a milking arrangement according to an embodiment is partly disclosed in fig1 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 fig1 . 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 . 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 . 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 . 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 . 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 . 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 . 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 . 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 . 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 . 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 . 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 . 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 . 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 . 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 . 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 . 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 . 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 . 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 . 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 . 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 . 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 . 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 . 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 . 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 . 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 . 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 . 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 . 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 . 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 . 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 . 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 . 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 . especially , in milking arrangements wherein the replacement of exchangeable expendable parts is made fast and efficient , the above approaches may be suitable . 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 . 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 . with reference next to fig2 , 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 . 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 . 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 . 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 . 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 . 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 . 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 fig1 . 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 . 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 . it shall be appreciated that the above methods may be implemented in a large variety of milking arrangements .
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 .