Abstract:
A method for maintaining a system consisting of a plurality of components, comprises the steps of collecting maintenance information for each component of the system for which maintenance information is available; providing a maintenance schedule for components of the system; operating the system; and maintaining the system wherein during scheduled maintenance of a component information about the status of that component is acquired, during a failure of a component information about the failure of that component is acquired, and modifying the maintenance schedule according to the acquired information.

Description:
TECHNICAL FIELD 
       [0001]    The present application relates to automation systems and in particular to the optimized maintenance of such a system. 
       BACKGROUND OF THE INVENTION 
       [0002]    In modern factories or plants, engineering systems are provided to define processing steps in manufacturing and/or controlling certain process steps within the system. To this end, these engineering systems usually comprise a plurality of mechanical and/or electrical components, such as process technology field devices, control devices, drives, sensors, microprocessors, personal computers, software, etc. Each component often consists of hardware and software/firmware, additional aids for configuration, parameterization, and diagnosis, as well as information for operating and maintaining the component. Such information is provided by the specific vendor of the component or if the component is designed in house, by the specific engineering team. 
         [0003]    System manufacturers combine these components provided by specific vendors if necessary with their own components to design and build complex automation systems. The operator of such a designed system relies on the specific information provided by the system manufacturer and vendors to perform the required steps for maintaining the system operable. The most critical factor in operating automation systems is down time due to failure of a component. Therefore, maintaining the system operable is one of the most important tasks of a system operator. Specific maintenance teams monitor the system and repair specific components in case of a system failure. However, to keep down time at a minimum, preventive maintenance is required. Thus, failure can be avoided by exchanging specific parts according to a maintenance plan or scheme. Such a scheme or plan is simply defined according to the information provided by the system designer or vendor of a component which informs, for example, how often a specific part should be replaced. 
         [0004]    Nevertheless, many factors influence the operability of specific parts of a complex system. Thus, a maintenance scheme/plan as described above is far from being optimized and does not take specific influencing factors into account. For example, prescribed maintenance intervals might be too long or too short due to the specific design of the system or specific usage of devices. Hence, either avoidable system failure or unnecessary maintenance may occur, thus, increasing operating costs of the respective system. 
       SUMMARY OF THE INVENTION 
       [0005]    A method for maintaining a system consisting of a plurality of components, according to an exemplary embodiment of the invention comprises the steps of collecting maintenance information for each component of the system for which maintenance information is available; providing a maintenance schedule for components of the system; operating the system; and maintaining the system wherein during scheduled maintenance of a component information about the status of that component is acquired, during a failure of a component information about the failure of that component is acquired, and modifying the maintenance schedule according to the acquired information. 
         [0006]    The method may further comprise the step of determining maintenance information for components of the system for which no maintenance information is available. The information acquired during a scheduled maintenance may indicate that a service interval is too long, correct, or too short. The step of modifying may include the step of adjusting the service interval. The method may further comprise the step of determining information about interrelationship of components. The method further may comprise the step of determining information about environmental conditions of a location of at least one component. The method may further comprise the step of providing feedback information for a system designer. The method may further comprise the step of providing feedback information for a component manufacturer. The feedback information can be automatically generated via an electronic messaging system. 
         [0007]    A system for optimizing system maintenance according to another exemplary embodiment comprises a plurality of components; a data network coupling the plurality of components; and a maintenance unit for collecting and processing information generated during normal processing as well as during maintenance of components of the system according to a predefined maintenance schedule, wherein the predefined maintenance schedule is modified by the maintenance tool according to the processed information. 
         [0008]    The information may include maintenance information and/or normal processing information. Each component may comprise a memory unit for storing the maintenance information. The memory unit may store information for the component itself and for subordinated components. The system may further comprise means for generating electronic messages including the collected maintenance information and for providing a vendor and/or system designer with the electronic message. The system may further comprise sensors for sensing environmental conditions of a component. 
         [0009]    A method for designing and operating a system consisting of a plurality of components according to another exemplary embodiment of the present invention comprising the steps of designing a system using a plurality of components; collecting maintenance information for each component of the system; scheduling maintenance service for components of the system; operating the system; maintaining the system wherein during scheduled maintenance of a component information about the status of that component is acquired, during a failure of a component information about the failure of that component is acquired, and modifying the maintenance schedule according to the acquired information. At least one component can be provided by an external vendor or component manufacturer. The method may further comprise the step of determining maintenance information for components of the system for which no maintenance information is available. The information acquired during a scheduled maintenance may indicate any kind of deviation from a predefined status. The deviation may indicate that a service interval is too long, correct, or too short, and wherein the step of modifying includes the step of adjusting the service interval. The method may further comprise the step of determining information about interrelationship of components. The method may further comprise the step of determining information about environmental conditions of a location of at least one component. The method may further comprise the step of providing feedback information for a system designer. The method may further comprise the step of providing feedback information for a vendor or component manufacturer. The feedback information can be automatically generated via an electronic messaging system. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]      FIG. 1  shows an exemplary automation system according to the prior art; 
           [0011]      FIG. 2  shows a first exemplary flow chart of a system design and operation according to the present invention; 
           [0012]      FIG. 3  shows an exemplary embodiment of an automation system according to the present invention; 
           [0013]      FIG. 4  shows a second exemplary flow chart of a system design and operation according to the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0014]      FIG. 1  shows a conventional automation system consisting of an engineering system  100  coupled with a control unit  110  and a plurality of components  130 - 170 , for example as shown component A, B, C. In this exemplary system, component B further comprises sub-components B 1  and B 2 . Each component  130 - 170  might be provided by a different vendor and might comprise specific performance characteristics. Each vendor might recommend a certain maintenance plan and depending on the type of component a certain replacement schedule for specific parts, for example, wear and tear elements. The respective maintenance personnel will, thus, follow these instructions regardless of the overall characteristics of the entire system. Thus, certain maintenance services could be performed too late or too early. In addition, no feedback will generally be provided to the vendor or system designer. The maintenance personnel might at most adjust the maintenance schedule for the specific part. Nevertheless, any influence of the specific part and its specific needs on the entire system will be completely neglected. 
         [0015]    Thus, according to the present invention, a new approach for an improved method and tool for optimized maintenance is proposed. For example,  FIG. 2  shows a flow chart of specific steps in the design and operation of a system consisting of a plurality of independent and/or dependent components. In a first step  200 , the manufacturer of, for example, an automation system, designs the system using a plurality of, e.g., standard components, customized standard components, and/or specifically designed components. In step  210 , these components and their specific properties are defined using, if necessary, external information, for example, provided by the respective vendor as indicated with arrows  280 . According to this information, once the overall system is designed, a specific maintenance schedule/plan is defined in the following steps  220  and  230 . To this end, specific information about each component is collected in step  220  using, for example, external information about specific properties, wear and tear of each component, and recommended maintenance intervals and other maintenance data as indicated by arrows  270 . If no information is available, then the operator/user may define a custom maintenance schedule/plan if the respective component requires maintenance. In step  230 , these data are stored in a custom maintenance data base and used to design a custom maintenance scheme/plan taking into consideration the respective inherent properties of each component as well as their particular placement within the system. Thus, for example, specific environmental influences created either by the location or by adjoining components can be taken into account. Furthermore, specific mechanical and/or electrical influences of certain components on other components can also be considered. Thus, any influence by any component as well as specific influences of a component location on its performance can be taken into account. 
         [0016]    However, many other factors might not been known at the time of the design. Thus, as shown in step  240 , during operation of the system, certain maintenance services and/or repair services will be performed. Each service, whether maintenance or repair, will provide the respective personnel with additional data about the respective task which has been performed. For example, a scheduled maintenance service might require a replacement of a wear and tear part. For example, a valve might require replacement after 10,000 cycles. However, the exchange of this part might show, that the respective part does not show the anticipated wear and replacement was too early. Also, a unscheduled repair service will provide information of, for example, a higher wear and tear of a specific part than anticipated, for example, the valve might show significant damage after only 8,000 cycles. Also other components might show measurable wear and tear. For example, a electrically operated brake needs maintenance after 5,000 activations according to the vendor. However, the service might show only 50% wear and tear. Additional influencing factors might be discovered due to specific types of failures, such as, over heating, additional mechanical stress factors, etc. In particular, due to the specific maintenance/repair service, the respective personnel might be able to deduct certain cross-influential factors which have not been considered during the design phase. This information can now be used by a maintenance tool in step  250  to modify the data base and the maintenance schedule/plan. Thus, an adaptive process takes place during which an optimized customary maintenance schedule/plan can be developed. Furthermore, the respective data base can also be used to generate information about certain cross-influential factors created by the combination of two or more components that are linked in specific ways. Thus, whenever certain combinations of components are used in a new design, these specific cross-influential factors can be taking into account. 
         [0017]    A maintenance service might provide predefined information that can be forwarded automatically or manual to the maintenance tool. For example, the following choices might be available for the service personnel:
       Maintenance service was performed to late (component failure occurred)   Maintenance service was absolutely necessary   Maintenance service was necessary   Maintenance service could have been performed later (optional include time interval)   Maintenance service was unnecessary       
 
         [0023]    The maintenance service might further provide information about an improved maintenance service plan, recommendations to the vendor, and any actual data about the specific component/part. This information can be directly forwarded to the maintenance tool and in addition, this information can be directly stored in the respective component if the component provides for such a storage feature. 
         [0024]    The combination of certain components and their respective effect on the overall system and on specific components can also be generated. For example, using component A in a specific combination with component B might result in 10% increase of wear and tear of part X, whereas a combination of component B and C might decrease a mechanical stress on a specific part Y in component B. Furthermore, environmental factors such as temperature, humidity, pressure, etc. might have positive or negative influence on the performance of certain parts which might not be known or provided by a vendor. Also, a combination of components and environmental conditions might cause certain effects on the overall or specific performance of certain components or parts. All these information can be collected in step  250  during the operation of the system and be used to improve the performance of the system and keep the down time of the system at a minimum. 
         [0025]      FIG. 2  also shows an additional optional step  260  of providing feedback. In this step, the above described specific information can be forwarded to the respective vendors and/or to the designers of the system. This should not be an automatic action without influence of the maintenance personnel to avoid that proprietary information is sent to a vendor. Some of this feedback information can be generated automatically and, for example, be provided to the vendor via email, SMS, in form of a letter, or any other suitable communication form. Thus, the method and tool for optimizing the maintenance service allows not only for improving the respective automation system but also to provide vendors with specific data which can be either used to inform other customers about specific properties of the component or their parts or to improve the respective parts of the components or to improve the recommended maintenance plans for a component. Furthermore, the basic knowledge about specific components can be improved and adapted to allow a better design of new systems. The feedback may comprise, for example, identification and maintenance data of the specific component which can be vendor- or system-specific, maintenance plan recommended by the vendor, application information, and experience of the user/maintenance personnel. 
         [0026]      FIG. 3  shows how operator, designer, and vendor of an automation system can benefit from the optimized maintenance tool and method according to the present invention. In  FIG. 3 , the same system as shown in  FIG. 1  is improved by a maintenance tool  330  as described in  FIG. 2 . To this end, for example, a server  120  is integrated into the control unit  110  and is coupled with the maintenance tool  330 . A network couples all components  130 - 170  with the engineering system  100  and/or the server  120 . Furthermore, each component may comprise a memory unit  130   a ,  140   a ,  150   a ,  160   a , and  170   a  for storing the respective maintenance data developed during operation of the system. In particular components with sub-components, such as, component  140  may comprise an additional memory unit  140   b  which contains the information of memory units  160   a  and  170   a  of sub-components  160  and  170 . The server  120  may forward the acquired data to the maintenance tool  330  which processes these data as described above. Furthermore, the server  120  may forward the same or specifically selected data to the component manufacturer/vendor and the system designer. To this end specific filters can be implemented to provide the respective parties with only suitable data. Furthermore, or alternatively the engineering system can provide the information about the components for example, via Internet, directly to the maintenance tool  330 , the component manufacturer/vendor  310 , and the system designer  320 . Also, certain environmental characteristics of the specific location or specific measurable parameters of a component can be directly measured. Component  150  in  FIG. 3 , for example, is equipped with two sensors  340  and  350  which are coupled with the network to provide the respective data. These sensors may measure, temperature, pressure, stress, etc. 
         [0027]      FIG. 4  shows the generally different influences of the optimized maintenance tool and method on different stages of the development of an automation system. A simplified flow chart as shown in  FIG. 4  shows, for example, a first step  410  in which the product or process is designed. In the following step  420 , the specific mechanical and electrical designs are made. Engineering takes place in the following step  430 . After installation and commissioning in step  440 , the system is operated and maintained in step  450 . This leads to the step  460  of collecting experience as described above in the specific embodiments. The dotted arrows show which steps in this process, in particular for future developments can be influenced by such a method. The acquired experience leads to information and data that might improve the different design phases in step  410 - 430  as well as in the improvement of an existing system, for example, as shown with step  470  indicating modernization and upgrade of an existing system.