Patent Publication Number: US-2019188634-A1

Title: Stock management device, item sales system and stock management method

Description:
TECHNICAL FIELD 
     The present disclosure relates to a stock management device, an item sales system, a stock management method, and a recording medium. 
     BACKGROUND ART 
     There are an increasing use of online shopping to purchase an item through the Internet. Further, an item sales method called a mobile supermarket using a mobile sales vehicle has been proposed (NPL 1). 
     As a technology of combining the above, a technology of ordering, through a network, an item being sold by a mobile sales vehicle and purchasing the ordered item at a mobile sales vehicle is disclosed (PTL 1 and PTL 2). 
     Further, as a technology related to online shopping, for example, a method of supporting in-store picking of an item to be ordered is described in PTL 3. 
     Further, a technology of managing stock items in a plurality of distribution centers and stock items in a plurality of stores, and delivering an item ordered by a customer to the customer from a distribution center or a store having the item in stock and also being closest to a delivery address is described in PTL 4. 
     Further, a method of recommending another menu when a menu item is out of stock is described in PTL 5. 
     CITATION LIST 
     Patent Literature 
     PTL 1: Japanese Unexamined Patent Application Publication No. 2011-221984 
     PTL 2: Japanese Unexamined Patent Application Publication No. 2008-123278 
     PTL 3: Japanese Unexamined Patent Application Publication No. 2009-151623 
     PTL 4: Japanese Unexamined Patent Application Publication No. 1996-147374 
     PTL 5: Japanese Unexamined Patent Application Publication No. 2014-160305 
     Non Patent Literature 
     NPL 1: “Mobile Supermarket Tokushimaru,” [online], [retrieved on Jul. 13, 2016], retrieved from the Internet: &lt;http://www.tokushimaru.jp/&gt; 
     SUMMARY OF INVENTION 
     Technical Problem 
     Item purchase by online shopping takes at least several hours from ordering of an item to delivery to the purchaser, and therefore it takes a long time for actual delivery after ordering. However, in the case of item purchase by online shopping, for example, there is a benefit that a customer staying indoors can receive an item without going outdoors. Further, selling by a mobile sales vehicle, items are displayed on a luggage carrier of the mobile sales vehicle as is the case with a common supermarket, and therefore a customer can actually take an item in hand and purchase the item at the mobile sales vehicle. Accordingly, for example, when a supermarket does not exist close to a customer and a mobile sales vehicle sells items close to the customer, there is a benefit that the customer can get an item to be purchased at a storefront of the mobile sales vehicle, without visiting a distant supermarket. A technology allowing a customer to acquire both such a benefit of online shopping and such a benefit by using a mobile sales vehicle is being sought. In order to acquire both of the benefits, the present inventors have found a method of unitarily managing stock of items being sold at a mobile sales vehicle and stock of items being sold on online shop. However, by unitarily managing the stock of items, when an item of which a customer doing online shopping wants to purchase is being sold at a mobile sales vehicle to be delivering the item to the customer, the item may be purchased by another customer using the mobile sales vehicle. 
     An object of the present disclosure is to provide a technology being capable of providing both a benefit of online shopping and a benefit by using a mobile sales vehicle, and also being capable of delivering, to a customer doing online shopping, an item which the customer wants, even when the item is purchased at a mobile sales vehicle. 
     Solution to Problem 
     A stock management device according to one aspect of the present disclosure includes: 
     management means for managing stock information about stock of an item held by each of a plurality of mobile sales vehicles; 
     first reception means for receiving, from each of the plurality of mobile sales vehicles, sales information indicating an item sold at a storefront of the mobile sales vehicle; 
     second reception means for receiving, from a customer terminal, order information including information about an item ordered based on the stock information transmitted to the customer terminal; 
     transmission means for transmitting the order information to the mobile sales vehicle holding the ordered item included in the order information; and 
     detection means for detecting the item included in the order information becoming out-of-stock at the storefront of the mobile sales vehicle to which the order information has been transmitted, before the item is delivered to a delivery address, wherein, 
     when the item becoming out-of-stock is detected by the detection means, the transmission means transmits the order information to another mobile sales vehicle holding the ordered item included in the order information and being different from the mobile sales vehicle to which the order information has been transmitted, and 
     the management means updates the stock information based on at least one of the sales information and the order information. 
     An item sales system according to one aspect of the present disclosure includes: 
     a stock management device; 
     an on-board device being loaded on each of a plurality of mobile sales vehicles and transmitting, to the stock management device, sales information indicating an item sold at a storefront of each of the plurality of mobile sales vehicles; and 
     one or more customer terminals, wherein 
     the stock management device includes:
         management means for managing stock information about stock of an item held by each of the plurality of mobile sales vehicles;   first reception means for receiving the sales information from each of the plurality of mobile sales vehicles;   second reception means for receiving, from the customer terminal, order information including information about an item ordered based on the stock information transmitted to the customer terminal;   transmission means for transmitting the order information to the mobile sales vehicle holding the ordered item included in the order information; and   detection means for detecting the item included in the order information becoming out-of-stock at a storefront of the mobile sales vehicle to which the order information has been transmitted, before the item is delivered to a delivery address, wherein,       

     when the item becoming out-of-stock is detected by the detection means, the transmission means transmits the order information to another mobile sales vehicle holding the ordered item included in the order information and being different from a mobile sales vehicle to which the order information has been transmitted, and 
     the management means updates the stock information, based on at least one of the sales information and the order information. 
     A stock management method according to one aspect of the present disclosure includes: 
     managing stock information about stock of an item held by each of a plurality of mobile sales vehicles; 
     receiving, from each of the plurality of mobile sales vehicles, sales information indicating an item sold at a storefront of the mobile sales vehicle; 
     receiving, from a customer terminal, order information including information about an item ordered based on the stock information transmitted to the customer terminal; 
     transmitting the order information to the mobile sales vehicle holding the ordered item included in the order information; and 
     detecting the item included in the order information becoming out-of-stock at the storefront of the mobile sales vehicle to which the order information has been transmitted, before the item is delivered to a delivery address, wherein, 
     when the item becoming out-of-stock is detected, transmitting the order information to another mobile sales vehicle holding the ordered item included in the order information and being different from the mobile sales vehicle to which the order information has been transmitted, and 
     updating the stock information based on at least one of the sales information and the order information. 
     A stock management method in an item sales system including a stock management device, an on-board device loaded on each of a plurality of mobile sales vehicles, and one or more customer terminals, the stock management method according to one aspect of the present disclosure includes: 
     managing, by the stock management device, stock information about stock of an item held by each of the plurality of mobile sales vehicles; 
     transmitting, by the on-board device, to the stock management device, sales information indicating an item sold at a storefront of a mobile sales vehicle loaded with the on-board device; 
     transmitting, by the customer terminal, to the stock management device, order information including information about an item ordered based on the stock information received from the stock management device; 
     receiving, by the stock management device, the sales information from the on-board device; 
     receiving, by the stock management device, the order information from the customer terminal; 
     transmitting, by the stock management device, the order information to the mobile sales vehicle holding the ordered item included in the order information; and 
     detecting, by the stock management device, the item included in the order information becoming out-of-stock at the storefront of the mobile sales vehicle to which the order information has been transmitted, before the item is delivered to a delivery address, wherein, 
     when the item becoming out-of-stock is detected, transmitting, by the stock management device, the order information to another mobile sales vehicle holding the ordered item included in the order information and being different from the mobile sales vehicle to which the order information has been transmitted, and 
     updating, by the stock management device, the stock information based on at least one of the sales information and the order information. 
     A computer program implementing the respective devices, the system, or the methods described above with a computer, and a computer-readable non-transitory recording medium storing the computer program are also included in the scope of the present disclosure. 
     Advantageous Effects of Invention 
     The present disclosure can provide both a benefit of online shopping and a benefit by using a mobile sales vehicle, and can also deliver, to a customer doing online shopping, an item which the customer wants, even when the item is purchased at a mobile sales vehicle. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a functional block diagram illustrating a functional configuration example of a stock management device according to a first example embodiment. 
         FIG. 2  is a flowchart illustrating an example of a processing flow in the stock management device according to the first example embodiment. 
         FIG. 3  is a functional block diagram illustrating a functional configuration example of an item sales system including the stock management device according to the first example embodiment. 
         FIG. 4  is a flowchart illustrating an example of a processing flow in the item sales system including the stock management device according to the first example embodiment. 
         FIG. 5  is a block diagram illustrating a configuration example of an item sales system according to a second example embodiment. 
         FIG. 6  is a diagram for illustrating a use scene of the item sales system according to the second example embodiment. 
         FIG. 7  is a functional block diagram illustrating a functional configuration example of a stock management device in the item sales system according to the second example embodiment. 
         FIG. 8  is a diagram illustrating an example of stock information stored by a stock information storage unit according to the second example embodiment. 
         FIG. 9  is a diagram illustrating an example of customer information stored by a customer information storage unit according to the second example embodiment. 
         FIG. 10  is a functional block diagram illustrating a functional configuration example of an on-board device in the item sales system according to the second example embodiment. 
         FIG. 11  is a functional block diagram illustrating a functional configuration example of a customer terminal in the item sales system according to the second example embodiment. 
         FIG. 12  is a diagram illustrating an example of an ordering screen displayed by a display unit. 
         FIG. 13  is a flowchart illustrating an example of a processing flow of updating stock information, based on sales information, in the item sales system according to the second example embodiment. 
         FIG. 14  is a flowchart illustrating an example of a flow of transmission processing of present position information by the on-board device in the item sales system according to the second example embodiment. 
         FIG. 15  is a flowchart illustrating an example of a flow of sales processing of an item by online shopping in the item sales system according to the second example embodiment. 
         FIG. 16  is a flowchart illustrating an example of a flow of the sales processing of items by online shopping in the item sales system according to the second example embodiment. 
         FIG. 17  is a diagram exemplarily illustrating a hardware configuration of a computer (information processing device) capable of implementing the respective example embodiments. 
     
    
    
     EXAMPLE EMBODIMENT 
     First Example Embodiment 
     A first example embodiment of the present disclosure will be described with reference to drawings. A stock management device  10  managing stock information about stock of an item held by each of a plurality of mobile sales vehicles will be described in the present example embodiment. A mobile sales vehicle is a vehicle capable of moving to a predetermined location in accordance with a predetermined traveling route or in a predetermined area, and selling items loaded on a luggage carrier of the vehicle, at the destination. A mobile sales vehicle can also receive an order for an item loaded on the vehicle, while opening a luggage carrier and selling items loaded on the luggage carrier, or through a network while moving. Then, based on the received order, the mobile sales vehicle delivers the item to a customer who ordered. Thus, a mobile sales vehicle sells an item loaded on the mobile sales vehicle not only at its storefront but also through a network. Therefore, competition for sale of items displayed at the storefront may occur between sale at the storefront and sale through a network. In the present disclosure, a technology capable of providing both a benefit of online shopping and a benefit by using a mobile sales vehicle, even when competition for sale occurs as described above, will be described.  FIG. 1  is a functional block diagram illustrating a functional configuration example of the stock management device  10  according to the present example embodiment. As illustrated in  FIG. 1 , the stock management device  10  according to the present example embodiment includes a management unit  11 , a first reception unit  12 , a second reception unit  13 , a transmission unit  14  and a detection unit  15 . 
     The management unit  11  manages stock information about stock of an item held by each of a plurality of mobile sales vehicles. The stock information includes at least information (for example, an item name and an item identifier) for identifying an item held by each of the plurality of mobile sales vehicles and a quantity of the item. The management unit  11  manages stock information for each mobile sales vehicle. The stock information managed by the management unit  11  may be stored in a storage unit provided inside the stock management device  10  or may be stored in a storage device separate from the stock management device  10 . 
     Further, the management unit  11  updates stock information, based on sales information received by the first reception unit  12  and/or order information received by the second reception unit  13 . 
     The first reception unit  12  receives, from each of a plurality of mobile sales vehicles, sales information indicating an item sold at a storefront of the mobile sales vehicle. The sales information includes at least information (for example, an item name and an item identifier) for identifying an item sold at a storefront of a mobile sales vehicle, and a quantity of the item. The first reception unit  12  provides the received sales information to the management unit  11 . 
     The second reception unit  13  receives from a customer terminal order information including information about an item ordered based on stock information transmitted to the customer terminal. The stock information may be transmitted by any unit or a component (unillustrated) transmitting the stock information. The order information includes at least information for identifying a customer ordering an item, information (for example, an item name and an item identifier) for identifying the ordered item, the item being included in the stock information managed by the management unit  11 , and a quantity of the item. The second reception unit  13  provides the received order information to the management unit  11 . 
     The transmission unit  14  transmits order information to a mobile sales vehicle holding an ordered item included in the order information. Specifically, the transmission unit  14  receives from the management unit  11  information indicating a mobile sales vehicle holding an ordered item included in order information along with the order information and transmits the order information to the mobile sales vehicle. 
     Further, when the item becoming out-of-stock is detected by the detection unit  15 , the transmission unit  14  transmits order information to another mobile sales vehicle holding the ordered item included in the order information and being different from the mobile sales vehicle to which the order information has been transmitted. Specifically, based on stock information managed by the management unit  11 , the management unit  11  specifies another mobile sales vehicle being different from the mobile sales vehicle to which order information has been transmitted, and holding the item included in the order information. Then, the transmission unit  14  receives information about the specified another mobile sales vehicle from the management unit  11  and transmits the order information to the specified another mobile sales vehicle. 
     The detection unit  15  detects one or more items included in order information becoming out-of-stock at the storefront of the mobile sales vehicle to which the order information has been transmitted by the transmission unit  14 , before the mobile sales vehicle delivers the item to a delivery address. For example, based on sales information, the detection unit  15  provides the management unit  11  with the detection result. Becoming out-of-stock according to the present example embodiment not only includes a case that a stock quantity becomes zero but also includes a case that a quantity of an item at a storefront of the mobile sales vehicle becomes less than a quantity of the item included in order information. 
     Next, a processing flow in the stock management device  10  according to the present example embodiment will be described with reference to  FIG. 2 .  FIG. 2  is a flowchart illustrating an example of the processing flow in the stock management device  10  according to the present example embodiment. It is assumed in  FIG. 2  that the management unit  11  in the stock management device  10  manages stock information about stock of an item held by a plurality of mobile sales vehicles, for each mobile sales vehicle. It is further assumed that the stock management device  10  transmits stock information to a customer terminal. 
     As illustrated in  FIG. 2 , first, the first reception unit  12  in the stock management device  10  receives, from each of a plurality of mobile sales vehicles, sales information indicating an item sold at a storefront of the mobile sales vehicle (Step S 21 ). 
     Further, the second reception unit  13  receives from a customer terminal order information including information about an item ordered based on stock information transmitted to the customer terminal from the stock management device  10  (Step S 22 ). Steps S 21  and S 22  may be performed at a time or in reverse order. Further, the processing in Step S 21  is performed asynchronously with the processing in or after Step S 22 . 
     When Step S 22  ends, the transmission unit  14  transmits the order information received in Step S 22  to a mobile sales vehicle holding the ordered item included in the order information (Step S 23 ). 
     Then, after Step S 23  ends, the detection unit  15  confirms whether or not the mobile sales vehicle to which the order information has been transmitted delivers the item included in the order information to a delivery address (Step S 24 ). When delivery of the item is completed (YES in Step S 24 ), the stock management device  10  advances the processing to Step S 28 . When the delivery is not completed, that is, when the item included in the order information is not yet delivered to the delivery address (NO in Step S 24 ), the stock management device  10  advances the processing to Step S 25 . 
     As described above, the stock management device  10  performs the processing in Step S 21  asynchronously with the processing in and after Step S 23 . Accordingly, in and after Step S 23 , the stock management device  10  receives sales information from the mobile sales vehicle to which the order information has been transmitted. In other words, the aforementioned mobile sales vehicle sells the item at its storefront. Consequently, the item becoming out-of-stock may occur. 
     When there is no item becoming out-of-stock out of one or more items included in the order information at the storefront of the mobile sales vehicle to which the order information has been transmitted (NO in Step S 25 ), the stock management device  10  returns the processing to Step S 24 . When there is an item becoming out-of-stock out of the items included in the order information at the storefront of the mobile sales vehicle to which the order information has been transmitted (YES in Step S 25 ), the detection unit  15  detects the out-of-stock condition of the item (Step S 26 ). 
     Then, the transmission unit  14  transmits the order information to another mobile sales vehicle holding the item included in the order information and being different from the mobile sales vehicle to which the order information has been transmitted in Step S 23  (Step S 27 ). 
     Then, the management unit  11  updates stock information, based on the sales information and/or the order information (Step S 28 ). Specifically, when Step S 21  ends, the management unit  11  updates stock information about stock of items held by the mobile sales vehicle transmitting the sales information, based on the sales information. When updating the stock information based on the order information, the management unit  11  updates stock information about stock of items held by the mobile sales vehicle to which the order information has been transmitted in Step S 23  or S 27 . 
     The above concludes the processing by the stock management device  10 . 
     As described above, the management unit  11  updates stock information, based on at least one of sales information received by the first reception unit  12  and order information received by the second reception unit  13 . The stock management device  10  manages both stock for mobile sale by a mobile sales vehicle and stock for an online shop. Thus, the stock management device  10 , for example, reflects stock for mobile sale in which items sold by mobile sale to stock for an online shop. Further, for example, when an order for an item is placed by an online shop, stock information about stock of items available for sale at a mobile sales vehicle is also updated. Consequently, both a customer using a mobile sales vehicle and a customer doing online shopping can confirm items in stock purchasable at the time. Accordingly, items held by a mobile sales vehicle can be sold both at the mobile sales vehicle and on an online shop. 
     Further, the transmission unit  14  transmits order information to a mobile sales vehicle holding an ordered item included in the order information. Consequently, a driver of a mobile sales vehicle receiving the order information can deliver an item to a customer who ordered the item held by the mobile sales vehicle. 
     Further, when the item included in order information becomes out-of-stock due to the item being sold at the storefront of the mobile sales vehicle receiving the order information before the item has been delivered to the delivery address by the mobile sales vehicle, the detection unit  15  detects the out-of-stock condition of the item. Then, the transmission unit  14  transmits the order information to another mobile sales vehicle different from the mobile sales vehicle to which the order information has been transmitted and holding the item included in the order information. 
     Consequently, a driver of the mobile sales vehicle receiving the order information can deliver the item held by the mobile sales vehicle to a customer placing the order. 
     Accordingly, the stock management device  10  according to the present example embodiment can deliver, to a customer doing online shopping, an item which the customer wants, even when the item is purchased at a mobile sales vehicle. 
     Further, an item sales system  1  including the stock management device  10  according to the present example embodiment will be described with reference to  FIG. 3 .  FIG. 3  is a functional block diagram illustrating a functional configuration example of the item sales system  1  including the stock management device  10  according to the present example embodiment. As illustrated in  FIG. 3 , the item sales system  1  includes a stock management device  10 , a plurality of on-board devices  20 , and one or a plurality of customer terminals  30 . The stock management device  10  included in  FIG. 3  has a configuration similar to that of the stock management device  10  described by use of  FIG. 1 . 
     An on-board device  20  is loaded on each of a plurality of mobile sales vehicles and transmits to the stock management device  10  sales information indicating the item sold at the storefront of each of the plurality of mobile sales vehicles. A first reception unit  12  in the stock management device  10  receives the sales information. 
     Further, a second reception unit  13  in the stock management device  10  receives order information transmitted from each customer terminal  30 . 
     A management unit  11  in the stock management device  10  updates stock information based on at least one of sales information received by the first reception unit  12  and order information received by the second reception unit  13 . 
     Further, a transmission unit  14  transmits order information to an on-board device  20  on a mobile sales vehicle holding an ordered item included in the order information. 
     Further, a detection unit  15  detects the item included in order information becoming out-of-stock at the storefront of the mobile sales vehicle to which the order information has been transmitted by the transmission unit  14 , before the mobile sales vehicle delivers the item to the delivery address. Then, based on the detection result by the detection unit  15 , the transmission unit  14  transmits the order information to another mobile sales vehicle different from the mobile sales vehicle to which the order information has been transmitted. The “another” mobile sales vehicle is a mobile sales vehicle holding the item included in the order information. 
     Next, a processing flow in the item sales system  1  including the stock management device  10  according to the present example embodiment will be described with reference to  FIG. 4 .  FIG. 4  is a flowchart illustrating an example of the processing flow in the item sales system  1  including the stock management device  10  according to the present example embodiment. It is assumed in  FIG. 4  that the management unit  11  in the stock management device  10  manages stock information about stock of an item held by a plurality of mobile sales vehicles, for each mobile sales vehicle. It is further assumed that the stock management device  10  transmits the stock information to a customer terminal  30 . Further, in  FIG. 4 , processing by an on-board device  20  is described on the left, processing by the stock management device  10  at the center, and processing by a customer terminal  30  on the right; and a broken arrow between the respective processing steps represents a flow of primary information. An information flow is not limited to a direction of an arrow, and for example, an ACKnowledgement (ACK) may be transmitted in a direction reverse to the arrow. 
     As indicated in  FIG. 4 , an on-board device  20  transmits to the stock management device  10  sales information indicating an item sold at the storefront of the mobile sales vehicle loaded with the on-board device  20  (Step S 41 ). Further, a customer terminal  30  transmits to the stock management device  10  order information including information about an item ordered based on the stock information received from the stock management device  10  (Step S 42 ). Steps S 41  and S 42  are performed asynchronously, and an order thereof is not particularly limited. 
     When Step S 41  ends, the first reception unit  12  in the stock management device  10  receives sales information indicating an item sold at the storefront from an on-board device  20  loaded on each of a plurality of mobile sales vehicles (Step S 43 ). Further, when Step S 42  ends, the second reception unit  13  in the stock management device  10  receives the order information from the customer terminal  30  (Step S 44 ). 
     When Step S 44  ends, the transmission unit  14  transmits the order information received in Step S 44  to an on-board device  20  loaded on a mobile sales vehicle holding the ordered item included in the order information (Step S 45 ). 
     Then, after Step S 45  ends, the detection unit  15  confirms whether or not the mobile sales vehicle to which the order information has been transmitted has delivered the item included in the order information to the delivery address (Step S 46 ). For example, the detection unit  15  confirms whether or not the mobile sales vehicle has delivered the item to the delivery address based on whether or not a delivery completion notification indicating delivery completion is received from the mobile sales vehicle. When the delivery of the item is completed (YES in Step S 46 ), the stock management device  10  advances the processing to Step S 50 . When the delivery is not completed, that is, when the item included in the order information is not yet delivered to the delivery address (NO in Step S 46 ), the stock management device  10  advances the processing to Step S 47 . When, at the storefront of the mobile sales vehicle to which the order information has been transmitted, there is no item becoming out-of-stock out of items included in the order information (NO in Step S 47 ), the stock management device  10  returns the processing to Step S 46 . When, at the storefront of the mobile sales vehicle to which the order information has been transmitted, there is an item becoming out-of-stock out of the items included in the order information (YES in Step S 47 ), the detection unit  15  detects the out-of-stock condition of the item (Step S 48 ). 
     Then, the transmission unit  14  transmits the order information to another mobile sales vehicle holding the item included in the order information and being different from the mobile sales vehicle to which the order information has been transmitted in Step S 45  (Step S 49 ). 
     Then, the management unit  11  updates the stock information, based on the sales information and/or the order information (Step S 50 ). Specifically, when updating the stock information based on the sales information, the management unit  11  updates the stock information about stock of items held by the mobile sales vehicle transmitting the sales information based on the sales information. When updating the stock information based on the order information, the management unit  11  updates the stock information about stock of items held by the mobile sales vehicle to which the order information has been transmitted in Step S 45  or S 49 . 
     In the item sales system  1 , when an item is purchased at a mobile sales vehicle loaded with an on-board device  20 , Step S 41  is executed again. Further, when an item is ordered by a customer terminal  30 , Step S 42  is executed again. 
     Thus, the stock management device  10  executes the processing illustrated in the flowchart in  FIG. 4  every time a customer purchases an item. 
     As described above, in the item sales system  1 , the management unit  11  in the stock management device  10  updates stock information, based on sales information received by the first reception unit  12  and order information received by the second reception unit  13 . Further, the transmission unit  14  transmits order information to an on-board device  20  on a mobile sales vehicle holding the ordered item included in the order information. Then, when the item included in the order information becomes out-of-stock due to the item being sold at the storefront of the mobile sales vehicle to which the order information has been transmitted, the detection unit  15  detects the out-of-stock condition of the item. Then, the transmission unit  14  transmits the order information to an on-board device  20  on a mobile sales vehicle holding the item included in the order information, the mobile sales vehicle being different from the mobile sales vehicle loaded with the on-board device  20  to which the order information has been transmitted. Consequently, the “another” mobile sales vehicle loaded with the on-board device  20  can deliver the ordered item to a customer ordering the item. 
     Accordingly, the item sales system  1  including the stock management device  10  according to the present example embodiment can deliver, to a customer doing online shopping, an item which the customer wants, even when the item is purchased at a mobile sales vehicle. 
     Second Example Embodiment 
     Next, a second example embodiment of the present disclosure based on the aforementioned first example embodiment will be described with reference to drawings. First,  FIG. 5  illustrates a configuration example of an item sales system  2  according to the present example embodiment. As illustrated in  FIG. 5 , the item sales system  2  according to the present example embodiment includes a stock management device  100 , a plurality of on-board devices  200 , and one or a plurality of customer terminals  300 . The stock management device  100  communicates with on-board devices  200  and customer terminals  300  through a network. A customer terminal  300  may be a mobile terminal or may be a desktop terminal. 
       FIG. 6  is a diagram for illustrating a use scene of the item sales system  2  according to the present example embodiment. An on-board device  200  included in the item sales system  2  is a device loaded on each of a plurality of mobile sales vehicles. While  FIG. 6  illustrates three mobile sales vehicles (SA, SB, SC), a number of mobile sales vehicle has only to be two or more. Further, while an on-board device  200  loaded on the mobile sales vehicle SA is referred to as an on-board device  200 A, an on-board device  200  loaded on the mobile sales vehicle SB is referred to as an on-board device  200 B, and an on-board device  200  loaded on the mobile sales vehicle SC is referred to as an on-board device  200 C, the devices are simply referred to as on-board devices  200  when the devices are not distinguished or referred to by a general name. 
     For example, each of the mobile sales vehicles (SA, SB, SC) is a mobile-type supermarket traveling in accordance with a predetermined traveling route, stopping at a predetermined location, and selling an loaded item to a customer. The mobile sales vehicle may also be referred to as a mobile supermarket. Traveling routes according to which the plurality of mobile sales vehicles (SA, SB, SC) travel may be identical, different, or partially overlapping one another. 
     It is assumed that a user UC is a customer using a mobile sales vehicle, according to the present example embodiment. It is further assumed that a user UA living in a customer house CA is a customer doing online shopping by use of a customer terminal  300 A. It is further assumed that a user UB living in a customer house CB is a customer doing online shopping by use of a customer terminal  300 B. The customer terminal  300 A and the customer terminal  300 B are simply referred to as customer terminals  300  when the terminals are not distinguished or referred to by a general name. The customer house CA and the customer house CB may be houses facing roads on the traveling routes of the mobile sales vehicles (SA, SB, SC) or may be houses within a predetermined range from the traveling routes, respectively. 
     A store providing a service allowing a customer to do online shopping is hereinafter referred to as an online shop. 
     The item sales system  2  according to the present example embodiment provides both a customer using a mobile sales vehicle and a customer doing online shopping with benefits of using the respective means, by the stock management device  100  communicating with an on-board device  200  and a customer terminal  300 . 
     Next, a function of each device in the item sales system  2  according to the present example embodiment will be described in detail.  FIG. 7  is a functional block diagram illustrating a functional configuration example of the stock management device  100  in the item sales system  2  according to the present example embodiment. As illustrated in  FIG. 7 , the stock management device  100  includes a management unit  110 , a first reception unit  120 , a second reception unit  130 , a first transmission unit  140 , a second transmission unit  150 , a stock information storage unit  160 , a customer information storage unit  170 , a detection unit  180  and a specification unit  180 . 
     The stock information storage unit  160  stores stock information being information indicating stock of items held by each of a plurality of mobile sales vehicles. The stock information stored by the stock information storage unit  160  will be described with reference to  FIG. 8 .  FIG. 8  is a diagram illustrating an example of stock information stored by the stock information storage unit  160  according to the present example embodiment. The stock information includes at least an item name being information for identifying an item held by each of a plurality of mobile sales vehicles, and a quantity of an item represented by the item name for each mobile sales vehicle. The stock information may include a unit price, as illustrated in  FIG. 8 . Information included in the stock information is not limited to the above. 
     The customer information storage unit  170  stores customer information indicating information about a customer using a mobile sales vehicle and/or an online shop. The customer information stored by the customer information storage unit  170  will be described with reference to  FIG. 9 .  FIG. 9  is a diagram illustrating an example of customer information stored by the customer information storage unit  170  according to the present example embodiment. The customer information includes a customer IDentifier (ID) for identifying a customer, a name of the customer, an address of the customer, and a telephone number of the customer. The customer information is not limited to the above and may include other information. Further, the customer information has only to include information by which a delivery address of an item can be identified. Further, for example, the customer information may include authentication information used for logging into an online shop. The customer information may be pre-registered when a service provided by the item sales system  2  is used. The registration method of the customer information is not particularly limited. 
     The stock information storage unit  160  and the customer information storage unit  170  may be implemented as separate storage units or may be implemented as the same storage unit. Further, the stock information storage unit  160  and the customer information storage unit  170  may be implemented as a storage device separate from the stock management device  100 . Further, the stock information storage unit  160  and the customer information storage unit  170  may store stock information and customer information as databases, respectively. 
     The first reception unit  120  corresponds to the first reception unit  12  according to the first example embodiment. The first reception unit  120  receives from each of a plurality of mobile sales vehicles sales information indicating an item sold at its storefront. The sales information includes at least information (for example, an item name and an item identifier) for identifying an item sold at the storefront of the mobile sales vehicle and a quantity of the item. It is assumed below that the information for identifying an item is an item name. The first reception unit  120  provides the received sales information to the management unit  110  and the detection unit  180  along with information (referred to as mobile sales vehicle information) indicating a mobile sales vehicle loaded with an on-board device  200  being a source of the sales information. The mobile sales vehicle information may be an identifier for identifying a mobile sales vehicle, a license plate number of the mobile sales vehicle, a vehicle identification number of the mobile sales vehicle, a model name of the mobile sales vehicle, or the like. 
     Additionally, the first reception unit  120  further receives current position information indicating current positions of a plurality of mobile sales vehicles. The first reception unit  120  provides received current position information to the specification unit  190  along with mobile sales vehicle information indicating a mobile sales vehicle loaded with an on-board device  200  transmitting the current position information. 
     The second reception unit  130  corresponds to the second reception unit  13  according to the first example embodiment. The second reception unit  130  receives from a customer terminal  300  order information including information about an item ordered based on stock information transmitted to the customer terminal  300 . The order information includes at least information for identifying a customer ordering an item, information (for example, an item name and an item identifier) for identifying the ordered item, the item being included in stock information managed by the management unit  110 , and a quantity of the item. The second reception unit  130  provides the received order information to the management unit  110  and the specification unit  190 . The order information received by the second reception unit  130  includes delivery address information indicating a delivery address designated by a customer. 
     The management unit  110  corresponds to the management unit  11  according to the first example embodiment. The management unit  110  manages stock information stored in the stock information storage unit  160 . Further, the management unit  110  manages customer information stored in the customer information storage unit  170 . Further, the management unit  110  may manage sales information and order information. The sales information and the order information may be stored and managed in a storage unit in the stock management device  100 . 
     Information about stock items loaded on a mobile sales vehicle is registered in the stock information managed by the management unit  110  before each of a plurality of mobile sales vehicles starts mobile sale and also before the item being purchasable by online shopping. Then, the management unit  110  updates the stock information every time an item is purchased by mobile sale, every time an item is purchased by online shopping, and every time an item is carried in. 
     Further, the management unit  110  acquires, from the stock information storage unit  160 , stock information to be transmitted to a customer terminal and provides the acquired stock information to the second transmission unit  150 . At this time, the stock information acquired by the management unit  110  may be stock information about stock held by each of the mobile sales vehicles allowing a customer to purchase the items on an online shop at present, or may be stock information about stock held by mobile sales vehicles positioned within a predetermined range from a customer terminal, based on a position of the customer terminal. The mobile sales vehicle allowing a customer to purchase items on an online shop at present refers to, for example, a mobile sales vehicle capable of selling items on a luggage carrier at present, such as a mobile sales vehicle not being back in a garage, a mobile sales vehicle not all of items running out of stock, or a mobile sales vehicle not ending sale (not on the way back to a garage). Further, the stock information acquired by the management unit  110  may be, for example, stock information about stock held by a mobile sales vehicle positioned within a predetermined range from a delivery address when the delivery address is designated by a customer terminal. Further, the stock information acquired by the management unit  110  may be stock information about stock held by a mobile sales vehicle predesignated by a customer. Thus, the stock information acquired by the management unit  110  is not particularly limited. 
     Further, the management unit  110  updates stock information based on at least one of sales information and order information. For example, when sales information is transmitted from the on-board device  200 A on the mobile sales vehicle SA, the management unit  110  updates stock information about stock of items held by the mobile sales vehicle SA based on the sales information. 
     Further, when the item included in the order information has been delivered to the delivery address by the mobile sales vehicle to which order information has been transmitted, the management unit  110  updates stock information about stock of items held by the mobile sales vehicle, based on the order information. 
     The specification unit  190  receives current position information from the first reception unit  120 . Further, the specification unit  190  receives order information from the second reception unit  130 . The specification unit  190  receives information about one or more mobile sales vehicles holding the item included in the order information from the management unit  110 . Then, the specification unit  190  specifies one or more other mobile sales vehicles different from the mobile sales vehicle to which the first transmission unit  140  transmitted the order information, out of the mobile sales vehicles holding the items included in the order information and being indicated by the information about the mobile sales vehicles received from the management unit  110 . Then, the specification unit  190  specifies one mobile sales vehicle arriving earliest at the delivery address out of the specified other mobile sales vehicles based on current positions of the mobile sales vehicles indicated by the current position information and a position of the delivery address indicated by delivery address information. 
     Furthermore, the specification unit  190  may specify the one mobile sales vehicle in consideration of information indicating whether or not a mobile sales vehicle is open for business, a storefront sales schedule, scheduled traveling route information, or the like. A mobile sales vehicle being open for business represents a state in which the mobile sales vehicle stops at a predetermined location, a loading platform is opened, and an item loaded on the mobile sales vehicle is ready to be sold to a customer. For example, the information indicating whether or not a mobile sales vehicle is open for business may be based on a signal indicating that a loading platform of the mobile sales vehicle is opened, the signal being transmitted from an on-board device  200  to the stock management device  100 . Further, a storefront sales schedule indicates where and when a mobile sales vehicle is scheduled to perform mobile sale. The storefront sales schedule may be stored inside the stock management device  100  or may be transmitted from an on-board device  200 . Further, scheduled traveling route information is information indicating a route on which a mobile sales vehicle is scheduled to travel. The scheduled traveling route information may be stored inside the stock management device  100  or may be transmitted from an on-board device  200 . Further, the specification unit  190  may specify the one mobile sales vehicle in consideration of a traveling direction of a mobile sales vehicle, road information at that point in time, and the like. The traveling direction of a mobile sales vehicle and the road information may be transmitted from an on-board device  200 . The road information may be information indicating a traffic jam or may be information preset to a road, such as one-way traffic. Further, the road information may be transmitted from an external server managing road information. The specification unit  190  provides the first transmission unit  140  with information indicating the specified one mobile sales vehicle. 
     The detection unit  180  corresponds to the detection unit  15  according to the first example embodiment. The detection unit  180  detects the item becoming out-of-stock at the storefront of the mobile sales vehicle to which order information has been transmitted by the first transmission unit  140 . The item detected becoming out-of-stock is the item included in the order information. The detection unit  180  detects the item becoming out-of-stock before the item is delivered to the delivery address. The method of detecting the item becoming out-of-stock at the storefront of the mobile sales vehicle by the detection unit  180  may be, for example, a method based on sales information received by the first reception unit  120 . For example, the detection unit  180  may detect an item becoming out-of-stock by acquiring, from the stock information storage unit  160  through the management unit  110 , stock information about stock of items held by a mobile sales vehicle loaded with an on-board device  200  transmitting sales information, and comparing the acquired quantity of stock items with a quantity of items included in the sales information. According to the present example embodiment, becoming out-of-stock includes not only a case that a stock quantity becomes zero but also includes a case that the stock quantity becomes less than a quantity of items included in order information at a storefront of a mobile sales vehicle. In this case, the detection unit  180  may detect items becoming out-of-stock by use of a quantity of stock items, a quantity of items included in sales information, and a quantity of items included in the order information. The detection unit  180  provides the management unit  110  with the detection result. 
     The first transmission unit  140  corresponds to the transmission unit  14  according to the first example embodiment. The first transmission unit  140  receives, from the management unit  110 , information indicating a mobile sales vehicle holding an ordered item included in order information along with the order information, and transmits the order information to an on-board device  200  loaded on the mobile sales vehicle. 
     Further, when an item becoming out-of-stock is detected by the detection unit  180 , the first transmission unit  140  transmits order information to another mobile sales vehicle holding the ordered item included in the order information and being different from a mobile sales vehicle to which the order information has been transmitted. Specifically, the first transmission unit  140  receives information about another mobile sales vehicle specified by the specification unit  190  from the specification unit  190 . Then, the first transmission unit  140  transmits order information to an on-board device  200  loaded on the specified another mobile sales vehicle indicated by the received information about the specified another mobile sales vehicle. The first transmission unit  140  may transmit, to the specified another mobile sales vehicle, only order information about the out-of-stock item in the order information. 
     Further, when transmitting order information to another mobile sales vehicle, the first transmission unit  140  may transmit an instruction to cancel the order information to the mobile sales vehicle to which the order information has been transmitted. When transmitting, to the specified another mobile sales vehicle, only order information about an out-of-stock item in the order information, the first transmission unit  140  may transmit an instruction to cancel only the order information about the out-of-stock item to the mobile sales vehicle to which the order information has been transmitted. 
     The second transmission unit  150  receives stock information from the management unit  110 . The second transmission unit  150  transmits the stock information to a customer terminal  300 . For example, when a browser is activated on a customer terminal  300 , the second transmission unit  150  may generate a screen including stock information and transmit the generated screen to the customer terminal  300 . Further, for example, when an application is activated on a customer terminal  300 , the second transmission unit  150  may transmit information including stock information to the customer terminal  300  in such a way that the application can display a screen including the stock information. When a customer terminal  300  can display a screen including stock information, the second transmission unit  150  may transmit stock information itself acquired by the management unit  110 . It is preferable that a timing when the second transmission unit  150  transmits stock information to a customer terminal  300  be after detecting that a customer performs an operation for purchasing an item by use of the customer terminal  300 . For example, detecting that a customer performs an operation for purchasing an item by use of the customer terminal  300  includes detecting that the stock management device  100  has received login information from a customer terminal  300  by the customer inputting the login information to the customer terminal  300  for logging into an online shop. Consequently, the customer using the customer terminal  300  can confirm stock information at a timing of logging into the online shop. 
     Further, every time stock information is updated, the second transmission unit  150  may further transmit the updated stock information to a customer terminal  300 . Consequently, a customer using the customer terminal  300  can confirm latest stock information at a time of an update. 
     Next, a functional configuration of an on-board device  200  will be described with reference to  FIG. 10 .  FIG. 10  is a functional block diagram illustrating a functional configuration example of an on-board device  200  in the item sales system  2  according to the present example embodiment. The on-board device  200  includes a sales information acceptance unit  210 , a transmission unit  220 , a positioning unit  230 , and a reception unit  240 . 
     The sales information acceptance unit  210  accepts sales information including an item name of an item sold by a mobile sale (an item purchased by a customer) of a mobile sales vehicle loaded with the on-board device  200 , and a quantity of the item. For example, the sales information acceptance unit  210  is implemented with a point of sales (POS) register. The sales information acceptance unit  210  provides the accepted sales information to the transmission unit  220 . 
     For example, the positioning unit  230  receives positional information by use of the Global Positioning System (GPS), and from the received positional information, measures a current position of a mobile sales vehicle loaded with the on-board device  200 . A means used for measurement of a current position is not limited to the GPS. The positioning unit  230  may measure a current position by use of other information. The positioning unit  230  provides information (current position information) indicating a current position being a measurement result to the transmission unit  220 . 
     When receiving sales information from the sales information acceptance unit  210 , the transmission unit  220  transmits the sales information to the stock management device  100 . Further, when receiving current position information from the positioning unit  230 , the transmission unit  220  transmits the current position information to the stock management device  100 . 
     Further, when the item included in order information has been delivered to the delivery address, the transmission unit  220  transmits a notification that delivery is completed (referred to as a delivery completion notification) to the stock management device  100 . 
     The reception unit  240  receives order information transmitted from the stock management device  100 . Consequently, a mobile sales vehicle loaded with the on-board device  200  receiving the order information can deliver the ordered item to the delivery address indicated by delivery address information, based on the order information. Further, when receiving an instruction to cancel order information with respect to received order information, the reception unit  240  cancels the order information. Consequently, the mobile sales vehicle loaded with the on-board device  200  does not perform delivery based on the cancelled order information. Accordingly, only the mobile sales vehicle receiving the order information can deliver the item included in the order information to the delivery address. 
     Next, a functional configuration of a customer terminal  300  will be described with reference to  FIG. 11 .  FIG. 11  is a functional block diagram illustrating a functional configuration example of a customer terminal  300  in the item sales system  2  according to the present example embodiment. As illustrated in  FIG. 11 , the customer terminal  300  includes a reception unit  310 , a control unit  320 , a display unit  330 , an acceptance unit  340 , and a transmission unit  350 . 
     The reception unit  310  receives stock information from the stock management device  100 . The stock information has only to include information required for displaying information about stock of an item held by a mobile sales vehicle on the display unit  330  and may be, for example, the stock information itself stored in the stock information storage unit  160 , part of the stock information, or processed stock information. The reception unit  310  provides the received stock information to the control unit  320 . 
     The display unit  330  displays a screen in accordance with an instruction by the control unit  320 . For example, the display unit  330  is implemented with a liquid crystal display. The display unit  330  may be implemented with a display device separate from the customer terminal  300 . 
     The acceptance unit  340  accepts an instruction from a user using the customer terminal  300 . For example, the acceptance unit  340  accepts an instruction from a user input through an input device such as a mouse or a keyboard. The acceptance unit  340  provides the accepted instruction to the control unit  320 . 
     The acceptance unit  340  and the display unit  330  may be integrally formed as a touch panel. 
     The control unit  320  controls the display unit  330  to display a screen based on the stock information received by the reception unit  310 . A screen based on the stock information, the control unit  320  controlling the display unit  330  to display the screen, will be described with reference to  FIG. 12 .  FIG. 12  is a diagram illustrating an example of a screen (ordering screen) displayed by the display unit  330 . 
     An ordering screen illustrated in  FIG. 12  displays information about items included in the stock information illustrated in  FIG. 8 . Thus, the control unit  320  causes the display unit  330  to display a screen (ordering screen) based on stock information. 
     An “ADD TO CART” button in  FIG. 12  is a button for accepting an instruction to add a relevant item to a cart on an online shop. In accordance with the instruction, the control unit  320  keeps information of the item added to the cart as cart information. The cart information includes information for identifying an item and a quantity of the item. 
     A “PROCEED TO PAYMENT SCREEN” button in  FIG. 12  is a button for transition to a screen for making payment. A payment method can be selected on the payment screen. The payment method is not particularly limited, and therefore description is omitted in the present example embodiment. When an instruction to make payment is input, the acceptance unit  340  accepts the instruction. Then, in accordance with the instruction to make payment (that is, an instruction that the shopping is finished), the control unit  320  provides information kept as cart information and information for identifying a customer to the transmission unit  350  as order information. 
     When receiving order information from the control unit  320 , the transmission unit  350  transmits the order information to the stock management device  100 . 
     Next, processing of updating stock information, based on sales information, in the item sales system  2  will be described with reference to  FIG. 13 .  FIG. 13  is a flowchart illustrating an example of a flow of the processing of updating stock information, based on sales information, in the item sales system  2  according to the present example embodiment. 
     It is assumed in  FIG. 13  that the management unit  110  in the stock management device  100  manages stock information about stock of an item held by a plurality of mobile sales vehicles, for each mobile sales vehicle. Further, in  FIG. 13 , processing by an on-board device  200  is described on the left and processing by the stock management device  100  on the right; and a broken arrow between the respective processing steps represents a flow of primary information. An information flow is not limited to a direction of an arrow, and for example, an ACK may be transmitted in a direction reverse to the arrow. 
     First, the sales information acceptance unit  210  in the on-board device  200  accepts sales information including an item name of an item sold by a mobile sale (an item purchased by a customer) of a mobile sales vehicle loaded with the on-board device  200 , and a quantity of the item (Step S 131 ). Then, the transmission unit  220  transmits the sales information to the stock management device  100  (Step S 132 ). 
     The first reception unit  120  in the stock management device  100  receives the sales information transmitted from the on-board device  200  (Step S 133 ). The first reception unit  120  provides the sales information to the management unit  110  along with mobile sales vehicle information. 
     Based on the sales information provided from the first reception unit  120 , the management unit  110  updates stock information about stock held by the mobile sales vehicle specified by the mobile sales vehicle information transmitted along with the sales information (Step S 134 ). 
     The above concludes the processing of updating stock information based on sales information. 
     Next, transmission processing of current position information by an on-board device  200  will be described with reference to  FIG. 14 .  FIG. 14  is a flowchart illustrating an example of a flow of the transmission processing of current position information by an on-board device  200  in the item sales system  2  according to the present example embodiment. The processing illustrated in  FIG. 14  is performed asynchronously with the processing of updating stock information illustrated in  FIG. 13 . 
     As described in  FIG. 14 , the positioning unit  230  measures a current position (Step S 141 ). The positioning unit  230  provides current position information being the measurement result to the transmission unit  220 . Then, the transmission unit  220  transmits the current position information to the stock management device  100  (Step S 142 ). 
     The above concludes the transmission processing of current position information by an on-board device  200 . 
     Next, sales processing of an item by online shopping in the item sales system  2  will be described with reference to  FIG. 15 .  FIG. 15  is a flowchart illustrating an example of a flow of the sales processing of an item by online shopping in the item sales system  2  according to the present example embodiment. The processing illustrated in  FIG. 15  is performed asynchronously with the processing of updating stock information illustrated in  FIG. 13  and the transmission processing of current position information illustrated in  FIG. 14 . 
     In  FIG. 15 , processing by a customer terminal  300  is described on the left, processing by the stock management device  100  at the center, and processing by an on-board device  200  on the right; and a broken arrow between the respective processing steps represents a flow of primary information. An information flow is not limited to a direction of an arrow, and for example, an ACK may be transmitted in a direction reverse to the arrow. 
     A user (customer) using a customer terminal  300  inputs an instruction to start online shopping into the customer terminal  300 , and the acceptance unit  340  accepts a content of the instruction. For example, when an instruction to activate a browser is input in order to do online shopping, the control unit  320  activates the browser (Step S 151 ). For example, when processing accepted by the acceptance unit  340  is an instruction to activate an application for doing online shopping, the control unit  320  activates the application installed on the customer terminal  300 . 
     Then, the transmission unit  350  transmits information required for doing online shopping to the stock management device  100 . For example, the transmission unit  350  transmits to the stock management device  100  login information, such as a customer ID and authentication information for logging into an online shop (Step S 152 ). The login information may be input by a customer for each shopping. 
     When receiving the login information transmitted from the customer terminal  300  (Step S 153 ), the second reception unit  130  in the stock management device  100  transmits the login information to the management unit  110 . Then, the management unit  110  refers to the customer information storage unit  170  and performs user authentication (Step S 154 ). The user authentication may use any method, and therefore description is omitted in the present example embodiment. 
     Subsequently, when the customer is authenticated, the management unit  110  acquires stock information stored in the stock information storage unit  160  and provides the acquired stock information to the second transmission unit  150 . The second transmission unit  150  transmits the stock information provided from the management unit  110  to the customer terminal  300  transmitting the login information to the stock management device  100  (Step S 155 ). A timing of transmission of the stock information by the second transmission unit  150  may be after the stock management device  100  receives a transmission instruction of the stock information from the customer terminal subsequently to performing the user authentication. The timing of transmission of the stock information by the second transmission unit  150  has only to be after detection of the customer starting shopping on an online shop by use of the customer terminal  300  (performing an operation for purchasing an item by use of the customer terminal  300 ) such as after the stock management device  100  receives the aforementioned transmission instruction of the stock information. Further, the item sales system  2  may be configured not to perform user authentication. 
     The reception unit  310  in the customer terminal  300  receives the stock information from the stock management device  100  (Step S 156 ). Subsequently, the control unit  320  causes the display unit  330  to display a screen based on the received stock information (Step S 157 ). Subsequently, by use of the screen displayed based on the stock information, the customer orders an item. For example, when the customer depresses an “ADD TO CART” button illustrated in  FIG. 12 , the customer terminal  300  receives an order of an item by the customer, by the acceptance unit  340  accepting the depression of the button (Step S 158 ). Subsequently, when an instruction to end the shopping (an instruction to make payment) is input by the customer, the acceptance unit  340  accepts the instruction to end the shopping (YES in Step S 159 ). The acceptance unit  340  repeats Steps S 158  and S 159  until accepting an instruction to end the shopping. Then, the transmission unit  350  transmits order information to the stock management device  100  (Step S 160 ). 
     The second reception unit  130  in the stock management device  100  receives the order information from the customer terminal  300  (Step S 161 ). Then, the first transmission unit  140  transmits the order information to an on-board device  200  loaded on a mobile sales vehicle holding the item included in the order information (Step S 162 ). Then, the on-board device  200  receives the order information (Step S 163 ). 
     Processing in and after Step S 164  will be described with reference to  FIG. 16 . In  FIG. 16 , processing by the stock management device  100  is described at the center, processing by the on-board device  200  described on the right in  FIG. 15  is described on the right. Further, in  FIG. 16 , processing by an on-board device  200  on another mobile sales vehicle different from the mobile sales vehicle loaded with the on-board device  200  (referred to as another on-board device) indicated on the right in  FIG. 15  is described on the left. Further, a broken arrow between the respective processing steps represents a flow of primary information. An information flow is not limited to a direction of an arrow, and for example, an ACK may be transmitted in a direction reverse to the arrow. 
     It is assumed that the order information received by the stock management device  100  in Step S 161  includes an order of one “APPLE.” Then, it is assumed that the mobile sales vehicle loaded with the on-board device  200  receiving the order information in Step S 163  is the mobile sales vehicle SC. 
     When the mobile sales vehicle SC completes delivery of the item included in the order information (YES in Step S 164 ), the transmission unit  220  ends the processing on the order information by transmitting a delivery completion notification to the stock management device  100  (Step S 165 ) and then proceeds to perform delivery or sell items at its storefront. When delivery of the item included in the order information is not completed (NO in Step S 164 ), the on-board device  200  advances the processing to Step S 172 . As described above, the transmission processing of sales information illustrated in  FIG. 13  is performed asynchronously with the processing in  FIGS. 15 and 16 , and therefore, in case where the mobile sales vehicle SC sells items at its storefront before execution of Step S 172 , the processing illustrated in  FIG. 13  is performed. 
     The first reception unit  120  in the stock management device  100  confirms whether or not the delivery completion notification is received from the on-board device  200  (Step S 166 ). When the delivery completion notification is received (YES in Step S 166 ), the detection unit  180  determines that the mobile sales vehicle SC to which the order information has been transmitted has delivered the item included in the order information to the delivery address, and advances the processing to Step S 176 . The method of confirming, by the detection unit  180 , whether or not the mobile sales vehicle to which the order information has been transmitted has delivered the item included in the order information to the delivery address is not limited to the above. Further, confirmation of whether or not the item has been delivered to the delivery address may be performed by another component (for example, the first reception unit  120 ) instead of the detection unit  180 . 
     When the delivery completion notification is not received (NO in Step S 166 ), the detection unit  180  detects a presence or absence of an item becoming out-of-stock at the storefront of the mobile sales vehicle SC, out of one or more items included in the order information (Step S 167 ). Then, when an absence of an item becoming out-of-stock out of the items included in the order information is detected, that is, when an out-of-stock condition of one or more items included in the order information is not detected (NO in Step S 167 ), the stock management device  100  returns the processing to Step S 166 . When a presence of an item becoming out-of-stock out of the items included in the order information is detected, that is, when an out-of-stock condition of one or more items included in the order information is detected (YES in Step S 167 ), the specification unit  190  specifies another mobile sales vehicle arriving earliest at the delivery address, based on current positions of mobile sales vehicles indicated by current position information and a position of the delivery address indicated by delivery address information (Step S 168 ). The mobile sales vehicle to be specified is a mobile sales vehicle holding the items included in the order information. It is assumed here that the specification unit  190  specifies the mobile sales vehicle SB. 
     Then, the first transmission unit  140  transmits the order information to the on-board device  200  on the mobile sales vehicle SB (Step S 169 ). Consequently, the reception unit  240  in the on-board device  200 B on the mobile sales vehicle SB receives the order information (Step S 170 ). 
     The first transmission unit  140  also transmits a cancellation instruction to the on-board device  200 C on the mobile sales vehicle SC (Step S 171 ). Steps S 169  and S 171  may be performed at a time or may be performed in reverse order. 
     When the cancellation instruction is not received by the reception unit  240  in the on-board device  200 C on the mobile sales vehicle SC (NO in Step S 172 ), the on-board device  200  returns the processing to Step S 164 . When the cancellation instruction is received (YES in Step S 172 ), the reception unit  240  cancels the order information received in Step S 163  (Step S 173 ). 
     When the item (one apple) included in the order information becomes sold out at the storefront of the mobile sales vehicle SB before the mobile sales vehicle SB delivers the item (apple) to the delivery address, the detection unit  180  detects the sellout, the order information is transmitted to another mobile sales vehicle (for example, the mobile sales vehicle SA), and a cancellation instruction is transmitted to the mobile sales vehicle SB. 
     The following description assumes that the mobile sales vehicle SB has delivered the item included in the order information to the delivery address. 
     When the transmission unit  220  in the on-board device  200 B on the mobile sales vehicle SB transmits a delivery completion notification to the stock management device  100  (Step S 174 ), the first reception unit  120  in the stock management device  100  receives the delivery completion notification (Step S 175 ). 
     Then, the management unit  110  updates the stock information, based on the order information (Step S 176 ). As described above, the item (one apple) included in the order information has been delivered to the delivery address by the mobile sales vehicle SB, and therefore the management unit  110  decreases the stock quantity of “APPLE” in the stock information illustrated in  FIG. 8  by one, the stock information being about stock of items held by the mobile sales vehicle SB. 
     The above concludes the sales processing of items by online shopping by the item sales system  2 . 
     As described above, in the item sales system  2 , the management unit  110  in the stock management device  100  updates stock information, based on sales information received by the first reception unit  120  and order information received by the second reception unit  130 . Further, the first transmission unit  140  transmits order information to an on-board device  200  on a mobile sales vehicle holding an ordered item included in the order information. Then, when an item included in the order information becomes out-of-stock by the item being sold at the storefront of the mobile sales vehicle to which the order information has been transmitted, the detection unit  180  detects the item becoming out-of-stock. Then, the first transmission unit  140  transmits the order information to an on-board device  200  on a mobile sales vehicle holding the item included in the order information, the mobile sales vehicle being different from the mobile sales vehicle loaded with the on-board device  200  to which the order information has been transmitted. Consequently, the mobile sales vehicle loaded with the on-board device  200  can deliver the ordered item to a customer ordering the item. 
     Accordingly, the item sales system  2  including the stock management device  100  according to the present example embodiment can deliver, to a customer doing online shopping, an item which the customer wants, even when the item is purchased at a mobile sales vehicle. 
     About Hardware Configuration 
     Each component in each of the stock management device, the on-board device, and the customer terminal, according to the respective example embodiments of the present disclosure, represents a functional unit block. For example, each component in each of the stock management device, the on-board device, and the customer terminal is implemented in part or in whole with any combination of an information processing device  900  as illustrated in  FIG. 17  and a program.  FIG. 17  is a block diagram illustrating a hardware configuration example of the information processing device  900  implementing each component in each of the stock management device, the on-board device, and the customer terminal. As an example, the information processing device  900  includes a configuration as described below.
         A central processing unit (CPU)  901     A read only memory (ROM)  902     A random access memory (RAM)  903     A program  904  loaded into the RAM  903     A storage device  905  storing the program  904     A drive device  907  performing reading from and writing to a recording medium  906     A communication interface  908  connected to a communication network  909     An input-output interface  910  performing input and output of data   A bus  911  connecting the respective components       

     Each component in each of the stock management device, the on-board device, and the customer terminal, according to the respective example embodiments, is implemented by the CPU  901  acquiring and executing the program  904  implementing a function of the component. For example, the program  904  implementing the function of each component in each of the stock management device, the on-board device, and the customer terminal is pre-stored in the storage device  905  or the ROM  902 , and is read by the CPU  901  as needed. The program  904  may be provided to the CPU  901  through the communication network  909 ; or the program may be pre-stored in the recording medium  906 , and the drive device  907  may read the program and provide the program to the CPU  901 . 
     There are various modified examples of the implementation method of each of the stock management device, the on-board device, and the customer terminal. For example, each of the stock management device, the on-board device, and the customer terminal may be implemented with any combination of a separate information processing device  900  and a program, for each component. Further, a plurality of components included in each of the stock management device, the on-board device, and the customer terminal may be implemented with any combination of a single information processing device  900  and a program. 
     Further, each component in each of the stock management device, the on-board device, and the customer terminal is implemented in part or in whole with another general-purpose or dedicated circuit, a processor, or the like, or a combination thereof. The above may be configured with a single chip or may be configured with a plurality of chips connected through a bus. 
     Each component in each of the stock management device, the on-board device, and the customer terminal may be implemented in part or in whole with a combination of the aforementioned circuit or the like, and a program. 
     When each component in each of the stock management device, the on-board device, and the customer terminal is implemented in part or in whole with a plurality of information processing devices, circuits, or the like, the plurality of information processing devices, circuits, or the like may be arranged in a concentrated manner or be arranged in a distributed manner. For example, the information processing devices, the circuits, or the like may be implemented in a form of being connected to one another through a communication network, such as a client-server system, a cloud computing system, or the like. 
     The respective aforementioned example embodiments are preferred example embodiments of the present disclosure, and the scope of the present disclosure is not limited to the respective aforementioned example embodiments; and a person skilled in the art can make example embodiments which include various changes through modifying and substituting the respective aforementioned example embodiments without departing from the spirit and scope of the present disclosure. 
     The aforementioned example embodiments may also be described in whole or in part as the following supplementary notes but are not limited thereto. 
     (Supplementary Note 1) 
     A stock management device comprising: 
     management means for managing stock information about stock of an item held by each of a plurality of mobile sales vehicles; 
     first reception means for receiving, from each of the plurality of mobile sales vehicles, sales information indicating an item sold at a storefront of the mobile sales vehicle; 
     second reception means for receiving, from a customer terminal, order information including information about an item ordered based on the stock information transmitted to the customer terminal; 
     transmission means for transmitting the order information to the mobile sales vehicle holding the ordered item included in the order information; and 
     detection means for detecting the item included in the order information becoming out-of-stock at the storefront of the mobile sales vehicle to which the order information has been transmitted, before the item is delivered to a delivery address, wherein, 
     when the item becoming out-of-stock is detected by the detection means, the transmission means transmits the order information to another mobile sales vehicle holding the ordered item included in the order information and being different from the mobile sales vehicle to which the order information has been transmitted, and 
     the management means updates the stock information based on at least one of the sales information and the order information. 
     (Supplementary Note 2) 
     The stock management device according to Supplementary note 1, wherein 
     the transmission means transmits an instruction to cancel the order information to a mobile sales vehicle to which the order information has been transmitted. 
     (Supplementary Note 3) 
     The stock management device according to Supplementary note 1 or 2, wherein 
     the detection means detects the item becoming out-of-stock based on the sales information. 
     (Supplementary Note 4) 
     The stock management device according to any one of Supplementary notes 1 to 3, wherein 
     the order information includes delivery address information indicating a delivery address of the item, 
     the first reception means further receives current position information indicating current positions of the plurality of mobile sales vehicles, 
     the stock management device further comprises: specification means for specifying a mobile sales vehicle arriving earliest at the delivery address out of one or more of the other mobile sales vehicles holding the ordered item, based on current positions of the mobile sales vehicles indicated by the current position information, and a position of the delivery address indicated by the delivery address information, and 
     the transmission means transmits the order information to the specified mobile sales vehicle. 
     (Supplementary Note 5) 
     An item sales system comprising: 
     a stock management device; 
     an on-board device being loaded on each of a plurality of mobile sales vehicles and transmitting, to the stock management device, sales information indicating an item sold at a storefront of each of the plurality of mobile sales vehicles; and 
     one or more customer terminals, wherein 
     the stock management device includes:
         management means for managing stock information about stock of an item held by each of the plurality of mobile sales vehicles;   first reception means for receiving the sales information from each of the plurality of mobile sales vehicles;   second reception means for receiving, from the customer terminal, order information including information about an item ordered based on the stock information transmitted to the customer terminal;   transmission means for transmitting the order information to the mobile sales vehicle holding the ordered item included in the order information; and   detection means for detecting the item included in the order information becoming out-of-stock at a storefront of the mobile sales vehicle to which the order information has been transmitted, before the item is delivered to a delivery address, wherein,       

     when the item becoming out-of-stock is detected by the detection means, the transmission means transmits the order information to another mobile sales vehicle holding the ordered item included in the order information and being different from a mobile sales vehicle to which the order information has been transmitted, and 
     the management means updates the stock information, based on at least one of the sales information and the order information. 
     (Supplementary Note 6) 
     The item sales system according to Supplementary note 5, wherein 
     the transmission means transmits an instruction to cancel the order information to a mobile sales vehicle to which the order information has been transmitted. 
     (Supplementary Note 7) 
     The item sales system according to Supplementary note 5 or 6, wherein 
     the detection means detects the item becoming out-of-stock based on the sales information. 
     (Supplementary Note 8) 
     The item sales system according to any one of Supplementary notes 5 to 7, wherein 
     the order information includes delivery address information indicating a delivery address of the item, 
     the first reception means further receives current position information indicating current positions of the plurality of mobile sales vehicles, 
     the stock management device further comprises: specification means for specifying a mobile sales vehicle arriving earliest at the delivery address out of one or more of the other mobile sales vehicles holding the ordered item, based on current positions of the mobile sales vehicles indicated by the current position information, and a position of the delivery address indicated by the delivery address information, and 
     the transmission means transmits the order information to the specified mobile sales vehicle. 
     (Supplementary Note 9) 
     A stock management method comprising: 
     managing stock information about stock of an item held by each of a plurality of mobile sales vehicles; 
     receiving, from each of the plurality of mobile sales vehicles, sales information indicating an item sold at a storefront of the mobile sales vehicle; 
     receiving, from a customer terminal, order information including information about an item ordered based on the stock information transmitted to the customer terminal; 
     transmitting the order information to the mobile sales vehicle holding the ordered item included in the order information; and 
     detecting the item included in the order information becoming out-of-stock at the storefront of the mobile sales vehicle to which the order information has been transmitted, before the item is delivered to a delivery address, wherein, 
     when the item becoming out-of-stock is detected, transmitting the order information to another mobile sales vehicle holding the ordered item included in the order information and being different from the mobile sales vehicle to which the order information has been transmitted, and 
     updating the stock information based on at least one of the sales information and the order information. 
     (Supplementary Note 10) 
     The stock management method according to Supplementary note 9, further comprising: 
     transmitting an instruction to cancel the order information to a mobile sales vehicle to which the order information has been transmitted. 
     (Supplementary Note 11) 
     A stock management method in an item sales system including a stock management device, an on-board device loaded on each of a plurality of mobile sales vehicles, and one or more customer terminals, the stock management method comprising: 
     managing, by the stock management device, stock information about stock of an item held by each of the plurality of mobile sales vehicles; 
     transmitting, by the on-board device, to the stock management device, sales information indicating an item sold at a storefront of a mobile sales vehicle loaded with the on-board device; 
     transmitting, by the customer terminal, to the stock management device, order information including information about an item ordered based on the stock information received from the stock management device; 
     receiving, by the stock management device, the sales information from the on-board device; 
     receiving, by the stock management device, the order information from the customer terminal; 
     transmitting, by the stock management device, the order information to the mobile sales vehicle holding the ordered item included in the order information; and 
     detecting, by the stock management device, the item included in the order information becoming out-of-stock at the storefront of the mobile sales vehicle to which the order information has been transmitted, before the item is delivered to a delivery address, wherein, 
     when the item becoming out-of-stock is detected, transmitting, by the stock management device, the order information to another mobile sales vehicle holding the ordered item included in the order information and being different from the mobile sales vehicle to which the order information has been transmitted, and 
     updating, by the stock management device, the stock information based on at least one of the sales information and the order information. 
     (Supplementary Note 12) 
     The stock management method according to Supplementary note 11, further comprising: 
     transmitting, by the stock management device, an instruction to cancel the order information to a mobile sales vehicle to which the order information has been transmitted. 
     (Supplementary Note 13) 
     A non-transitory computer readable storage medium storing a program that causes a computer to execute: 
     a process of managing stock information about stock of an item held by each of a plurality of mobile sales vehicles; 
     a process of receiving, from each of the plurality of mobile sales vehicles, sales information indicating an item sold at a storefront of the mobile sales vehicle; 
     a process of receiving, from a customer terminal, order information including information about an item ordered based on the stock information transmitted to the customer terminal; 
     a process of transmitting the order information to the mobile sales vehicle holding the ordered item included in the order information; and 
     a process of detecting the item included in the order information becoming out-of-stock at the storefront of the mobile sales vehicle to which the order information has been transmitted, before the item is delivered to a delivery address, wherein, 
     when the item becoming out-of-stock is detected by the detection means, a process of transmitting the order information to another mobile sales vehicle holding the ordered item included in the order information and being different from the mobile sales vehicle to which the order information has been transmitted, and 
     a process of updating the stock information based on at least one of the sales information and the order information. 
     (Supplementary Note 14) 
     The storage medium according to Supplementary note 13, wherein, the program that causes a computer to execute: 
     a process of transmitting an instruction to cancel the order information to a mobile sales vehicle to which the order information has been transmitted. 
     This application claims priority based on Japanese Patent Application No. 2016-162595 filed on Aug. 23, 2016, the disclosure of which is hereby incorporated by reference thereto in its entirety. 
     REFERENCE SIGNS LIST 
     
         
           1  Item sales system 
           2  Item sales system 
           10  Stock management device 
           11  Management unit 
           12  First reception unit 
           13  Second reception unit 
           14  Transmission unit 
           15  Detection unit 
           20  On-board device 
           30  Customer terminal 
           100  Stock management device 
           110  Management unit 
           120  First reception unit 
           130  Second reception unit 
           140  First transmission unit 
           150  Second transmission unit 
           160  Stock information storage unit 
           170  Customer information storage unit 
           180  Detection unit 
           190  Specification unit 
           200  On-board device 
           210  Sales information acceptance unit 
           220  Transmission unit 
           230  Positioning unit 
           240  Reception unit 
           300  Customer terminal 
           310  Reception unit 
           320  Control unit 
           330  Display unit 
           340  Acceptance unit 
           350  Transmission unit