Abstract:
A history concerning circumstances surrounding each item during distribution is obtained from a reusable measuring apparatus attached to the item or measuring apparatuses placed in locations such as rooms. Information about items of products in a distribution channel are managed by associating position information indicating the locations at both ends of a place where circumstance information is measured with measuring apparatuses with the information indicating the measuring apparatuses. When items are moved during distribution, information contained in a tag attached to the items is read at the locations at both ends of the place and is managed. To obtain information about circumstances surrounding an item at a particular place in the distribution channel, values measured with the measuring apparatuses during a relevant period are obtained on the basis of the position information indicating the locations at both ends of the particular place and on the read dates and times.

Description:
CLAIM OF PRIORITY  
       [0001]     The present application claims priority from Japanese application 2005-159839 filed on May 31, 2005, the content of which is hereby incorporated by reference into this application.  
       FIELD OF THE INVENTION  
       [0002]     The present invention relates to a circumstance information management system and method for storing and searching information about circumstances surrounding products such as temperature and humidity in product manufacturing, distribution, and stages.  
       BACKGROUND OF THE INVENTION  
       [0003]     Circumstance information such as temperature and humidity is measured today with apparatuses such as temperature sensors and humidity sensors provided in places such as warehouses or factories or on truck beds. If an abnormality is found in circumstances such as temperature or humidity, products are inspected and/or discarded or some other actions are taken at the location where the abnormality has occurred.  
         [0004]     Japanese Patent Laid-Open No. 2004-315154 describes a method in which a data carrier including an ID tag containing ID information and means for measuring and transmitting circumstance information such as temperature and humidity is attached to products, the circumstance information such as temperature and humidity measured and stored in the data carrier is transmitted to a data server in each of distribution stages such as packaging, cargo handling, transport, and storage stages, the circumstance information concerning each product item in the distribution is managed on the data server, and filtering is performed on the data server for detecting circumstance data such as temperature that does not satisfies a quality assurance standard, thereby finding defective products.  
         [0005]     There is a growing demand for tracking down the range of defective products or ex-post investigation of cause of defects by keeping track of circumstance information concerning each item of products, such as temperature and humidity, as in the technique described in Japanese Patent Laid-Open No. 2004-315154. However, the method described in Japanese Patent Laid-Open No. 2004-315154 requires the attachment of an expensive data carrier to each item and therefore it is difficult to introduce the method in many cases due to the costs.  
         [0006]     The costs may be reduced by reusing expensive data carriers. However, the method described in Japanese Patent Laid-Open No. 2004-315154 does not allow data carriers to be reused because the method manages items and data carries by associating them in a one-to-one relationship and, if the data carriers were reused, it would be impossible to determine which item is associated with circumstance information such as temperature or humidity obtained with a data carrier.  
         [0007]     An object of the present invention is to provide a method or system capable of obtaining and managing circumstance histories such as a temperature or humidity history of each item by using circumstance information obtaining apparatuses such as temperature sensors or humidity sensors placed in particular locations such as warehouses, factories, and truck beds.  
         [0008]     Another object of the present invention is to provide a method or system capable of obtaining and managing circumstance histories for each item in a form that allows circumstance information obtaining apparatuses to be reused even if they are attached to items or containers that moves along with items.  
       SUMMARY OF THE INVENTION  
       [0009]     To solve the problem, a circumstance information management system according to the present invention uses the following two aspects.  
         [0010]     In a first aspect, information about circumstances surrounding each item in particular locations is obtained from information such as temperature or humidity measured from time to time with circumstance information obtaining apparatuses such as temperature sensors or humidity sensors installed in fixed locations such as a warehouse, factory, and truck beds (a circumstance history) and from information obtained with movement information obtaining apparatuses that detect the movement of each item (a movement history). In particular, movement information obtaining apparatuses are placed at the entrance to and exit from a place such as a warehouse where the circumstance history is to be obtained with circumstance information obtaining apparatuses and the relationships between the place and the circumstance information obtaining apparatuses are managed as circumstance-movement association master. Recorded in the circumstance history are identifications of the circumstance information obtaining apparatuses, circumstance information measurement dates and time, and measured values of circumstance information. Recorded in the movement history are passage locations, passage dates and times and identifications of items such as item IDs. To obtain a circumstance history of a particular item in a particular place, the dates and times at which the item ID associated with the item entered and left the place are obtained from the movement history and values measured with the circumstance information obtaining apparatuses during the period between the passage dates and times are obtained.  
         [0011]     Furthermore, monitor conditions such as the upper and lower limits of measured values are set for each individual item or each type of item and an item that meets a monitor condition is retrieved from the circumstance history and the movement history as follows. First, the circumstance history is searched for a measured value by using the monitor condition. If there is a measured value that meets the monitor condition, the relevant circumstance information obtaining apparatus and the measurement date and time are obtained from the circumstance history. Then, the place associated with the circumstance information obtaining apparatus is retrieved from a circumstance-movement association master and determination is made from the movement history as to whether there is a history record that indicates that the item to which the monitor condition is applied passed through the place at the measurement date and time. If the item stays in the place, notification is provided that there is an item that meets the monitor condition.  
         [0012]     In a second aspect, a circumstance information obtaining apparatus is attached to each individual item or an object such as a container that moves along with an item and a circumstance history for each item is traced. The circumstance information obtaining apparatus is reusable.  
         [0013]     In particular, identification information such as an item ID of an item, a circumstance information obtaining apparatus attached to the item, the attachment date and time, and the removal date and time are managed using a circumstance-item association master. To obtain a circumstance history of a particular item, the identification of the circumstance information obtaining apparatus attached to the item, the attachment date and time, the removal date and time are obtained from a circumstance-item association master, and a measured value associated with the circumstance information obtaining apparatus and measured during the period between the attachment date and time and the removal date and time is obtained from the circumstance history.  
         [0014]     According to the first aspect of the present invention, values measured with circumstance information obtaining apparatuses such as temperature sensors or humidity sensors that are placed in particular places such as a warehouse, a factory, or truck beds are used to obtain a circumstance history such as a temperature history or a humidity history of each item. Therefore only a small number of circumstance information obtaining apparatuses have to be provided and an apparatus does not have to be attached to each item. Accordingly, information about circumstances surrounding items can be managed at low costs. According to the second aspect of the present invention, a circumstance history of each item can be obtained even if a circumstance information obtaining apparatus attached to each item or a container that moves along with each item is reused. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0015]      FIG. 1  shows an overall configuration of the circumstance information management system according to an embodiment of the present invention;  
         [0016]      FIG. 2  shows an example in which the circumstance information management system according to an embodiment of the present invention is applied to products distribution operations;  
         [0017]      FIG. 3  shows a circumstance-movement association master according to an embodiment of the present invention;  
         [0018]      FIG. 4  shows a circumstance-item association master according to an embodiment of the present invention;  
         [0019]      FIG. 5  shows a circumstance monitor condition master according to an embodiment of the present invention;  
         [0020]      FIG. 6  shows an item type master according to an embodiment of the present invention;  
         [0021]      FIG. 7  shows a circumstance history according to an embodiment of the present invention;  
         [0022]      FIG. 8  shows a movement history according to an embodiment of the present invention;  
         [0023]      FIG. 9  shows a process flow of a circumstance monitoring program according to an embodiment of the present invention;  
         [0024]      FIG. 10  shows an exemplary circumstance abnormality warning screen according to an embodiment of the present invention;  
         [0025]      FIG. 11  shows an exemplary search screen according to an embodiment of the present invention;  
         [0026]      FIG. 12  shows an exemplary search result screen according to an embodiment of the present invention;  
         [0027]      FIG. 13  shows a process flow of a circumstance history search program according to an embodiment of the present invention;  
         [0028]      FIG. 14  shows an example in which the circumstance information management system according to the present invention is applied to products distribution operations;  
         [0029]      FIG. 15  shows a process flow of a circumstance monitoring program according to an embodiment of the present invention;  
         [0030]      FIG. 16  shows an exemplary circumstance abnormality warning screen according to an embodiment of the present invention;  
         [0031]      FIG. 17  shows an exemplary search screen according to an embodiment of the present invention;  
         [0032]      FIG. 18  shows an exemplary search result screen according to an embodiment of the present invention;  
         [0033]      FIG. 19  shows a process flow of a circumstance history search program according to an embodiment of the present invention; and  
         [0034]      FIG. 20  shows an overall configuration of a circumstance information management system according to an embodiment of the present invention. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0035]     A first embodiment of the present invention will be described with reference to the accompanying drawings.  
       First Embodiment  
       [0036]      FIG. 1  shows a system configuration of a circumstance information management system according to a first embodiment of the present invention.  
         [0037]     Movement information input apparatuses  11  are devices such as an electronic tag reader, a barcode reader, and a keyboard for generating movement information  14  based on the movement of products and inputting it in the circumstance information management system  10 . An input unit  21  receives movement information  14  and stores it in a movement history  28 .  
         [0038]     The movement information  14  is information concerning the shipment and arrival of products, storage of products in and shipping from a warehouse, and movement of products within a factory or warehouse. The movement information  14  includes item IDs, which are identifiers of products, dates and times on which products moved, such as shipping dates and times, arrival dates and times, dates and times at which products were stored in or shipped from a warehouse, location IDs which indicate locations from or to which products have been moved or through which products have passed, and information indicating the state of movement such as “arrival” or “shipping”.  
         [0039]     Circumstance information input apparatuses  12  are devices such as a temperature sensor or a keyboard for measuring circumstance data such as temperature, humidity, pressure, pH, acceleration, odor, or the concentration of a particular substance such as carbon dioxide or carbon monoxide, generating circumstance information  15  from the data, and imputing it in the circumstance information management system  10 . The input unit  21  receives the circumstance information  15  and stores it in a circumstance history  27 .  
         [0040]     Circumstance information  15  includes measured values concerning circumstances such as temperature, the measurement dates and times, and information about measuring apparatuses.  
         [0041]     A circumstance-movement association master  23  defines locations in which circumstance information measuring apparatuses measure circumstance data. In particular, each location where circumstance data is measured is defined with a location ID indicating movement into the location, the state of the movement, and a location ID indicating movement from the location and the state of the movement. If just location IDs are enough for identifying the history of movement to and from locations, the states of movements are unnecessary.  
         [0042]     A circumstance history search program  22  generates a circumstance history  16  of each item of products, which indicates a history of circumstances associated with a particular item ID from a movement history  28 , circumstance history  27 , and the circumstance-movement association master  23  and outputs it to an output apparatus  13  such as a printer or a display.  
         [0043]     A circumstance monitor condition master  25  monitors the circumstance information  15  or the circumstance history  27  and defines conditions for detecting abnormalities in circumstances surrounding each item of products or each type of products defined in an item type master  26 , which will be described later. The conditions to be monitored may include those defining upper and lower limits of a circumstance value and the amount of a variation in a circumstance value per unit time.  
         [0044]     The item type master  26  defines the types of product classified by product name or article code, or the types of product classified by storage condition such as “chilled food” or “frozen food”. The type is defined with a combination of an item type and an item ID of an item that belongs to the item type.  
         [0045]     A circumstance monitoring program  29  monitors the circumstance history  27  or circumstance information  15  in accordance with circumstance monitor conditions for the circumstance history for each item type defined in the circumstance monitor condition master  25 , identifies an item of products that meets a condition from the item type master  26  which defines which item belongs to which item type and from the movement history  28 , and outputs a warning  17  including information such as the circumstance monitor condition, the item that meets the circumstance monitor condition, the location, and the date and time to an output apparatus  13 . Processes performed by the circumstance history search program  22  and circumstance monitoring program  29 , which will be described later, may be stored in a medium that can be read by computer such as personal computers and may be read from the medium and executed as needed.  
         [0046]     Referring to  FIG. 2 , processes in the circumstance information management system according to the first embodiment will be described with respect to an example in which the processes are applied to products distribution operations in which products are stored in a warehouse through a products receipt location and are shipped from the warehouse through a shipping preparation location after a certain period of time.  
         [0047]     While the embodiment will be described with respect to temperature, any other data such as humidity, pressure, pH, acceleration, or odor may be used. It may be the concentration of a particular substance such as carbon dioxide or carbon monoxide. In such a case, the circumstance information input apparatuses may be humidity sensors, pressure sensors, pH sensors, acceleration sensors, odor sensors, gas concentration sensors, or the like.  
         [0048]     It is assumed that items of products  43 , each equipped with a tag  51  containing an item ID  30  of the item  43 , are moving. The tag  51  may be a machine-readable tag such as an electronic tag or a barcode, or may be a paper tag containing an item ID  30  visible to the human eye.  
         [0049]     When an item  43  arrives at the warehousing location that is the entrance to a warehouse  41 , an item ID  30  of the item  43  is read by a reader  52 , which is equivalent to a movement information input apparatus  11  in  FIG. 1 , and is then stored in the warehouse  41 . The reader  52  reads the item ID recorded on the tag  51  and inputs or sends it to the circumstance information management system  10 . Depending on the type of the tag  51 , a human operator, instead of an electric tag reader or barcode reader, may read the item ID written on the tag  51  and input it through a keyboard.  
         [0050]     The reader  52  inputs, into the circumstance information management system  10 , storage information  31 , which is equivalent to the movement information  14  in  FIG. 1 , including the item ID  30 , the read date and time as the movement date and time, a reader ID of the reader  52  as the movement location ID, and “Storage” as the movement state.  
         [0051]     When receiving the storage information  31 , the circumstance information management system  10  stores it in a movement history  28 .  
         [0052]      FIG. 8  shows an example of the movement history  28 . For example, the record denoted by reference numeral L 84  indicates that on storage of an item with the item ID “301” in the warehouse  41 , a reader with the reader ID “200” read and stored the reader ID at the date and time “00:30 Jan. 3, 2005”.  
         [0053]     The temperature in the warehouse  41  is measured with a temperature sensor  53 , which is equivalent to a circumstance information input apparatus  12  in  FIG. 1 , at regular time intervals regardless of the storage and shipment of items  43 . The measurement may be conducted every one second or every one hour. If the temperature measured with the temperature sensor at “01:00 Jan. 3, 2005” is “−22° C.”, the temperature sensor  53  sends the measured temperature “−22° C.”, the measurement date and time “01:00 Jan. 3, 2005”, and the temperature sensor ID of the measuring apparatus to the circumstance information management system  10  as temperature information  32 , which is equivalent to the circumstance information  15  in  FIG. 1 .  
         [0054]     When receiving the temperature information  32 , the circumstance information management system  10  stores it in a circumstance history  27 .  
         [0055]      FIG. 7  shows an example of the circumstance history  27 . Record L 73  in  FIG. 7  represents temperature information  32  obtained with a sensor ID “100” in the example described.  
         [0056]     When an item  43  is taken out of the warehouse  41  and moved to the shipping preparation location  42 , a reader  54  reads the item ID  33  and inputs it into the circumstance information management system  10  together with the reading date and time, the ID of the reader  54  which is the movement location ID, and the state of movement “Shipment”, as warehouse shipping information  34 , in a manner similar to the storage to the warehouse described above.  
         [0057]     The record denoted by L 85  in  FIG. 8  indicates that on shipment of an item with the item number ID “301” from the warehouse, a reader with the reader ID “201” has read and stored the item ID at “04:30 Jan. 3, 2005”, as with the example of storage to the warehouse.  
         [0058]     In this way, information is recorded in the movement history  28  which is a record concerning the movement of products and the circumstance history  27  which is a circumstance measurement history.  
         [0059]     The circumstance-movement association master  23 , circumstance monitor condition master  25 , and item type master  26  in the first embodiment will be described below.  
         [0060]      FIG. 3  shows an example of the circumstance-movement association master  23 . Data denoted by reference numeral L 31  defines that the circumstances surrounding an item with the movement location ID “200” and the movement state “Storage in the warehouse” and an item with the movement location ID “201” and the movement state “Shipment from the warehouse” are measured with a circumstance information measuring apparatus with the measuring apparatus ID “100” during their movement. Data denoted by reference numeral L 32  defines that the circumstances surrounding an item with the movement location ID “202” and the movement state “Storage in the warehouse” and an item with the movement location ID “202” and the movement state “Shipment from the warehouse” are measured with a circumstance information measuring apparatus with the measuring apparatus ID “101”.  
         [0061]      FIG. 5  shows an example of the circumstance condition master  26 . Data denoted by reference numeral L 51  defines that a condition should be detected in which a measured value in the circumstance information about or the circumstance history of an item with the item type ID “40” is out of the range between an upper-limit temperature of “−18° C.” and a lower-limit temperature of “−25° C.”. Data denoted by reference numeral L 52  defines that a condition should be detected in which a measured value in the circumstance information about or the circumstance history of an item with the item type ID “41” is out of the range between a upper-limit temperature of “−15° C.” and a lower-limit temperature of “−25° C.”.  
         [0062]      FIG. 6  shows an example of the item type master  26 . Data denoted by reference numerals L 62 , L 64 , and L 65  define that items with the item IDs “301”, “302”, and “303” belong to a item type with item type ID “40” respectively. Data denoted by reference numerals L 61  and L 63  define that items with the item IDs “302” and “303” belong to a item type with the item type ID “41” respectively.  
         [0063]     A process of the environment history search program  22  will be described with reference to a process flow shown in  FIG. 13 .  
         [0064]     At step S 20  in  FIG. 13 , a movement history record of a particular item is obtained from the movement history  28  shown in  FIG. 8 . The particular item is specified by entering an item ID, “301” in an item ID entry field  304  in a search screen  303  shown in  FIG. 11 , for example, and then pressing a search button  305 . When the item ID “301” is entered as in the example shown, history records L 81 , L 84 , L 85 , and L 88  in  FIG. 8  with item ID  281  “300” are obtained as the result of the search.  
         [0065]     Then, at step S 21 , the movement history  28  is searched for time at which the item was at a place such as a warehouse  41  where a temperature sensor is installed ( FIG. 3  shows an example of the circumstance-movement association master.)  
         [0066]     In particular, the sets of the movement location IDs  280  and a movement states  283  obtained from the movement history at step S 20  are searched through for a match with a set of a movement location ID (entrance)  231  and a movement state (entrance)  232  in the circumstance-movement association master  23  shown in  FIG. 3  and a match with a set of a movement location ID (exit)  233  and a movement state (exit)  234 , and the measuring apparatus IDs and the durations during which the item was in those locations are obtained.  
         [0067]     In the example described, the set of the movement ID  280  and the movement state  283  indicated by reference numeral L 84  in  FIG. 8  matches the set of the movement location ID (entrance)  231  and the movement state (entrance)  232  indicated by reference numeral L 31  in  FIG. 3 ; the set of movement location ID  280  and the movement state  283  indicated by L 85  matches the set of the movement location ID (exit)  233  and the movement state (exit)  234  indicated by L 31 . Therefore, the period from the movement date and time  282  “00:30 Jan. 3, 2005” indicated by L 84  to the movement date and time “04:30 Jan. 3, 2005” indicated by L 85  is obtained as the duration during which the item was at the location at which the measuring apparatus with the measuring apparatus ID  230  “100” indicated by L 31  is installed.  
         [0068]     Then, steps S 22  to S 24  are repeated for each measuring apparatus ID obtained at step S 21 . Because only one measuring apparatus ID, “100”, has been obtained in the example described, steps  22  to S 24  are performed once. At step S 23 , a measured value that matches the measuring apparatus ID obtained at step S 21  and was measured during the duration is obtained from the circumstance history  27 , and the temperature history  35  for each item which consists of the measuring apparatus information (temperature sensor information in this embodiment) and is equivalent to the item-by-item circumstance history  16  in  FIG. 1  is sent to and displayed on a display  55  which is equivalent to an output apparatus  13 .  
         [0069]     In the example described, obtained from the circumstance history  27  shown  FIG. 7  are the measured values  272  in history records L 73 , L 74 , L 75 , and L 76  with the measuring apparatus ID “100” during the period from “00:30 Jan. 3, 2005” to “04:30 Jan. 3, 2005” indicated by the measurement time and date  271 .  FIG. 12  shows an item-by-item circumstance history screen  306  displayed on the display  55 .  
         [0070]     A process of the circumstance monitoring program  29  will be described with reference to the process flow in  FIG. 9 . The process may be performed when temperature information  32  is registered in the circumstance information management system  10  or may be performed later for each row of the circumstance history  27 . The process will be described here on the assumption that the measuring apparatus ID “100”, the measurement date and time “03:00 Jan. 3, 2005”, and the measured value “−16° C.” have been inputted as the temperature information  32 .  
         [0071]     First, all circumstance monitor conditions are obtained from the circumstance monitor condition master  25  at step S 00 .  
         [0072]      FIG. 5  shows an example of the circumstance condition master  25 . As shown, the circumstance condition master  25  includes an item type ID  250  indicating the type of an item and the lower-limit temperature  251  and upper-limit temperature  252  of a measured value for the item to be monitored. Steps S 01  to S 010  are repeated for each circumstance monitor condition read at step S 00 . At step S 02 , determination is made as to whether the measured value in the temperature information  32  meets a circumstance monitor condition. If it does, the process proceeds to step S 03 . It is determined here that the value meets a condition if it is less than the lower-limit temperature  251  mentioned above or exceeds the upper-limit temperature  255 . In this example, determination is made as to whether the measured value “−16° C.” meets any of the conditions denoted by reference numerals  51  and L 52 . Because the measured value “−16° C.” exceeds the upper-limit temperature “−18° C.” in the condition L 51 , it is determined that the measured value meets the circumstance monitor condition L 51 , and the process proceeds to step S 03 .  
         [0073]     At step S 03 , an item that matches the item type ID  250  in the circumstance monitor condition met is retrieved from the item type master  26 .  FIG. 6  shows an example of the item type master  26 . The item type master  26  consists of item type ID  260  indicating the types of item and item IDs  261  that belong to the types. In this example, item IDs  261  that match the item type ID “40” contained in the circumstance monitor condition L 51  are searched for, and item IDs “301”, “303”, and “304” are obtained from the data L 62 , L 64 , and L 65 .  
         [0074]     Then, steps S 04  to S 09  are repeated for each item ID obtained at step S 03  to determine from the movement history  28  and the circumstance-movement association master  23  whether the item is at a location where the temperature sensor that measured the temperature that meets the circumstance monitor condition is placed. At step S 05 , a movement location ID (entrance)  231 , movement state (entrance)  232 , a movement location ID (exit)  233 , and movement state (exit)  234  that match the measuring apparatus ID in the temperature information  32  are obtained from the circumstance-movement association master  26  shown in  FIG. 3 . In this example, the movement ID (entrance)  231  “200” and the movement state (entrance)  232  “Storage in warehouse” and the movement ID (exit)  233  “201” and the movement state (exit)  234  “Shipment from warehouse” in L 31  that correspond to the measuring ID “100” of the temperature sensor that measured the temperature are obtained.  
         [0075]     At step S 06 , determination is made from the movement history  28  shown in  FIG. 8  as to whether the item with the item ID obtained at step S 03  has passed the location indicted by the movement location ID (exit)  233  and the movement state (exit)  234  obtained at step S 05 . If not, the process proceeds to step S 07 .  
         [0076]     Here, it is also determined that the item has not passed the exit if there is not a record of passage through the exit in the movement history  28 . In this example, the movement date and time  282  “04:30 Jan. 3, 2005” in record L 85  with the item ID “301”, the movement location ID  280  “201”, and the movement state  283  “Shipment from the warehouse” is later than the temperature measurement date and time “03:00 Jan. 3, 2005”. Therefore it is determined that the item had not passed the exit at the temperature measurement time, and consequently the process proceeds to step S 07 .  
         [0077]     At step S 07 , determination is made from the movement history  28  shown in  FIG. 8  as to whether the item with the item ID obtained at step S 03  has passed the location with the movement location ID (entrance)  231  and the movement state (entrance)  232  obtained at step S 05 . If so, the process proceeds to step S 08 .  
         [0078]     In this example, the movement date and time  282  “00:30 Jan. 3, 2005” in record L 84  with the item ID “301”, the movement ID  280  “200”, and the movement state  283  “Storage in the warehouse” is earlier than the temperature measurement date and time “03:00 Jan. 3, 2005”. Therefore it is determined that the item has passed the entrance at the temperature measurement time, and consequently the process proceeds to step S 08 .  
         [0079]     At step S 08 , a warning  36 , which is equivalent to the warning  17  shown in  FIG. 1 , indicating that the item obtained through the process meets the circumstance monitoring information is sent to and displayed on the display  55 , which is equivalent to the output apparatus  13 .  FIG. 10  shows an exemplary warning screen  301 .  
         [0080]     In this example, steps S 04  to S 09  are repeated for data L 64  and L 65 . Because the movement histories of the items with the item ID  261  “303” and “304” in data L 64  and L 65  are not contained in the movement history  28  shown in  FIG. 8 , it is determined at step S 07  that the items have not passed the entrance, and the process will end. Then, steps S 01  to S 010  are repeated for the circumstance monitor condition L 52 . It is determined at step S 02  that the measured temperature “−16° C.” is not beyond the lower-limit temperature “−25° C.” and the upper-limit temperature “−15° C.” in the conditions L 52  and therefore the process will end.  
       Second Embodiment  
       [0081]     A second embodiment of the present invention will be described with respect to the accompanying drawings.  FIG. 20  shows a system configuration of a circumstance information management system according to the second embodiment.  
         [0082]     Referring to  FIG. 20 , an overall configuration of the circumstance information management system  18  will be described.  
         [0083]     The movement information input apparatuses  11 , movement information  14 , circumstance information input apparatuses, output apparatuses  13 , circumstance information  15 , item-by-item circumstance history  16 , warning  17 , input unit  21 , movement history  28 , circumstance history  27 , circumstance monitor condition master  25 , and item type master  27  are apparatuses or information similar to those of the circumstance information management system  10  shown in  FIG. 1  in the first embodiment. A circumstance-item association master  24  defines each of circumstance information measuring apparatuses attached to items or objects such as boxes that move together with items, as a set of measuring apparatus ID that is an identifier of a circumstance information input apparatus and an item ID that is an identifier of an item to be measured with the circumstance information measuring apparatus. If a circumstance information input apparatus is reused, the date and time at which the circumstance information measuring apparatus was attached to the item and the date and time at which the circumstance information input apparatus was removed from the item are recorded in addition to the measuring apparatus ID and the item ID.  
         [0084]     A circumstance history search program  92  generates item-by-item circumstance history  16 , which is a history of circumstances surrounding a particular item ID, from the movement history  28 , circumstance history  27 , and circumstance-item association master  24  and outputs it to an output apparatus  13  such as a printer or a display.  
         [0085]     A circumstance monitoring program  99  monitors the circumstance history  27  or the circumstance information  15  in accordance with circumstance monitor conditions for each type of item that is defined in the circumstance monitor condition master  25 , identifies an item that meets a condition from a item type master  26  that defines which item belongs to which type of item and from the movement history  28 , and outputs a warning  17  including a circumstance monitor condition, an item that meets the circumstance monitor condition, and information such as the location, and date and time to an output apparatus  13 .  
         [0086]     Processes of the circumstance history search program  92  and the circumstance monitoring program  99 , which will be described later, may be stored as programs in a computer-readable medium that can be read by a computer such as a personal computer and may be read from the recording medium and executed as needed.  
         [0087]     Referring to  FIG. 14 , processes in the circumstance information management system according to the second embodiment will be described with respect to an example in which the processes are applied to products distribution operations in which products are shipped from the production location, transported by a vehicle such as a truck, and then delivered to an outlet. Storage to and shipment from a warehouse described with reference to  FIG. 2  in the first embodiment may also be performed between the shipment from the production location and arrival at the outlet.  
         [0088]     While the second embodiment will be described with respect to temperature as circumstance information, it may be other circumstance information such as humidity, pressure, pH, acceleration, or odor. It may be the concentration of a particular substance such as carbon dioxide or carbon monoxide. In such a case, the circumstance information input apparatuses may be temperature sensors, pressure sensors, pH sensors, acceleration sensors, odor sensors, gas concentration sensors, or the like.  
         [0089]     It is assumed that each item  82  is equipped with a tag  56  containing an item ID  70  of the item  82  and a temperature sensor  57  that measures the temperature of the item  82  while moving. The tag  56  may be a machine-readable tag such as an electronic tag or a barcode, or may be a paper tag containing an item ID  70  visible to the human eye.  
         [0090]     When an item  82  is shipped from the production location  80 , the item ID  70  is read by a reader  58 , which is equivalent to a movement information input apparatus  11  shown in  FIG. 20 . The reader  58  reads the item ID recorded on the tag  56  and inputs or sends it to the circumstance information management system  18 . The reader  58  may be an electronic tag reader or a barcode reader, depending on the type of the tag  56 . Also, a human operator may read the item ID written on the tag  56  and input it through a keyboard.  
         [0091]     The reader  58  inputs reading dates and times as movement dates and times, a reader ID of the reader  58  as a movement location ID, and “Shipment” as the movement state in the circumstance information management system  18  as shipment information  71 , which is equivalent to the movement information  14  in  FIG. 20 . When receiving the shipment information  71 , the circumstance information management system  18  stores it in a movement history  28 .  
         [0092]      FIG. 8  shows an example of the movement history  28 . For example, the record denoted by reference numeral L 82  indicates that a reader with the reader ID “220” has scanned an item with the item ID “300” and stored information at the date and time “22:00 Jan. 2, 2005”.  
         [0093]     When the item  82  arrives at an outlet  81 , an item ID  73  is read by a reader  59  and is input in the circumstance information management system  18 , as in the shipment from the production location  80 , along with the read date and time, the ID of the reader  58  which is a movement location ID, and the movement state “Arrival” as arrival information  74  equivalent to the movement information  14  in  FIG. 20 . Record L 87  in  FIG. 8  represents an example in which an item with the item ID “300” arrived at the outlet  81  was scanned and stored by a reader with the reader ID “221” at “08:00 Jan. 3, 2005”.  
         [0094]     The temperature of the item  82  is measured at regular time intervals with a temperature sensor  57 , which is equivalent to a circumstance information input apparatus  12  shown in  FIG. 20 , attached to the item  82  or an object such as a box that moves together with the item  82 . The measurement may be performed every one second or every one hour. If the temperature sensor  57  measures a temperature of “−20° C.” at “00:00 Jan. 3, 2005”, the measured temperature “−20° C.”, the measurement date and time “00:00 Jan. 3, 2005” and a temperature sensor ID which is the identifier of the measuring apparatus are sent to the circumstance information management system  18  as temperature information  72  equivalent to the circumstance information  15  in  FIG. 20 . The temperature information  72  may be sent each time the temperature is measured or at predetermined time intervals through a mobile phone or satellite communication, or may be stored by the temperature sensor  57 , read by a reader  59  at the outlet  81  along with the item ID  73 , and sent to the circumstance information management system  18  together with arrival information  74 .  
         [0095]     When receiving the temperature information  72 , the circumstance information management system  18  stores it in a circumstance history  27 .  
         [0096]      FIG. 7  shows an example of the circumstance history  27 . Reference numeral L 78  in  FIG. 7  denotes temperature information  72  obtained by the temperature sensor with the temperature sensor ID “110” in the example described.  
         [0097]     Thus, the information is recorded in the movement history  28  which records the movement of items and in the circumstance history  27  which is a history of measurements of circumstances.  
         [0098]     The circumstance-item association master  24  according to the second embodiment will be described below. The circumstance monitor condition master  25  and the item type master  26  are the same as those in the first embodiment and therefore the description of which will be omitted.  
         [0099]      FIG. 4  shows an example of the circumstance-item association master  24 . For example, data L 41  defines that a circumstance information input apparatus with the measuring apparatus ID “110” is kept attached to an item with the item ID “300” or an object close to the item such as a box in the period between the attachment date and time “22:00 Jan. 2, 2005” and the removal date “08:00 Jan. 3, 2005” and the circumstances surrounding the item are measured with the circumstance information input apparatus during the period.  
         [0100]     Referring to the process flow shown in  FIG. 19 , a process of the circumstance history search program  92  will be described.  
         [0101]     At step S 30  in  FIG. 19 , the history of the movement of a particular item is retrieved from a movement history shown in  FIG. 8 . The item is specified by inputting the item ID “300” of the item in an item ID entry field  313  in a screen  312  shown in  FIG. 17 , for example, and pressing a search button  314 . When the item ID “300” is inputted as shown in the example, data L 82 , L 83 , L 86 , and L 87  in  FIG. 8  are retrieved as a result of the search.  
         [0102]     Then, at step S 31 , the circumstance-item association master  24  is searched to retrieve information indicating the circumstance information input apparatus attached to the item, its attachment date and time, and its removal date and time. Because the item ID is “300” in the example described, the measuring apparatus ID “110”, the attachment date and time “22:00 Jan. 2, 2005”, and the removal date and time “08:00 Jan. 3, 2005” are obtained from data L 41  with item ID “300” in the circumstance-item association master  24  shown in  FIG. 4 .  
         [0103]     Then, at step S 32 , circumstance values measured during the period between the date and time at which the circumstance information input apparatus identified at step S 31  was attached and the date and time at which it was removed are obtained from the circumstance history  27  and an item-by-item temperature history  75 , which includes information indicating a measuring apparatus (a temperature sensor in this example) and is equivalent to the item-by-item circumstance history  16  in  FIG. 20 , is sent to and displayed on a display  55 , which is equivalent to an output apparatus  13 . In the example described, data L 78 , L 79 , and L 710  that have the measuring ID “110” and measurement dates and times between the attachment date and time “22:00 Jan. 2, 2005” and the removal date “08:00 Jan. 3, 2005” are retrieved from the circumstance history  27  shown in  FIG. 7 .  FIG. 18  shows an exemplary item-by-item circumstance history screen  315  displayed on the display  55 .  
         [0104]     Referring to the process flow shown in  FIG. 15 , a process of the circumstance monitoring program  99  will be described. The process may be performed when temperature information  72  is recorded in the circumstance information management system  18  or may be performed later for each row in the circumstance history  27 . The process will be described here on the assumption that the measuring apparatus ID “110”, the measurement date and time “03:00 Jan. 3, 2005”, and the measured value “−10° C.” have been inputted as temperature information  72 .  
         [0105]     First, at step S 11 , the item ID of an item associated with the measuring apparatus ID inputted as the temperature information  72  is retrieved from the circumstance-item association master  24 . In the example described, the item ID  241  “300” is obtained from data L 41  in the circumstance-item association master  24  shown in  FIG. 4  that matches the conditions that the measuring apparatus ID  240  matches the measuring apparatus ID “110” in the temperature information  72  and that the measurement date and time “03:00 Jan. 3, 2005” in the temperature information  72  is between the attachment date and time  242  and the removal date and time  243 . If a removal date and time  243  is not registered, it may be determined that the apparatus has not yet been removed and that the measurement date and time in the temperature information  72  is later than the attachment date and time  242 .  
         [0106]     At step S 12 , the item type to which the item with the item ID obtained at step S 11  belongs to is obtained from the item type master  26 . In the example described, the item IDs  261  in the item type master  26  shown in  FIG. 6  is searched through for the item ID “300” obtained at step S 11  and the item type ID “41” is obtained from data L 61  that meets the search criteria.  
         [0107]     At step S 13 , a circumstance monitor condition for the item type obtained at step S 12  is retrieved from the circumstance monitor condition master  25 . In the example described, the item type IDs  250  in the circumstance monitor condition master  25  shown in  FIG. 5  are searched through for the item type ID “41” obtained at step S 12  and the condition L 52  that matches the search criteria is obtained.  
         [0108]     At step S 14 , the measured value in the temperature information  72  inputted is checked to determine whether it meets the circumstance monitor condition obtained at step S 13 . If it does, the process proceeds to step S 15 ; otherwise the process will end. In the example described, determination is made as to whether the measured value “−10° C.” is in the range between an upper-limit temperature of “−15° C.” and a lower-limit temperature of “−25° C.” in the circumstance monitor condition L 52 . Because the measured temperature “−10° C.” is higher than the upper-limit temperature “−15° C.”, the process proceeds to step S 15 .  
         [0109]     At step S 15 , a warning  76 , which is equivalent to the warning  17  shown in  FIG. 1 , indicating that the item obtained as a result of the process described above meets the circumstance monitor condition is sent to and displayed on the display  55 , which is equivalent to an output apparatus  13 .  FIG. 16  shows an exemplary warning screen  310  displayed on the display  55 .  
         [0110]     The present invention can be used in the distribution of any items such as food distribution in which the management of circumstance data such as temperature is important. Furthermore, the present invention can also be used to associate circumstances in rooms in a factory with items being manufactured and can find a wide range of applications, in addition to product distribution.  
         [0111]     Having described a preferred embodiment of the invention with reference to the accompanying drawings, it is to be understood that the invention is not limited to the embodiments and that various changes and modifications could be effected therein by one skilled in the art without departing from the spirit or scope of the invention as defined in the appended claims.