a schematic diagram showing a picking operation. 
           [0012]      FIG. 4  is a schematic diagram of a picking-operation-results information table. 
           [0013]      FIG. 5  is a schematic diagram of a component/shelf allocation-availability information table. 
           [0014]      FIG. 6  is a schematic diagram of a component-shelf-distance information table. 
           [0015]      FIG. 7  is a schematic diagram of a component-shelf-layout information table. 
           [0016]      FIG. 8  is a schematic diagram of a component-shelf-layout change information table. 
           [0017]      FIG. 9  is a schematic diagram of a picking-operation information table. 
           [0018]      FIG. 10  is a schematic diagram of a replenishment-operation information table. 
           [0019]      FIG. 11  is a schematic diagram of a parameter information table. 
           [0020]      FIG. 12  is a flowchart showing a component-shelf-layout design process. 
           [0021]      FIG. 13  is a schematic diagram showing an example of a display screen. 
           [0022]      FIG. 14  is a schematic diagram showing an example of the display screen. 
       
    
    
     DESCRIPTION OF EMBODIMENTS 
       [0023]    Details of an embodiment of the present invention are described below. 
         [0024]      FIG. 3  is a schematic diagram showing a picking operation. As shown in  FIG. 3 , a picking area includes a plurality of component shelves therein, on each of which components are arranged. A picking operator starts from a picking-start point and travels the picking area to collect a plurality of components. Upon completing collecting all the instructed components, the picking operator moves to a picking-end point. When a stock amount on each component shelf is below a replenishment point, a replenishment operator replenishes components from a backward storage shelf to make the stock amount on the component shelf equal to a set replenishment amount. A component-shelf-layout design device according to the present invention is for the above-described operations, for example, and provides a user to a component-shelf-layout change proposal considering both reduction of a picking-movement distance and suppression of occurrence of the replenishment operation. 
         [0025]      FIG. 1  is a functional block diagram of a component-shelf layout proposal design device. As shown in  FIG. 1 , the component-shelf layout proposal design device includes a storage unit  110 , a control unit  120 , a display unit  130 , and a communication unit  140 . 
         [0026]    The storage unit  110  includes a picking-operation-results information storage area  111 , a component/shelf allocation-availability information storage area  112 , a component-shelf-distance information storage area  113 , a component-shelf-layout information storage area  114 , a component-shelf-layout change information storage area  115 , a picking-operation information storage area  116 , a replenishment-operation information storage area  117 , and a parameter information storage area  118 . 
         [0027]    The picking-operation-results information storage area  111  stores information specifying a result of a past picking operation therein. In the present embodiment, for example, a picking-operation-results information table shown in  FIG. 4  is stored. As shown in  FIG. 4 , the picking-operation-results information table has a round-number column  111   a , a component-name column  111   b , a delivery-amount column  111   c , and an operation date-and-time column  111   d . The round-number column  111   a  stores information specifying a round number. A round described here refers to a series of operations starting from the picking-start point, traveling the component shelves to collect all instructed components, and arriving at the picking-end point. The round number is a number uniquely given to the above series of operations. The component-name column  111   b  stores information specifying a component name. The delivery-amount column  111   c  stores information specifying the number of corresponding component(s) collected in the corresponding round. The operation date-and-time column  111   d  stores information specifying an actual date and time of completion of collecting the corresponding component(s) in the corresponding round. 
         [0028]    The component/shelf allocation-availability information storage area  112  stores therein information specifying availability of allocation of each component to each component shelf. In the present embodiment, for example, a component/shelf allocation-availability information table shown in  FIG. 5  is stored. As shown in  FIG. 5 , the component/shelf allocation-availability information table includes a component-name column  112   a , a shelf-name column  112   b , an allocation availability column  112   c , a replenishment-point column  112   d , and a replenishment-amount column  112   e . The component-name column  112   a  stores information specifying a component name. The shelf-name column  112   b  stores information specifying a component-shelf name. The allocation availability column  112   c  stores information specifying whether allocation of the corresponding component to the corresponding component shelf is available. The replenishment-point column  112   d  and the replenishment-amount column  112   e  store information specifying the replenishment point and the replenishment amount when the corresponding component is allocated to the corresponding component shelf, respectively. This table can be created based on a component size or various kinds of restrictions in the site. For example, allocation availability can be set to be “NOT AVAILABLE” when the component size is larger than a component-shelf size. The replenishment amount of a component for a component shelf can be calculated from the width, height, and depth of a corrugated cardboard box in which that component is put and the width, height, and depth of that component shelf. 
         [0029]    The component-shelf-distance information storage area  113  stores information specifying a distance between a component shelf and another component shelf. In the present embodiment, a component-shelf-distance information table shown in  FIG. 6  is stored, for example. As shown in  FIG. 6 , the component-shelf-distance information table includes a start-point shelf-name column  113   a , an end-point shelf-name column  113   b , and a distance column  113   c . Each of the start-point shelf-name column  113   a  and the end-point shelf-name column  113   b  stores information specifying the name of a component shelf. The distance column  113   c  stores information specifying the distance from the corresponding start-point component shelf to the corresponding end-point component shelf. The distance information stored in the distance column is not necessarily a straight-line distance between the shelves, but is a distance of a moving route in the movement in the picking operation from the corresponding start-point component shelf to the corresponding end-point component shelf. This table also stores information on distances from the start point of the picking operation to each component shelf and from each component shelf to the end point of the picking operation. In the present embodiment, the component-shelf-distance information table is stored assuming that the arrangement of the component shelves is fixed. However, in the case of changing the arrangement of the component shelves, the present invention can be applied by updating the component-shelf-distance information table. 
         [0030]    The component-shelf-layout information storage area  114  stores information specifying a component-shelf layout. In the present invention, the component-shelf layout does not describe arranged locations or an arrangement form of the component shelves, but means specifying which component is allocated to each component shelf. For example, a component-shelf-layout information table shown in  FIG. 7  is stored in the present embodiment. As shown in  FIG. 7 , the component-shelf-layout information table includes a layout-name column  114   a , a shelf-name column  114   b , an allocated-component-name column  114   c , a replenishment-point column  114   d , and a replenishment-amount column  114   e . The layout-name column  114   a  stores information specifying the name of a component-shelf layout. The shelf-name column  114   b  stores information specifying a component-shelf name. The allocated-component-name column  114   c  stores information specifying the name of the component allocated to the corresponding component shelf. The replenishment-point column  114   d  and the replenishment-amount column  114   e  are related to the capacity of the component shelf and, when a component is allocated to that component shelf, store information specifying the replenishment point and the replenishment amount of that component on the corresponding component shelf. 
         [0031]    The component-shelf-layout change information storage area  115  stores information specifying a change of component allocation when a layout is changed to another layout, which is a processing result of a component-shelf-layout change extraction unit described later. For example, a component-shelf-layout change information table shown in  FIG. 8  is stored in the present embodiment. As shown in  FIG. 8 , the component-shelf-layout change information table includes a pre-change layout-name column  115   a , a changed layout-name column  115   b , a component-name column  115   c , a pre-changed allocated-shelf-name column  115   d , a changed allocated-shelf-name column  115   e , a changed replenishment-point column  115   f , and a changed replenishment-amount column  115   g . The pre-changed layout-name column  115   a  and the changed layout-name column  115   b  store information specifying the names of component-shelf layouts before and after being changed. The component-name column  115   c  stores information specifying a component name. The pre-changed allocated-shelf-name column  115   d  stores information specifying the name of a component shelf to which the corresponding component is allocated in the corresponding pre-changed layout. The changed allocated-shelf-name column  115   e  stores information specifying the name of a component shelf to which the corresponding component is allocated in the corresponding changed layout. The changed replenishment-point column  115   f  and the changed replenishment-amount column  115   g  store information specifying the replenishment point and the replenishment amount of the corresponding component on the corresponding component shelf in the corresponding changed layout. 
         [0032]    The picking-operation information storage area  116  stores information specifying the movement distance of each round in the picking operation, which is a processing result of a picking-movement distance calculation unit described later. For example, a picking-operation information table shown in  FIG. 9  is stored in the present embodiment. As shown in  FIG. 9 , the picking-operation information table includes a round-number column  116   a  and a movement-distance column  116   b . The round-number column  116   a  stores information specifying a round number. The movement-distance column  116   b  stores information specifying the movement distance in the corresponding round. 
         [0033]    The replenishment-operation information storage area  117  stores information specifying the number of occurrences of a replenishment operation of each component in each day, which is a processing result of a replenishment-occurrence frequency calculation unit described later. For example, a replenishment-operation information table shown in  FIG. 10  is stored in the present embodiment. The replenishment-operation information table includes a date column  117   a , a component-name column  117   b , a shelf-name column  117   c , and a number-of-occurrences-of-replenishment column  117   d , as shown in  FIG. 10 . The date column  117   a  stores information specifying a date. The component-name column  117   b  stores information specifying a component name. The shelf-name column  117   c  stores information specifying a component-shelf name. The number-of-occurrences-of-replenishment column  117   d  stores information specifying the number of occurrences of replenishment of the corresponding component on the corresponding component shelf on the corresponding date. 
         [0034]    The parameter information storage area  118  stores information specifying an item and a value of each parameter for which input is received in a display unit described later. For example, a parameter information table shown in  FIG. 11  is stored in the present embodiment. As shown in  FIG. 11 , the parameter information table includes an item column  118   a  and a value column  118   b . The item column  118   a  stores information specifying a parameter item. The value column  118   b  stores information specifying a value of that item. 
         [0035]    Returning to  FIG. 1 , the control unit  120  includes a new component-shelf layout creation unit  121 , a picking-movement distance calculation unit  122 , a replenishment-occurrence frequency calculation unit  123 , an optimal component-shelf layout extraction unit  124 , and a component-shelf layout change extraction unit  125 . 
         [0036]    The new component-shelf layout creation unit  121  performs a process that uses the component-shelf-layout information, the component/shelf allocation-availability information, and the component-shelf-distance information in the storage unit  110  to create a new component-shelf layout proposal. In the present embodiment, for example, the new component-shelf layout proposal is created by using current or new component-shelf-layout information and replacing component shelves of any of the two components. Information on the created component-shelf layout proposal is stored in new component-shelf-layout information. 
         [0037]    The picking-movement distance calculation unit  122  performs a process that uses the picking-operation-results information, the component-shelf-distance information, and the component-shelf-layout information in the storage unit  110  to calculate a picking-movement distance in each component-shelf layout. The details of this process will be described later. 
         [0038]    The replenishment-occurrence frequency calculation unit  123  performs a process that uses the picking-operation-results information and the component-shelf-layout information in the storage unit  110  to calculate an occurrence frequency of the replenishment operation in each component-shelf layout. The details of this processing will be described later. 
         [0039]    The optimal component-shelf layout extraction unit  124  performs a process that uses the picking operation information and the replenishment operation information in the storage unit  110  to extract an optical component-shelf layout from the component-shelf layout proposals created by the new component-shelf layout creation unit. The details of this process will be described later. 
         [0040]    The component-shelf layout change extraction unit  125  performs a process that uses the component-shelf layout extracted by the optimal component-shelf layout extraction unit  124  to extract a layout change when the current component-shelf layout is changed to an optimal component-shelf layout. The details of this process will be described later. 
         [0041]    Returning to  FIG. 1 , the display unit  130  outputs information in the storage unit  110 . For example, the display unit  130  performs a process that displays the information in the component-shelf-layout change information storage area  115  of the storage unit  110 . The communication unit  140  performs transmission and reception of information via a network. 
         [0042]      FIG. 2  is a schematic diagram of a component-shelf-layout design system according to an embodiment of the present invention. As shown in  FIG. 2 , the component-shelf-layout design system includes the component-shelf-layout design device  210 , a picking-operation-results management device  220 , and a component-shelf-layout change instruction device  230 . These devices can transmit/receive information mutually via a network  240 . 
         [0043]    The picking-operation-results management device  220  receives input from an information terminal used in a picking operation and manages information on the result of the picking operation. Also, the picking-operation-results management device  220  transmits picking-operation-results information to the component-shelf-layout design device  210  at a predetermined time or in response to a request from the component-shelf-layout design device  210 . The component-shelf-layout design device  210  stores this information in the picking-operation-results information storage area  111 . 
         [0044]    The component-shelf-layout change instruction device  230  manages information on an allocation change instruction for each component to each component shelf. The component-shelf-layout change instruction device  230  receives the information in the component-shelf-layout change information storage area  115  from the component-shelf-layout design device  210  at a predetermined time or in response to a request from the component-shelf-layout design device  210 . 
         [0045]      FIG. 12  is an example of a process flowchart of the component-shelf-layout design device. The details of the embodiment of the present invention are described below, referring to  FIG. 12 . 
         [0046]    In Step S 100 , results information of each round, used for evaluation of a component-shelf layout, is extracted from the picking-operation-results information table in  FIG. 4 . More specifically, a value of the operation date-and-time column  111   d  of the picking-operation-results information table in  FIG. 4  is extracted as the results information of the round include in a start date and an end date of an evaluated object in the parameter information table in  FIG. 11 . 
         [0047]    In Step S 200 , a current component-shelf layout L 0  is acquired from the component-shelf-layout information table in  FIG. 7 . 
         [0048]    In Step S 300 , the picking-movement distance and the replenishment-occurrence frequency are calculated in the component-shelf layout L 0 . The process of calculating the picking-movement distance is a process by the picking-movement distance calculation unit  122  of the control unit  120 . In calculation of the picking-movement distance, for each round extracted in Step S 100 , a group of component shelves to be traveled is extracted based on components to be picked in that round and the component-shelf layout L 0  first. Then, the order of traveling the group of component shelves is determined, and the movement distance is calculated from the order of traveling and the component-shelf-distance information. Finally, a calculated value is stored in the picking-operation information table in  FIG. 9  as the movement distance of that round. Note that an example of a method that determines the order of traveling the group of component shelves is a method that sequentially selects a shelf to be visited, for example, by visiting Shelf 1  as the first component shelf which is the closest component to the picking start point, then visiting Shelf 2  which is the closest component shelf to Shelf 1 , and so on. Another example is a method in which an initial proposal of the visiting order is set and a visiting order that minimizes the movement distance is searched by successively changing the order in the initial proposal. However, the present invention is not limited to the above-described methods. 
         [0049]    Calculation of the replenishment-occurrence frequency is a process by the replenishment-occurrence frequency calculation unit  123  of the control unit  120 . In the calculation of the replenishment-occurrence frequency, transition of component stock on a component shelf with time is simulated using the delivery amount of each component at each date and time extracted in Step S 100 . During the simulation, it is assumed that when the component stock is below the replenishment point, the replenishment operation occurs, and the component stock is increased to the replenishment amount. By the above process, the number of occurrences of the replenishment operation is counted. The result of the process is stored in the replenishment-operation information table in  FIG. 10 . 
         [0050]    The processes in Step S 400  and S 500  are repeated from a value 1 of a counter n to a value N. Step S 400  is a process by the new component-shelf layout creation unit  121  of the control unit  120  and creates a new component-shelf layout. More specifically, a component-shelf layout L n  is created by changing a portion of the component-shelf layouts L 0  to L n-1 . The following two methods may be used as a changing method, for example. Either one of them may be used, or both may be applied alternately. 
         [0051]    (1) For two components X and Y, component shelves to which they are allocated are replaced with each other, wherein a daily delivery amount is larger for the component X than for the component Y and the replenishment amount is larger for the component Y than for the component X. 
         [0052]    (2) For two components X and Y, the component shelves to which they are allocated are replaced with each other, wherein the daily delivery amount is larger for the component X than for the component Y and a distance from the picking start point is smaller for the component Y than for the component X. 
         [0053]    Note that the component/shelf allocation-availability information is referred to in the above process, and a restriction is provided to exclude a combination of a component and a component shelf for which allocation is not available. The number of created new component-shelf layouts is determined by predetermining the value for N or predetermining an upper limit of a calculation time. A condition other than the above can be added, for example, in which components simultaneously ordered are arranged at close positions to each other. 
         [0054]    In Step S 500 , the picking-movement distance and the number of occurrences of replenishment are calculated for the component-shelf layout L n  created in Step S 104 . The details of this process are the same as those in Step S 300 , and therefore the description thereof is omitted. 
         [0055]    In Step S 600 , an optimal component-shelf layout L Opt  is extracted from the component-shelf layouts L 0  to L N . Examples of an extraction method are a method that extracts a component-shelf layout minimizing the weighted sum of the picking-movement distance and the number of occurrences of replenishment, a method that extracts a component-shelf layout providing the picking-movement distance equal to or smaller than a threshold value and minimizing the number of occurrences of replenishment, and a method that extracts a component-shelf layout providing the number of occurrences of replenishment equal to or smaller than a threshold value and minimizing the picking-movement distance. A user can set each extracting condition and each threshold value. 
         [0056]    In Step S 700 , a layout change is extracted when the current component-shelf layout L 0  is changed to the optimal component-shelf layout L Opt . This process is a process by the component-shelf-layout change extraction unit  125  of the control unit  120 . In this process, a group of components for which allocated component shelves are different between the layouts L 0  and L Opt  is extracted, and information on the component-shelf names before and after the layout change for that group of components is stored in the component-shelf-layout change information table. 
         [0057]      FIGS. 13 and 14  are schematic diagrams of examples of a display screen.  FIG. 13  is an input/display screen for setting information to be stored in the storage unit  110 . This screen includes data-file-path input/display regions  131  and parameter input/display regions  132 . Data created by a user or data stored in an external storage device is imported as picking-operation results data, component/shelf allocation-availability data, component-shelf-distance data, and current component-shelf-layout data. As the picking-operation-results data, not only past results data but also future prediction data can be imported. As the parameter, it is possible to specify a period to be evaluated. The period to be evaluated can be specified by considering a frequency of changing the layout.  FIG. 14  is a display screen for displaying the information in the picking-operation information storage area  111 , the replenishment-operation information storage area  117 , and the component-shelf-layout change storage area  115  in the storage unit  120 . This screen includes a layout-evaluation-result display region  133  for displaying an evaluation result of the picking-movement distance and the number of occurrences of replenishment for each layout proposal, and a component-shelf-layout change display region  134  for displaying a changed point in changing the current layout to the optimal layout. Also, when each point on the layout-evaluation-result display screen is selected, this display screen may be configured to display a change for achieving the layout corresponding to that selected point in the component-shelf-layout change display region. 
         [0058]    In the present embodiment, evaluation values of the movement distance and the number of occurrences of replenishment in each component-shelf layout proposal are calculated using past picking operation results. However, instead of the past picking operation results, a delivery amount of each product in each future round is predicted and the above evaluation values can be calculated using the prediction result. 
         [0059]    In the present embodiment, the picking-movement distance is described as the evaluation value. However, the picking-movement distance calculation unit  122  can convert the picking-movement distance to a picking-operation time by using information on a movement rate of an operator, information on an operation time when the operator picks up each product from each component shelf, and the like. Similarly, as for the number of occurrences of replenishment, the replenishment-occurrence frequency calculation unit  123  can convert the number of occurrences of replenishment to a replenishment-operation time by using information on an operation time required for replenishment of each product onto each product shelf. Then, the optimal component-shelf layout extraction unit  124  can extract the component-shelf layout proposal that can reduce the picking-operation time and the replenishment-operation time as compared with the current component-shelf layout or a component-shelf layout proposal that can minimize the total time. 
         [0060]    In addition, each of the configuration, the functions, the control unit, the storage unit described above, for example, can be partly or entirely implemented by hardware by being designed with an integrated circuit, for example. Furthermore, a processor can interpret and execute a program achieving each of the functions, so that the configuration and the functions described above, for example, can be implemented by software. Information such as a program for achieving each function, a table, and a file can be placed in a storage device, such as a memory, a hard disk drive, or an SSD (Solid State Drive), or a storage medium, such as an IC card, an SD card, or a DVD.