Abstract:
An exchangeable expendable part of a milking arrangement includes an identification tag with data by which a model or a manufacturing date of the exchangeable expendable part is uniquely identified. The tag is readable by a reader arranged to repeatedly read the tag and to forward the readings to a computer system, whereby the computer system identifies the model and/or a manufacturing date of the part based on the readings; and, in response to the identified model and/or manufacturing date, i) alerts an operator, ii) monitors and/or controls the milking arrangement, and/or iii) makes the model and/or the manufacturing date of the part available to an operator. Exchangeable expendable parts include teat cup liners, cartridges including teat cup liners, and milk or vacuum tubes connected to teat cups.

Description:
TECHNICAL FIELD OF THE INVENTION 
       [0001]    The present invention relates generally to dairy farming. Particularly, the invention relates to a milking arrangement, a set of exchangeable parts for a milking arrangement, and a method for a milking arrangement. 
       DESCRIPTION OF RELATED ART AND BACKGROUND OF THE INVENTION 
       [0002]    In milking arrangements some parts, such as flexible teat cup liners, milk tubes, and pulsation tubes, may be expendable and thus exchangeable. Teat cup liners, for instance, come in a variety of models to suit the particular species, breed, size, or teat size of the animal to be milked. 
         [0003]    The expendable exchangeable parts are typically made of rubber or a polymer. The material of the expendable exchangeable parts deteriorates with the age and operation time and they thus have to be replaced at certain intervals. 
         [0004]    The replacement of teat cup liners is complicated and time-consuming and thus costly, and some dairy farmers are thus reluctant to replace the teat cup liners as often as recommended. 
         [0005]    WO 2013/095290 discloses a teat cup of a different construction, comprising a connector and a cartridge. The cartridge comprises a sleeve, having a first end and a second end, and a flexible teat cup liner mounted in the sleeve and having an inner space for receiving a teat. A pulsation chamber is formed in the cartridge. The connector is configured to connect a milk conduit to the cartridge. In such a teat cup the whole cartridge is replaced, instead of just the liner as in a conventional teat cup. While this permits the dairy farmer to take advantage of new, improved, molded inflations made of superior materials, it is also assumed that the replacement of such a cartridge is simpler and faster than replacing a conventional teat cup liner. 
       SUMMARY OF THE INVENTION 
       [0006]    However, still the dairy farmer may be hesitant to replace the teat cup liner as often as recommended. Further, the dairy farmer may not manually take actions to ensure that the replacement date is entered into the computer system of the milking arrangement, and thus the dairy farmer will not be reminded of the fact that it is time to replace the teat cup liners even if the computer system would have been equipped with an alarm clock functionality. 
         [0007]    Yet further, if the dairy farmer mounts a teat cup liner of a model which is incorrect, this can lead to damages of the milking arrangement, lower milk production, and potentially health problems among the animals. No means exist today that address this issue. 
         [0008]    It is therefore an object to provide a milking arrangement, a set of exchangeable parts, and a method, which alleviate the problems discussed above. 
         [0009]    It is a further object to provide such a milking arrangement, set, and method, by which the quality and quantity of milk production is optimized, and the animal treatment is improved. 
         [0010]    It is yet a further object to provide such a milking arrangement, set, and method, which are efficient, reliable, of reasonable cost, and easy to use. 
         [0011]    These objects, among others, are attained by the milking arrangements, the sets of exchangeable parts, and the methods as defined in the appended patent claims. 
         [0012]    In a first aspect there is provided a milking arrangement comprising milking equipment provided for milking animals; and a computer system provided for monitoring and/or controlling the milking equipment, wherein the milking equipment comprises a plurality of exchangeable expendable parts in the form of teat cup liners or cartridges including teat cup liners and/or milk or vacuum tubes connected to teat cups of the milking equipment, wherein at least one of said exchangeable expendable parts comprises an identification tag, e.g. an RFID (radio frequency identification) tag, comprising data, by which the model and/or a manufacturing date of said exchangeable expendable part can be uniquely identified; and the milking arrangement further comprises a reader, e.g. an RFID reader, operatively connected to the computer system and arranged to repeatedly read the data of the identification tag of said exchangeable expendable part and to forward the readings of the identification tags of said exchangeable expendable part to the computer system. 
         [0013]    The computer system is configured to identify the model and/or a manufacturing date of said exchangeable expendable part based on the readings; and, in response to the identified model and/or manufacturing date, (i) to alert an operator and/or (ii) to monitor and/or control the milking equipment, and/or (iii) to make the model and/or a manufacturing date of said exchangeable expendable part available to an operator. 
         [0014]    In a second aspect there is provided a set of exchangeable expendable parts in the form of teat cup liners or cartridges including teat cup liners and/or milk or vacuum tubes connected to teat cups for a milking arrangement comprising milking equipment provided for milking animals; a computer system provided for monitoring and/or controlling the milking equipment; and a reader, e.g. an RFID reader, operatively connected to the computer system and arranged to repeatedly read identification tags, e.g. RFID tags, and to forward the readings to the computer system. At least one of said exchangeable expendable parts comprises an identification tag, e.g. an RFID tag, comprising data, by which the model and/or a manufacturing date of said exchangeable expendable part can be uniquely identified. 
         [0015]    In a third aspect there is provided a method for a milking arrangement comprising milking equipment provided for milking animals; and a computer system provided for monitoring and/or controlling the milking equipment, wherein the milking equipment comprises a plurality of exchangeable expendable parts in the form of teat cup liners or cartridges including teat cup liners and/or milk or vacuum tubes connected to teat cups of the milking equipment. The method features the steps of providing at least one of the exchangeable expendable parts with an identification tag, e.g. an RFID tag, comprising data, by which the model and/or a manufacturing date of said exchangeable expendable part can be uniquely identified, repeatedly reading the identification tag of said exchangeable expendable part by a reader, e.g. an RFID reader, operatively connected to the computer system, and forwarding the readings of the identification tag of said exchangeable expendable part to the computer system. 
         [0016]    The model and/or a manufacturing date of said exchangeable expendable part is uniquely identified based on the readings; and, in response to the identified model and/or manufacturing date, (i) an operator is alerted, (ii) the milking equipment is monitored and/or controlled, and/or (iii) the model and/or a manufacturing date of said exchangeable expendable part is made available to an operator. 
         [0017]    The identification tag may comprise data, such as e.g. a manufacturer serial number and/or a manufacturer batch number by which an individual item, and/or a manufactured group of a certain model, of the exchangeable expendable part can be uniquely identified, and the computer system may be configured to identify the individual item, and/or the manufactured group of a certain model, of the exchangeable expendable part based on the readings. 
         [0018]    The above aspects open up a number of possible applications. The computer system may automatically check that exchangeable expendable parts of correct models have been mounted such that the milking arrangement will not be operated with improper equipment, since this would risk causing a lower milk production, failure of the milking arrangement, and/or health problems among the animals. The computer system may additionally, or alternatively, check that the exchangeable expendable parts are not too old or that the operation times for the exchangeable expendable parts are not too long such that the milking arrangement will not be operated with too old or too used exchangeable expendable parts, since this would also risk causing a lower milk production, failure of the milking arrangement, and/or health problems among the animals. 
         [0019]    If the identification tag does not in itself comprise the model and/or the manufacturing date of the exchangeable expendable part, the computer system may comprise a database of exchangeable expendable parts, in which the data of the identification tag of the exchangeable expendable part is associated with a model and/or a manufacturing date of the exchangeable expendable part, such that the computer system is capable of retrieving the model and/or the manufacturing date of an exchangeable expendable part after having received a reading of the data of the identification tag of the exchangeable expendable part. 
         [0020]    In one embodiment, the computer system may control the milking equipment, in particular milking or vacuum parameters used during milking, in response to the model and/or manufacturing date of at least one exchangeable expendable part. This enables the adaptation of the milking process to the model and/or age of the milking equipment. 
         [0021]    In another embodiment, the computer system may (i) store information regarding a desired model of the exchangeable expendable part, (ii) check whether the model of the exchangeable expendable part corresponds to the desired model, and (iii) if the model of the exchangeable expendable part does not correspond to the desired model, control the alerting means to alert an operator of the milking arrangement that the model of the exchangeable expendable part does not correspond to the desired model. Hereby, an automatic system may be realized, which alerts an operator as soon as a critical exchangeable expendable part of a non desired, i.e. incorrect, model has been mounted. 
         [0022]    Additionally, or alternatively, if the above condition is obtained, the computer system may stop the milking equipment from being used until the exchangeable expendable part has been exchanged for an exchangeable expendable part which corresponds to the desired model. This may ensure that the milking equipment will never be operated with a critical exchangeable expendable part of a non desired, i.e. incorrect, model. This ensures that the risk for a lower milk production, failure of the milking arrangement, and/or health problems among the animals due to use of a critical exchangeable expendable part of an incorrect model can entirely be avoided. 
         [0023]    In yet another embodiment, the computer system may control the robot to change an exchangeable expendable part in response to the model and/or manufacturing date of that exchangeable expendable part. This enables the milking arrangement to automatically change an exchangeable expendable part so as to adapt the model or age of the exchangeable expendable part in order to optimize milking equipment operation. In this way, it is e.g. possible to use different types of teat cup liner for the milking of different animals. 
         [0024]    In one version, the computer system may (i) record the operation pattern of the milking equipment, (ii) record the points in time of the received readings, and (iii) repeatedly calculate an operation time, e.g. expressed as number of milkings or hours in operation, for the exchangeable expendable part based on the operation pattern for the milking equipment and the points in time of the received readings. This can be used in a number of embodiments. 
         [0025]    In one embodiment, the computer system may control the milking equipment, in particular milking or vacuum parameters used during milking, in response to the repeatedly calculated operation time for the exchangeable expendable part. This enables the adaptation of the milking process to the operation time for the milking equipment, which may in turn enable a longer usage of the equipment before it needs to be exchanged. 
         [0026]    In another embodiment, the computer system may comprise alerting means arranged to alert an operator of the milking arrangement in response to the repeatedly calculated operation time for the exchangeable expendable part. 
         [0027]    For instance, the computer system may (i) store information regarding a desired operation time for the exchangeable expendable part, (ii) check whether the repeatedly calculated operation time for the exchangeable expendable part exceeds the desired operation time, and (iii) if the repeatedly calculated operation time exceeds the desired operation time, control the alerting means to alert an operator of the milking arrangement that the operation time for the exchangeable expendable part exceeds the desired operation time. Hereby, an automatic system may be realized, which alerts an operator as soon as the operation time for a critical exchangeable expendable part exceeds a desired maximum operation time. 
         [0028]    Additionally, if the above condition is obtained, the computer system may stop the milking equipment from being used until the exchangeable expendable part has been exchanged for an exchangeable expendable part having no repeatedly calculated operation time, or at least a repeatedly calculated operation time which is lower than the desired operation time. This may ensure that the milking equipment will never be operated with a critical exchangeable expendable part having too long operation time. This ensures that the risk for a lower milk production, failure of the milking arrangement, and/or health problems among the animals due to use of a too much used critical exchangeable expendable part can entirely be avoided. 
         [0029]    In yet another embodiment, the computer system may control the robot to change the exchangeable expendable part in response to the repeatedly calculated operation time for that exchangeable expendable part. This enables the milking arrangement to automatically change the exchangeable expendable part depending on the automatically and repeatedly calculated operation time for said exchangeable expendable part. 
         [0030]    It shall be appreciated that the present invention is not only applicable to a single exchangeable expandable part, but can be made applicable to each, or at least one of a plurality, of the exchangeable expendable parts of a milking system. 
         [0031]    Yet further, the computer system may store quantities of milk milked by the milking arrangement and/or properties of the animals milked by the milking arrangement and may control (i) the milking equipment, in particular milking or vacuum parameters used during milking, in response to the stored quantities of milk and/or properties of the animals, (ii) the alerting means to alert an operator of the milking arrangement, e.g. by informing the operator that one or more of the exchangeable expendable parts need to be replaced, in response to the stored quantities of milk and/or properties of the animals, or (iii) the robot to change one or more of the exchangeable expendable parts in response to the stored quantities of milk and/or properties of the animals. 
         [0032]    For instance, if the quantities of milk milked by the milking arrangement drops, this may be an indication that the exchangeable expendable parts, especially the teat cup liners, used is not the optimum solution and that they should be replaced for some reason, e.g. due to their model number, age, or operation time. The quantities of milk milked by the milking arrangement may be stored, together with the model numbers of the exchangeable expendable parts used, to form a database of historical data. From such data, an optimum choice of models of the exchangeable expendable parts can be selected in order to optimize the milk production and ensure high yields of milk. 
         [0033]    Typically, different exchangeable expendable parts may fit different animals. The stored properties of the animals milked by the milking arrangement can be any properties related to the species, breed, age, health, weight, size, shape, teat size, and/or teat shape of the animals. Then, the alerting or the replacement of one or more exchangeable expendable parts may be performed if the properties for an animal or group of animals to be milked differ from the properties for which the one or more exchangeable expendable parts are fitted or adapted. If the milking arrangement is used for milking a large number of animals, these may be grouped and milked together based on the above properties such that the alerting or the replacement of one or more exchangeable expendable parts can be performed between the milking of two different groups of animals. 
         [0034]    Further, if the stored properties of the animals milked by the milking arrangement are related to the health of the animals, the alerting or the replacement of one or more exchangeable expendable parts may be performed in response to the stored properties of the animals milked by the milking arrangement indicating that the health of the animals is deteriorated, which could be caused by the use of exchangeable expendable parts of improper models. 
         [0035]    The present invention provides means for enabling replacement of exchangeable expendable parts of the milking arrangement including the flexible teat cup liners when recommended, e.g. when they are too old or when they have been used too much, but also when it is detected that incorrect models of the exchangeable expendable parts have been installed. This may be highly important to avoid risks of damaging the milking arrangement and hurting the animals or at least to avoid risks of deteriorated operation of the milking arrangement. Further, guarantees and warranties may only be valid if the milking arrangement is operated correctly, i.e. with exchangeable expendable parts of specified models and having manufacturing dates or hours of operation within specified intervals. 
         [0036]    Further characteristics of the invention, and advantages thereof, will be evident from the detailed description of preferred embodiments of the present invention given hereinafter, and the accompanying  FIGS. 1-2 , which are given by way of illustration only and thus are not limitative of the present invention. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0037]      FIG. 1  illustrates schematically main components of a milking arrangement. 
           [0038]      FIG. 2  is a flow scheme of a method for a milking arrangement. 
       
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
       [0039]    A milking arrangement according to an embodiment is partly disclosed in  FIG. 1  and comprises milking equipment  11  provided for milking animals, wherein the milking equipment  11  comprises teat cups  12 , of which one is illustrated attached to a teat  14  of an animal in  FIG. 1 . Each teat cup  12  comprises a rigid teat cup shell  12   a , a flexible teat cup liner  12   b  (or cartridge including a flexible teat cup liner), at least one milk tube  13   a  connecting the interior of the teat cup liner to a milking vacuum, and at least one pulsation vacuum tube  13   b  connecting the annular space  12 C between the teat cup liner  12   b  and the teat cup shell  12   a  to a pulsating vacuum. The flexible teat cup liners  12   b  (or cartridges including flexible teat cup liners), the at least one milk tube  13   a , and the at least one pulsation vacuum tube  13   b , which are generally made of rubber and/or polymers, or similar, are referred to as exchangeable expendable parts in this text. This means that these parts are being expended and have to be exchanged from time to time, i.a., due to the aging of the materials of the exchangeable expendable parts, which may cause malfunctioning or stopped operation of the milking equipment  11 . 
         [0040]    An example of the mentioned exchangeable cartridge including a flexible teat cup liner is referred to as a teat cup in WO 2013/095290, the contents of which being hereby incorporated by reference. 
         [0041]    The milking equipment  11  may further include a vacuum pump, a pulsator, and valves (not illustrated) for providing the milking vacuum and the pulsating vacuum to the teat cups  12 , a receiving vessel (not illustrated) for receiving the milked milk, and a milk meter (not illustrated) for measuring the quantity of the milked milk. 
         [0042]    The milking arrangement may further comprise a teat cup magazine  15  for storing the teat cups  12  when they are not attached to the teats  14  of an animal, a robot  16  for attaching the teat cups  12  to the teats  14  of animals to be milked, and a computer system  17  for monitoring and/or controlling the milking equipment ii. The computer system  17  comprises a processor  17   a , a memory  17   b , and alerting or outputting means  17   c  in the form of a display for visual alerts or outputs and/or a speaker for audio alerts or outputs. One or more suitable computer programs  17   d  are stored in the memory  17   b  and comprise computer program code or instructions that, when executed by the processor  17   a , cause the computer system  17  to monitor and/or control the milking equipment  11  as disclosed in this text. 
         [0043]    Each of the exchangeable expendable parts disclosed above (the flexible teat cup liners  12   b  or cartridges including flexible teat cup liners, the milk tube  13   a , and the pulsation vacuum tube  13   b ) is provided with an identification tag  18   a - c  comprising data, by which the model and/or a manufacturing date of the exchangeable expendable part  12   b ,  13   a - b  can be uniquely identified, and the milking arrangement further comprises a reader  19  operatively connected to the computer system  17  and arranged to repeatedly read the identification tag  18   a - c  of the exchangeable expendable part  12   b ,  13   a - b  and to forward the readings of the identification tag  12   a  - c  of the exchangeable expendable part  12   b ,  13   a - b  to the computer system  17 . 
         [0044]    The identification tag  18   a - c  may be an RFID (radio frequency identification) tag and the reader  19  may be an RFID reader. Alternatively, the identification tag  18   a - c  may be a visual tag, e.g. a bar code, and the reader  19  may be a visual tag reader, e.g. a bar code reader. 
         [0045]    The reader  19  may, at least for the purpose of reading the identification tag  18   a  of the flexible teat cup liner  12   b  (or the cartridge including a flexible teat cup liner), be arranged to read the identification tag  18   a  repeatedly when a teat cup  12  of the milking equipment  11  is arranged in the teat cup magazine  15 , is held by the robot  16 , or is attached to a teat  14  of an animal. It shall be appreciated that the reader  19  may be located, or movable, suitably in order to read all identification tags  18   a - c  present at the exchangeable expendable parts  12   b ,  13   a - b . Alternatively, the milking arrangement may comprise more than one reader  19  for the purpose of reading identification tags  18   a - c  repeatedly and forward the readings to the computer system  17 . 
         [0046]    The repetition rate for the readings may e.g. be once each time the milking equipment  11  is used for milking, or less frequently such as at least once an hour, twice a day, or once a day. The repeated readings may also take place substantially continuously. 
         [0047]    The identification tag  18   a - c  of an expendable part  12   b ,  13   a - b  may comprise item identifying data, such as e.g. a manufacturer serial number, uniquely identifying the individual item of the exchangeable expendable part, batch identifying data, such as e.g. a manufacturer batch number, uniquely identifying a manufactured group of a certain model of the exchangeable expendable part, model identifying data, such as e.g. a manufacturer model number, uniquely identifying the model of the exchangeable expendable part, and/or manufacturing date data uniquely identifying the manufacturing date of the exchangeable expendable part. 
         [0048]    The computer system  17  is configured to identify the item, batch, model and/or manufacturing date of the exchangeable expendable part  12   b ,  13   a - b  based on the readings. 
         [0049]    Alternatively, instead of having the model and/or the manufacturing date of the exchangeable expendable part  12   b ,  13   a - b  in the identification tag  18   a - c , the computer system  17  may comprise a database  17   e  of exchangeable expendable parts  12   b ,  13   a - b , in which the identification tag  18   a - c  of an exchangeable expendable part  12   b ,  13   a - b  is associated with a model and/or a manufacturing date of the exchangeable expendable part  12   b ,  13   a - b , such that the computer system  17  is capable of retrieving the model and/or the manufacturing date of an exchangeable expendable part  12   b ,  13   a - b  after having received a reading of the data of the identification tag  18   a - c  of the exchangeable expendable part. 
         [0050]    The computer system  17  may be arranged to control the milking equipment  11 , in particular milking parameters used during milking, such as e.g. milking vacuum, pulsation vacuum, pulsation rate, and/or pulsation frequency, in response to the item, batch, model, and/or manufacturing date of the exchangeable expendable part  12   b ,  13   a - b.    
         [0051]    In particular, the aging of the teat cup liners  12   b  may cause them to be less elastic or flexible, which may call for different parameter settings. Further, teat cup liners  12   b  of different manufacturer models may call for different parameter settings. 
         [0052]    Alternatively, or additionally, the computer system  17  may control the alerting means  17   c  to alert an operator of the milking arrangement in response to the item, batch, model, and/or manufacturing date of the exchangeable expendable part  12   b ,  13   a - b.    
         [0053]    Yet alternatively, or yet additionally, the computer system  17  may simply store and make the item, batch, model and/or the manufacturing date of the exchangeable expendable part  12   b ,  13   a - b  available to an operator of the computer system  17 . 
         [0054]    In one embodiment, the computer system  17  is arranged to store information regarding a desired model of the exchangeable expendable part  12   b ,  13   a - b  in its memory  17   b , check whether the model of the exchangeable expendable part  12   b ,  13   a - b  corresponds to the desired model, and if the model of the exchangeable expendable part  12   b ,  13   a - b  does not correspond to the desired model, control the alerting means  17   c  to alert an operator of the milking arrangement that the model of the exchangeable expendable part  12   b ,  13   a - b  does not correspond to the desired model. 
         [0055]    In another embodiment, the computer system  17  is arranged to store information regarding a desired model of the exchangeable expendable part  12   b ,  13   a - b  in its memory  17   b , check whether the model of the exchangeable expendable part  12   b ,  13   a - b  corresponds to the  desired model, and if the model of the exchangeable expendable part  12   b ,  13   a - b  does not correspond to the desired model, stop the milking equipment  11  from being used until the exchangeable expendable part  12   b ,  13   a - b  has been exchanged for an exchangeable expendable part of the desired model. 
         [0056]    Further, in one embodiment, the computer system  17  is arranged to control the robot  16  to change an exchangeable expendable part  12   b ,  13   a - b  in response to the model and/or manufacturing date of that exchangeable expendable part  12   b ,  13   a - b , e.g. if the model is not correct and/or if the manufacturing date is too old. 
         [0057]    The computer system  17  may be arranged to record the operation pattern for the milking equipment  11 , record the points in time of the received readings, and repeatedly calculate an operation time, e.g. expressed as number of milkings or hours in operation, for an exchangeable expendable part  12   b ,  13   a - b  based on the operation pattern for the milking equipment  11  and the points in time of the received readings. The repeatedly calculated operation time can then be used in any of the following manners. 
         [0058]    The computer system  17  may be arranged to control the milking equipment  11 , in particular milking parameters such as those exemplified above used during milking, in response to the repeatedly calculated operation time for an exchangeable expendable part  12   b ,  13   a - b . In particular, a long operation time for a teat cup liner  12   b  may cause it to be less elastic or flexible, which may call for a different parameter setting. If the milking parameters can be adapted in this way, this may enable a longer usage of the exchangeable expendable parts  12   b ,  13   a - b.    
         [0059]    Alternatively, or additionally, the computer system  17  may be arranged to control the alerting means  17   c  to alert an operator of the milking arrangement in response to the repeatedly calculated operation time for an exchangeable expendable part  12   b ,  13   a - b.    
         [0060]    In one exemplary embodiment, the computer system  17  may be arranged to store information regarding a desired operation time for an exchangeable expendable part  12   b ,  13   a - b  in its memory  17   b , check whether the repeatedly calculated operation time for the exchangeable expendable part  12   b ,  13   a - b  exceeds the desired operation time, and if the repeatedly calculated operation time exceeds the desired operation time, control the alerting means  17   c  to alert an operator of the milking arrangement that the operation time for the exchangeable expendable part  12   b ,  13   a - b  exceeds the operation time. Hereby, the operator can be alerted that the exchangeable expendable part  12   b ,  13   a - b  needs to be replaced. 
         [0061]    In another exemplary embodiment, the computer system  17  may be arranged to store information regarding a desired operation time for an exchangeable expendable part  12   b ,  13   a - b  in its memory  17   b , check whether the repeatedly calculated operation time for the exchangeable expendable part  12   b ,  13   a - b  exceeds the desired operation time, and if the repeatedly calculated operation time exceeds the desired operation time, stop the milking equipment from being used until the exchangeable expendable part has been exchanged for an exchangeable expendable part  12   b ,  13   a - b  having no repeatedly calculated operation time, or at least a repeatedly calculated operation time which is lower than the desired operation time. Hereby, it can be ensured that the milking equipment is not operated until the exchangeable expendable part  12   b ,  13   a - b  that needs to be replaced, indeed has been replaced. 
         [0062]    Further, in another embodiment, the computer system  17  may be arranged to control the robot  16  to change an exchangeable expendable part  12   b ,  13   a - b  in response to the repeatedly calculated operation time for that exchangeable expendable part. Hereby, the milking arrangement can automatically replace an exchangeable expendable part  12   b ,  13   a - b  that needs to be replaced. 
         [0063]    In yet another embodiment, the computer system  17  may store quantities of milk milked by the milking arrangement and/or properties of the animals milked by the milking arrangement in its memory  17   b , wherein the computer system  17  may be arranged to control the milking equipment  11 , in particular milking parameters used during milking, e.g. the ones disclosed above, in response to the stored quantities of milk and/or properties of the animals, the computer system  17  may be arranged to control the alerting means  17   c  to alert an operator of the milking arrangement, e.g. by informing the operator that an exchangeable expendable part  12   b ,  13   a - b  needs to be replaced, in response to the stored quantities of milk and/or properties of the animals, or the computer system  17  may be arranged to control the robot  16  to change an exchangeable expendable part  12   b ,  13   a - b  in response to the stored quantities of milk and/or properties of the animals. 
         [0064]    The alerting or the replacement of one or more exchangeable expendable parts  12   b ,  13   a - b  based on stored quantities of milk milked by the milking arrangement can be implemented in any of the following exemplary embodiments. 
         [0065]    If the quantities of milk milked by the milking arrangement drops, this may be an indication that the exchangeable expendable parts  12   b ,  13   a - b , especially the teat cup liners  12   b , used is  not the optimum solution and that they should be replaced. 
         [0066]    Further, the quantities of milk milked by the milking arrangement may be stored, together with the model numbers of the exchangeable expendable parts  12   b ,  13   a - b  used, to form a database of historical data. From such data, an optimum choice of models of the exchangeable expendable parts  12   b ,  13   a - b  can be selected in order to optimize the milk production and ensure high yields of milk. 
         [0067]    If many milking arrangements are connected together, a large database can be formed containing quantities of milk milked together with the model numbers of the exchangeable expendable parts  12   b ,  13   a - b  used for different animal herds, which can be used for optimum choices of model numbers of the exchangeable expendable parts  12   b ,  13   a - b . Based on such a database, new recommended uses of exchangeable expendable parts  12   b ,  13   a - b  of different models can be made e.g. by the manufacturer. 
         [0068]    The alerting or the replacement of exchangeable expendable parts  12   b ,  13   a - b  based on stored properties of the animals milked by the milking arrangement can be implemented in any of the following exemplary embodiments. 
         [0069]    Typically, different exchangeable expendable parts  12   b ,  13   a - b , at least when relating to teat cup liners  12   b , may fit different animals. The stored properties of the animals milked by the milking arrangement can be any properties related to the species, breed, age, health, weight, size, shape, teat size, and/or teat shape of the animals. Then, the alerting or the replacement of exchangeable expendable parts  12   b ,  13   a - b  may be performed if the properties for an animal or group of animals to be milked differ from the properties for which said exchangeable expendable parts  12   b ,  13   a - b  are fitted or adapted. 
         [0070]    If the milking arrangement is used for milking a large number of animals, these may be grouped and milked together based on the above properties such that the alerting or the replacement of exchangeable expendable parts  12   b ,  13   a - b  can be performed between the milking of two different groups of animals. 
         [0071]    Especially, in milking arrangements wherein the replacement of exchangeable expendable parts is made fast and efficient, the above approaches may be suitable. 
         [0072]    Further, if the stored properties of the animals milked by the milking arrangement are related to the health of the animals, the alerting or the replacement of exchangeable expendable parts  12   b ,  13   a - b  may be performed in response to the stored properties of the animals milked by the milking arrangement indicating that the health of the animals is deteriorated, which could be caused by use of exchangeable expendable parts  12   b ,  13   a - b  of  improper models. 
         [0073]    In one further aspect the invention relates to a set of exchangeable expendable parts  12   b ,  13   a - b  for a milking arrangement as disclosed above, wherein each of the exchangeable expendable parts  12   b ,  13   a - b  comprises an identification tag  18   a - c  as disclosed above. 
         [0074]    With reference next to  FIG. 2 , which is a flow scheme of a method for a milking arrangement comprising milking equipment provided for milking animals, and a computer system provided for monitoring and/or controlling the milking equipment, wherein the milking equipment comprises a plurality of exchangeable expendable parts, further aspects of the invention will be disclosed. 
         [0075]    According to the method, at least one exchangeable expendable part is, in a step  21 , provided with an identification tag, e.g. an RFID (radio frequency identification) tag, comprising data, by which the item, batch, model and/or a manufacturing date of the exchangeable expendable part can be uniquely identified, the identification tag is, in a step  22 , repeatedly read by a reader, e.g. an RFID reader, operatively connected to the computer system, and the readings of the identification tag are, in a step  23 , forwarded to the computer system, and the item, batch, model, and/or a manufacturing date of the exchangeable expendable part is identified based on the readings. 
         [0076]    Various routes may then be taken. 
         [0077]    In a first route, three different steps may be performed independently of one another. In one step  24 , the milking equipment, in particular milking parameters used during milking such as e.g. those disclosed above, is controlled in response to the item, batch, model, and/or manufacturing date of the exchangeable expendable part. In another step  25 , an operator of the milking arrangement is alerted in response to the item, batch, model, and/or manufacturing date of the exchangeable expendable part. In yet another step  26 , the exchangeable expendable part is exchanged in response to the item, batch, model, and/or manufacturing date of that exchangeable expendable part. 
         [0078]    In a second route, the operation pattern for the milking equipment is, in a step  27 , recorded, the points in time of the received readings are, in step  28 , recorded, and an operation time, e.g. expressed as number of milkings or hours in operation, for the exchangeable expendable part is, in a step  29 , repeatedly calculated based on the operation pattern for the milking equipment and the points in time of the received readings. 
         [0079]    Thereafter, three different steps may be performed independently of one another. In one step  30 , the milking equipment, in particular milking parameters, such as those disclosed above, used during milking, is controlled in response to any of the repeatedly calculated operation times. In another step  31 , an operator of the milking arrangement is alerted in response to any of the repeatedly calculated operation times. In yet another step  32 , the exchangeable expendable part is exchanged in response to the repeatedly calculated operation time for that exchangeable expendable part. 
         [0080]    In a further route, the uniquely identified item, batch, model, and/or manufacturing date of the exchangeable expendable part is simply stored and made available to an operator at any suitable occasion, such as during a manual check. 
         [0081]    It shall be appreciated that above methods and routes may be modified e.g. by incorporating any of the functions performed by the milking arrangement as disclosed with reference to  FIG. 1 . 
         [0082]    In particular, it shall be appreciated that according to one method, information regarding a desired model of an exchangeable expendable part is stored, it is checked whether the model of that exchangeable expendable part (as found in the data of the identification tag or retrieved based on data of the identification tag) corresponds to the desired model, and if the model of the exchangeable expendable part does not correspond to the desired model, an operator of the milking arrangement is alerted of the fact that the model of the exchangeable expendable part does not correspond to the desired model, or the milking equipment is stopped from being used until the exchangeable expendable part has been exchanged for an exchangeable expendable part of the desired model. 
         [0083]    According to another method, information regarding a desired operation time for an exchangeable expendable part is stored, it is checked whether the repeatedly calculated operation time for that exchangeable expendable part (obtained as disclosed above) exceeds the desired operation time, and if the repeatedly calculated operation time for the exchangeable expendable part exceeds the desired operation time, an operator of the milking arrangement is alerted of the fact that the operation time for the exchangeable expendable part exceeds the desired operation time, or the milking equipment is stopped from being used until the exchangeable expendable part has been exchanged for an exchangeable expendable part having no repeatedly calculated operation time, or at least a repeatedly calculated operation time which is lower than the desired operation time. 
         [0084]    It shall be appreciated that the above methods may be implemented in a large variety of milking arrangements.