Patent Publication Number: US-11385138-B2

Title: Laboratory testing-based valve prognostics

Description:
RELATED APPLICATIONS 
     This application is a divisional application of, and claims the benefit of priority of, U.S. patent application Ser. No. 14/211,157, filed Mar. 14, 2014, which claims the benefit of priority under 35 U.S.C. § 119 of U.S. Provisional Patent Application 61/785,073, filed Mar. 14, 2013, entitled “Laboratory Testing-Based Valve Prognostics,” which applications are hereby incorporated herein by reference in their entireties and for all purposes. 
    
    
     FIELD OF TECHNOLOGY 
     The present disclosure relates to process control devices within process plants and, more specifically, to techniques for performing lifetime prognostics on the process control devices. 
     BACKGROUND 
     Existing process control systems may perform periodic diagnostics on process control devices, such as valves, to determine the operability and performance of such devices. Determining the operability of a process control device may permit better scheduling of maintenance of the process control device, thereby decreasing failure occurrences and down time. This may result in increased efficiency, safety, and revenue. The process control systems may use various sensors and other measurement devices to observe characteristics of a process control device. For example, some existing control systems may use a digital valve controller to measure and collect data from various sensors on a control valve. 
     Among the uses of data collected from control valves, customers desire the data to plan preventative maintenance for their process plants, hoping to avoid unplanned maintenance and loss of production cause by unexpected failures. Customers, for example, will want to know the projected life span of a valve, before requiring maintenance, as well as what repair procedures and replacement options are available and recommended. For the manufacturer, providing a precise life span prediction is challenging because actual process conditions will vary dramatically from customer to customer, or facility to facility, even within a processing plant. Specification sheets may be provided to the customers providing some projection data, and sometimes in response to customer provided design conditions. However, factors such as temperature and pressure often vary dramatically from those provided in the design conditions from the customer and either way, other varying conditions such as fluid state (liquid or vapor) and impurities (solid, liquid, or vapor) are typically not provided in the design conditions, or, as with the other factors, can vary considerably during actual use. 
     Conventionally, service and repair history data from customers would be collected to create Mean Time To Failure (MTTF) and Mean Time Between Failure (MTBF). This MTTF and MTBF data could then be used for predicting life span of a valve. Using this historical data can be limiting, however, because maintenance records may be incomplete or non-existent. Furthermore, customers may not desire to share such information out of a concern that their operating conditions would be disclosed to their competitors. The result is that MTTF and MTBF data, based on historical data, are often incomplete and not sufficiently informative. 
     Another technique for predicting MTTF and MTBF is through the use of laboratory data produced in conditions as closely approximating real life conditions as possible. Pressure and temperature conditions are usually easy to achieve in a well-equipped lab. Fluid properties and contaminations, however, are much more difficult to simulate; although the essential fluid properties typically can be achieved, i.e., oxidizing, non-oxidizing, wet, dry, lubricating and non-lubricating. Occasionally, even a known contamination can be achieved such as with particulates in the fluid stream. Laboratory cycle testing in particular, e.g., at the same temperature, pressure and fluid properties that represent particular valve service applications, can be an effective ersatz for actual field data. This is especially the case for valve components that are subject to normal mechanical wear or fatigue. 
     While laboratory testing is used, for the foregoing and other reasons, conventional testing methods of determining MTTF and MTBF are lacking. The methods are unable to account for the varied conditions and various factors that affect device life span, particularly, those relating to sliding stem valves and rotary valves, where the various components that can wear or fatigue, resulting in valve failure, are many and each with potentially different responses to operating conditions, such as temperature, pressure, fluid, etc. 
     SUMMARY OF THE INVENTION 
     In accordance with an example, a method for developing a projected lifetime profile for a component of a process control device is provided. The method may include receiving an identification of a component capable of experiencing mechanical wear or fatigue, over time, during operation of the process control device, and receiving an operating parameter corresponding to the component. That component performance degrades over time as a result of the changing values of that operating parameter. The method may include receiving previously-recorded performance data of a reference component collected during operation of the reference component under conditions compatible with conditions under which the process control device is to operate. The method may further include developing the projected lifetime profile for the component based on the previously-recorded performance data, wherein the projected lifetime profile indicates a projected lifetime of the component as a function of values of the operating parameter. 
     In accordance with another example, a method for determining a projected remaining lifetime for a component of a process control device is provided. The method may include receiving a projected lifetime profile for the component, where the projected lifetime profile is developed based on previously-recorded performance data collected during operation of a reference component under conditions compatible with conditions under which the process control device is to operate, and wherein the projected lifetime profile indicates a projected lifetime of the component as a function of an operating parameter. The method may include receiving current data on the operating parameter for the component during operation of the process control device. The method further includes analyzing that current data and the projected lifetime profile to determine a projected remaining lifetime for the component. The method may further include determining an operator notification state of the component based the determined projected remaining lifetime. In some examples, notification state data are communicated to remote personnel, such as a process control device operator or maintenance personnel, to schedule maintenance on the component. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a diagram of a process plant configured to receive and coordinate data transfer between many functional areas of the plant; 
         FIG. 2  is a block diagram of an example process control device used in a process control system, where the example process control device is a valve assembly having an embedded integrated diagnostics module; 
         FIG. 3  is a block diagram of another example process control device used in a process control system, where the example process control device is a valve assembly and a remote computer contains an integrated diagnostics module; 
         FIG. 4  illustrates an example of the valve assembly of  FIGS. 2 and 3  showing various valve components that may be profiled; 
         FIG. 5  is a block diagram of an integrated diagnostics module used to profile lifetimes of the valve components of  FIG. 4 ; and 
         FIGS. 6A-6D  are plots of projected lifetime profiles developed by the integrated diagnostics module for each of the valve components identified in  FIG. 3 . 
     
    
    
     DETAILED DESCRIPTION 
     Although the following text sets forth a detailed description of numerous different embodiments, it should be understood that the legal scope of the description is defined by the words of the claims set forth at the end of this patent. The detailed description is to be construed as exemplary only and does not describe every possible embodiment since describing every possible embodiment would be impractical, if not impossible. Numerous alternative embodiments could be implemented, using either current technology or technology developed after the filing date of this patent, which would still fall within the scope of the claims. 
     Referring now to  FIG. 1 , a process plant  10  includes a number of business and other computer systems interconnected with a number of control and maintenance systems by one or more communication networks. 
     The process control system  12  and  14  may be, for example, DeltaVTM controllers sold by Fisher-Rosemount Systems, Inc. of Austin, Tex. or any other desired type of controllers or DCS which My include an operator interface  12 A coupled to a controller  12 B and to input/output (I/O) cards  12 C which, in turn, are coupled to various field devices such as analog and Highway Addressable Remote Transmitter (HART) field devices  15 . The process control system  14  may include one or more operator interfaces  14 A coupled to one or more distributed controllers  14 B via a bus, such as an Ethernet bus. The controllers  14 B are connected via I/O devices to one or more field devices  16 , such as for example, HART or Fieldbus field devices or any other smart or non-smart field devices including, for example, those that use any of the PROFIBUS®, WORLDFIP®, Device-Net®, AS-Interface and CAN protocols. As is known, the field devices  16  may provide analog or digital information to the controllers  14 B related to process variables as well as to other device information. The operator interfaces  14 A may store and execute tools available to the process control operator for controlling the operation of the process including, for example, control optimizers, diagnostic experts, neural networks, tuners, etc. 
     Still further, maintenance systems, such as computers executing an asset management application or any other device monitoring and communication applications may be connected to the process control systems  12  and  14  or to the individual devices therein to perform maintenance and monitoring activities. For example, a maintenance computer  18  may be connected to the controller  12 B and/or to the devices  15  via any desired communication lines or networks (including wireless or handheld device networks) to communicate with and, in some instances, reconfigure or perform other maintenance activities on the devices  15 . Similarly, asset management applications may be installed in and executed by one or more of the user interfaces  14 A associated with the distributed process control system  14  to perform maintenance and monitoring functions, including data collection related to the operating status of the devices  16 . 
     The process plant  10  also includes various rotating equipment  20 , such as turbines, motors, etc. which are connected to a maintenance computer  22  via some permanent or temporary communication link (such as a bus, a wireless communication system or hand held devices which are connected to the equipment  20  to take readings and are then removed). The maintenance computer  22  may store and execute known monitoring and diagnostic applications  23  provided by, for example, CSI 2140 Machinery Health Analyzer from CSI-Computational Systems, Inc. of Knoxville, Tenn. or other any other known applications used to diagnose, monitor and optimize the operating state of the rotating equipment  20 . Maintenance personnel usually use the applications  23  to maintain and oversee the performance of rotating equipment  20  in the plant  10 , to determine problems with the rotating equipment  20  and to determine when and if the rotating equipment  20  must be repaired or replaced. 
     To facilitate communications regarding maintenance of the various equipment (i.e., process control devices), in the illustrated example, a computer system  30  is provided which is communicatively connected to the computers or interfaces associated with the various functional systems within the plant  10 , including the process control functions  12  and  14 , the maintenance functions such as those implemented in the computers  18 ,  14 A,  22  and  26  and the business functions. In particular, the computer system  30  is communicatively connected to the process control system  12  and to the maintenance interface  18  associated with that control system, is connected to the process control and/or maintenance interfaces  14 A of the process control system  14 , and is connected to the rotating equipment maintenance computer  22 , all via a bus  32 . The bus  32  may use any desired or appropriate local area network (LAN) or wide area network (WAN) protocol to provide communications. 
     As illustrated in  FIG. 1 , the computer  30  is also connected via the same or a different network bus  32  to business system computers and maintenance planning computers  35  and  36 , which may execute, for example, enterprise resource planning (ERP), material resource planning (MRP), accounting, production and customer ordering systems, maintenance planning systems or any other desired business applications such as parts, supplies and raw materials ordering applications, production scheduling applications, etc. The computer  30  may also be connected via, for example, the bus  32 , to a plantwide LAN  37 , a corporate WAN  38  as well as to a computer system  40  that enables remote monitoring of or communication with the plant  10  from remote locations. 
     Generally speaking, the computer  30  stores and executes an asset management system  50  that collects data and other information generated by the process control systems  12  and  14 , the maintenance systems  18 ,  22  and  26  and the business systems  35  and  36  as well as information generated by data analysis tools executed in each of these systems. 
     Also, generally speaking, one or more user interface routines  58  can be stored in and executed by one or more of the computers within the plant  10 . For example, the computer  30 , the user interface  14 A, the business system computer  35  or any other computer may run a user interface routine  58 . Each user interface routine  58  can receive or subscribe to information from the asset management system  50  and either the same or different sets of data may be sent to each of the user interface routines  58 . Any one of the user interface routines  58  can provide different types of information using different screens to different users. For example, one of the user interface routines  58  may provide a screen or set of screens to a control operator or to a business person to enable that person to set constraints or to choose optimization variables for use in a standard control routine or in a control optimizer routine. The user interface routine  58  may provide a control guidance tool that enables a user to view the indices created by the index generation software  51  in some coordinated manner. This operator guidance tool may also enable the operator or any other person to obtain information about the states of devices, control loops, units, etc. and to easily see the information related to the problems with these entities, as that information has been detected by other software within the process plant  10 . The user interface routine  58  may also provide performance monitoring screens using performance monitoring data provided by or generated by the tools  23  and  27 , the maintenance programs such as an asset management application or any other maintenance programs, or as generated by the models in conjunction with the asset management system  50 . Of course, the user interface routine  58  may provide any user access to and enable the user to change preferences or other variables used in any or all functional areas of the plant  10 . 
     The plant  10  illustrates various process control devices (e.g., devices  14 ,  15 ,  16 ,  20 , and  25 ), that may degrade in performance over time and require maintenance. Certain process control devices, such as a control valves or other devices, are used to modulate or control fluid flow within the process control system, under the control of process control systems  12  and  14 . (Fluids, in this case, may include gaseous fluids such as compressed nitrogen gas, etc.) These are provided by way of example, as it should be understood by one of ordinary skill in the art that although the example embodiments described herein are based upon pneumatic control valves, other process control devices such as pumps, electrically-actuated valves, and dampers will also affect process plant operation and may be included in the techniques described herein. 
     In general, process control devices, such as control valve assemblies, may be positioned in conduits or pipes to control fluid flow by altering the position of a moveable element, such as a valve plug within the control valve, using an attached actuator and positioner. The adjustments to the control element may be used to influence some process condition to maintain a selected flow rate, a pressure, a fluid level or a temperature. 
     A control valve assembly is typically operated from a regulated source of pneumatic fluid pressure, such as air from a plant compressor. This fluid pressure is introduced into the actuator (such as a spring and diaphragm actuator for sliding stem valves or a piston actuator for rotary valves) through a positioner or valve control instrument which controls the fluid pressure in response to a signal received from the process control system. The magnitude of the fluid pressure in the actuator determines the movement and position of the spring and diaphragm or piston within the actuator, thereby controlling the position of a valve stem coupled to the moveable element of the control valve. For example, in the spring and diaphragm actuator, the diaphragm must work against a bias spring, to position the moveable element (i.e., valve plug) within a valve passageway between the inlet and the outlet of the control valve to modify flow within the process control system. The actuator may be designed so that increasing fluid pressure in the pressure chamber either increases the extent of the moveable element opening or decreases it (e.g., direct acting or reverse acting), the former situation being assumed herein. While these descriptions may be applicable to a sliding stem valve, corresponding components and operations would apply to rotary valves. 
       FIG. 2  illustrates a general control valve assembly  100  that may be used in the process control system  12  or  14 . A control valve  102  may have a moveable element, such as valve stem and valve plug (not shown), that is selectively positioned by an actuator  104  being controlled by a positioner to modify process flow. It is understood by one of ordinary skill in the art that an indication of the position of the valve plug moveable element is provided through a position sensor  106 , which may be integrated into the valve position controller  108  or may be a standalone positioner transmitter. The control valve  102  creates a variable orifice within the flow path of the process control system to control the flow of process materials in the process control system. The process control system may generally use transmitter  110  to detect a process variable to characterize the process. The process variable may be transmitted back to a process device controller  112  directing the operation of the process plant to control the process. 
     A valve controller  114  includes the valve position controller  108 , the position sensor  106  and may also include an actuator control signal generator  116 , that may include, for example, an electro-pneumatic stage (not shown) that is controlled by a microcomputer provided therein, that generates an output signal from the valve position controller  108  to drive the actuator  104 . It should be appreciated by one of ordinary skill in the art that the actuator may be an electric actuator (not shown) and the actuator control signal generator may provide an electric control signal to control or modify the position of the electric actuator. The actuator control signal generator  116  converts the output signal from valve position controller  108  to the corresponding control value to be established in the actuator  104 . The position sensor  106  may monitor actuator  104  for position input information (via the actuator stem position) or control valve  102  (via the valve stem), shown as a dotted line. 
     In operation, a user interacts with the control valve  102  and process  118  at a user process control interface  120  that provides commands to the process controller  112  responsible for the control of the entire process, where the process controller  112  is in communication with other control devices (not shown) used in the plant for process control. The process controller  112  may translate the input commands supplied by the user at interface  120  into setpoint signal commands. The setpoint signal commands may then be sent to valve controller  114 , and specifically to the valve position controller  108 . The valve position controller  108  may have therein the microcomputer described above. The microcomputer may be programmed to follow an algorithm for controlling the control valve  102  in response to received setpoint signal commands and directing the actuator control signal generator  116  to generate a corresponding control signal in the actuator  104  for positioning the control valve  102 . 
     In the system of  FIG. 2 , increases in magnitudes of the setpoint commands may cause corresponding increases in the pneumatic pressure provided by the actuator control signal generator  116  in the valve controller  114 , thereby effecting, via the actuator  104 , corresponding increases in the opening controlled by the moveable element of the control valve  102 . The resulting position of the moveable element may have an effect on the process and, accordingly, on the process variable monitored and detected by the process variable transmitter  110 . The process variable transmitter  110  transmits a representative signal of the process variable back to process controller  112 . One of ordinary skill in the art will understand that the process controller  112  uses the representative signal as an indication of the status of the process for feedback to control the system. 
     As discussed above, the process controller  112  may be in communication with other control devices used in the plant for process control. The process controller  112  may also include or may be connected to a computer having general computing elements such as a processor or processing apparatus, a memory, an input device and a display device (e.g., monitor). The processor may be connected to the memory, the display device, and the input device, as known by those skilled in the art. Also, the computer may include a network interface for connecting between a network and the computer to provide communication therebetween. In one embodiment, the computer may form a portion of the process controller, such as in a digital process controller. In another embodiment, the user process control interface may represent the computer. Alternatively, the computer may be connected on a network to the process controller but be physically remote from the process controller. 
     The valve controller  114  also includes or, alternatively, receives information from, an operating conditions sensor  122  that monitors one or more operating conditions for the valve  102  and/or the valve actuator  104  and/or one or more environmental conditions under which the valve  102  is operating. The operating conditions sensor  122  may be any sensor or transmitter that detects or otherwise monitors an operating condition at or near the valve  102  or the valve actuator  104 . For example, the operating conditions sensor may monitor a temperature of a fluid flowing through the valve  102 , a temperature of fluid operating the valve actuator  104 , a temperature of fluid moving through the position controller  108 , an ambient air temperature of the valve  102 , the valve actuator  104 , or the valve position controller  108 , a pH level of any of the fluids mentioned above, a pressure (upstream or downstream) of any of the fluids above, a salinity or viscosity of any of the fluids above, etc. The operating condition sensor  122  is coupled to provide sensed operating condition data to the valve position controller  108  for affecting control of the valve  102  and to an integrated diagnostics module  124 . In some embodiments, operating condition sensor  122  transmits data to a data historian or other centralized data collection element, and the diagnostics module  124  retrieves the operating condition data therefrom. 
     Multiple operating conditions sensors  122  and/or multiple position sensors  106  may be disposed throughout the system shown in  FIG. 2  to detect and/or measure characteristics of the control device and system and may provide this characteristic information or data to the computer or process device controller  112  for display on the display device element. In one embodiment, the sensor data from both sensors  106  and  122  are collected by the integrated diagnostics module  124 , which may include a computer processor and memory. In some examples, a diagnostic monitor  126  coupled to the module  124  represents a computer display device that displays the sensor data or data output by the module  124 . The input device element of the computer may be, for example, a keyboard, a touchpad, mouse, trackball, a lightpen, microphone (e.g., for voice command inputs), etc. Note also that various embodiments of the claimed method and system described below may be implemented as a set of instructions in the processor of the computer for execution, as known by those skilled in the art. 
     The integrated diagnostics module  124  develops and implements prognostic algorithms for process control devices to predict the end of usable life for these devices and/or various components thereof. Example process control devices exemplified herein are valve assemblies. However, more broadly, an integrated diagnostics module may be used with any process control device that experiences mechanical wear or fatigue over time, including devices that modulate fluid flow in a process, such as valves, pumps, and dampers, and may be implemented to predict the end of useable life for the components of each and any of these devices. 
     The integrated diagnostics module  124  assembles prognostics algorithms for components that form the process control device and from which usable remaining lifetime (e.g., remaining cycle life time, projected maintenance date) data may be determined. As discussed further below, the integrated diagnostics module  124  may derive these algorithms from documented average or minimum service life of multiple process control devices of the same type and construction materials, as used in a given application, from laboratory data collected in a manner that most nearly approximates field service conditions (e.g., operating environment), and/or from historical data of identical or similar devices, or parts of devices, in the plant or environment in which the device or part is installed. Such algorithms, therefore, may take into account those components that normally fail by mechanical wear or fatigue and which can be characterized as having a fixed or average lifetime when new. For example, when projecting cycle life, the integrated diagnostics module  124  may decrement a fixed or average cycle life, by each cycle experienced during operation. Such a decrement would occur automatically, for example, in response to an automatic sensor at the process control device or from operator input. As another example, the integrated diagnostics module  124  may decrement a fixed or average movement life (e.g., of a seal around a valve stem) by the cumulative movement of a part (e.g., the valve stem) as sensed by the position sensor  104  in the valve actuator  104  or in the valve  102 , as controlled by the actuator control signal generator  116 , as controlled by the valve position controller  108 , or even as controlled by the process controller  112 . 
     In some examples, the remaining lifetime is determined based at least in part on data from sensors (e.g., sensors  106  and  122 ) measuring normal operating conditions, where the data are collected at periodic determined time intervals, or on a continuous basis, or in response to some triggering event. In some examples, the remaining lifetime is determined based at least in part on information from the process controller  112 , the valve position controller  108 , and/or the valve actuator  104 . For instance, the remaining lifetime may be determining, in some embodiments, according to the one or more operating conditions as sensed by the sensor  122  and according to the number of open/close cycles as instructed by the process controller  112  (as opposed to receiving the number of open/close cycles from the actuator  104  or the position sensor  106 ). 
     The integrated diagnostics module  124  is able to determine remaining lifetime for each replaceable component of the process control device (e.g., plugs, seals, bushings, bearings, etc.), as well as for the process control device as a whole. In either case, the remaining lifetime may be based solely on characteristics of the particular process control device or components in question or based on characteristics measured from other processing plant devices or data. The latter may include other devices operating in coordination with the device in question, as well general operating conditions of the processing plant. The particular remaining lifetime data may be stored in a computer readable memory device, for example, by a smart positioner device in a valve configuration, such as within the valve controller  114  of  FIG. 2 . 
     The integrated diagnostics module  124  is able to communicate with a remote computer, such as a system controller  12  or  14 , through a communication interface  128  that may be a wired or wireless communication interface, which remote computer may, in some instances, take some process control action (e.g., adjusting the use of a valve—for example, the speed or frequency of actuation—to prolong the life of a component of the valve, switching to a redundant device/flow path, etc) based on data received from the integrated diagnostics module  124 . 
     As illustrated in  FIG. 2 , and as described above, the integrated diagnostics module  124  may receive a variety of inputs in various implementations. Among the inputs are inputs from one or more operating conditions sensor(s)  122 , one or more position sensor(s)  106 , one or more process variable transmitter(s)  110 , the process controller  112 , and the communication interface  128 . Each of the operating conditions sensors  122  may sense a different parameter (e.g., temperature, pressure, viscosity, flow rate, etc.), or may sense the same parameter as another sensor, but at a different location (e.g., upstream and downstream pressure, temperature of fluid flowing through the valve  102  and temperature of fluid controlling the actuator  104 , etc.). Each of the one or more position sensors  106  may sense a position of a different element (e.g., the position of a valve stem and the position of an actuator stem). The integrated diagnostics module  124  may also include (e.g., as stored in a memory device) or retrieve/receive (e.g., via the communication interface  128 ) data and/or algorithms to use in determining the remaining useful life of the device or the components of the device. 
     In the example of  FIG. 2  the integrated diagnostics module  124  is embedded within the valve assembly  100 . For example, the module  124  may be implemented by an on-board processor (of the controller  114 ), or by instructions being executed by such a processor, in a smart process control device.  FIG. 3  illustrates another example configuration, with a valve assembly  100 ′, having similar features to that of valve assembly  100 , except that an integrated diagnostics module  150  is contained within a remote computer system  152 , such as a multiplexed host computer, a DCS system, a plant asset management system (such as the asset management system  50 ), or any combination of these. The communication interface  128 ′ packages the operating conditions data from sensor(s)  122 ′ and the sensor(s)  106 ′ and transmits them to the remote computer system  152  for profiling by the integrated diagnostics module  150 . 
       FIG. 4  is an example process control device in the form of a valve assembly  200  made up of various components, which each have potentially different lifetime profiles that will be determined by an integrated diagnostics module (e.g., the integrated diagnostics module  124 ). In the illustrated examples these lifetime profiles are cycle lifetime profiles, because they depend on the number of operating cycles the valve experiences (e.g., the number of experienced fully open/close operations of the number of experienced partially open/close operations). In the illustrated example, the valve assembly  200  is formed of a series of components that may be profiled using lab testing data or previously collected historical data of actual in-use valve assemblies. In this way, lifetime profiles may be developed from real world data reflecting the particular conditions experienced in a processing plant installation. The particular components illustrated include a diaphragm header component  202  and a shaft receptacle  204  connected to a seal component  206  and engaged with a valve body  208  through packing gland (bushings, or bearings) component  210 . 
     A valve controller  212  corresponding to the valve controller  114 , in whole or in part, controls valve actuation and position. An integrated diagnostics module within the valve controller  212  collects various operating data and profile data to determine a cycle lifetime profile for each of these various components, using a prognostic algorithm. In some examples, such as  FIG. 2 , the prognostic algorithm is applied by an on-board processor within a dedicated positioner instrument, within a valve controller. In some examples, such as  FIG. 3 , the prognostic algorithm is applied by a multiplexed host computer in communication with the valve controller  212 , such as the computer systems  30 ,  35  or  36 . In yet other examples, a distributed process control (DCS) system or a plant asset management system, such as the asset management system  50 , in communication with the controller  212  may be used. In yet other examples, a combination of these analysis configurations may be used, which may be beneficial when component cycle life from numerous different sources is used. 
       FIG. 5  illustrates an example integrated diagnostics module  400  (corresponding, for example, to the integrated diagnostics module  124 ) as may be contained within the valve controller  312  or the remote computer system  152 . The module  400  is configured to have access to a device descriptor  402  that identifies the particular process control device under analysis (e.g., valve assembly, pump assembly, damper, etc.). The device descriptor  402  may be embedded within the process control device either by the manufacturer or by a customer and may be a file, stored in a memory device, that is fixed or re-writeable, in various embodiments. In some examples, the device descriptor  402  is a re-writeable or otherwise configurable part of the user process control interface  120 , so as to facilitate manual identification or selection of the particular process control device to be profiled. In any event, the device descriptor  402  may be stored locally at the process control device or on a remote computer system, such as the systems  12 ,  14 ,  30 ,  35 , or  36 . 
     The device descriptor  402  accesses a list file  404  that identifies the components forming the process control device and that have profilable lifetime, and may identify for each component any data needed to create a lifetime profile for the component, as described below. In the example of  FIG. 4 , the list file  404  identifies the diaphragm header component  302 , the shaft receptacle  304 , the seal component  306 , and the packing gland component  310  as profilable components of the valve assembly  300 . 
     In some embodiments, the components listed in the list file  404  depend upon the type of process control device. For a sliding stem valve assembly, for example, a list file  404  may identify any one or more of the following components that will experience mechanical wear or fatigue during operation: actuator diaphragm or piston and rod seals, actuator guide bushings or bearings, valve packing, valve stem, stem or plug guide bushings or bearings, valve plug balance seals, valve plug, valve cage, bellows seals, and/or actuator springs. For a rotary valve assembly, the list file  404  may identify actuator diaphragm or piston and rod seals, actuator guide bushings or bearings, actuator rod end bearings, valve shafts, valve bearings or bushings, seals, disks, balls, segmented balls or plugs, and/or actuator springs. 
     In other embodiments, the list file  404  may include all of the components for a particular line of devices of a particular type, or all of the components for a manufacturers entire product line. In these embodiments, the integrated diagnostics module  400  may retrieve from the list file  404  only data relating to the devices identified by the device descriptor  402 . For example, the device descriptor  402  may identify (e.g., by being programmed/configured by an operator or technician) a particular type of valve actuated by a particular type of actuator. The module  400  may then retrieve from the device descriptor  402  data related to components that are associated with the particular actuator and valve types. In some embodiments, the list file  404  may be stored remotely, such as on a server accessible via a communication network such as a LAN (e.g., where the list file  404  is stored on a plant server) or the Internet (e.g., where the list file  404  is stored on a device manufacturer server). 
     The list file  404  may also identify fatiguing accessories mounted to a valve assembly or valve positioner, such as volume boosters, solenoids, trip valves, limit switches, position transmitters, instrument supply pressure regulators, and pneumatic tubing. 
     While a single list file  404  is shown in  FIG. 5 , in other examples, multiple list files may be used, for example, to allow standard valve components to be listed in one list file and fatigue accessories listed in another list file. 
     Where multiple components are stored in the device descriptor  402 , different list files  404  for each part may be accessed under instruction from the integrated diagnostics module  400 . 
     The list files  404  may be initiated and updated by a device manufacturer or customer, from operator input. For example a GUI interface may be provided (by interface  120 ) to an operator to allow for selecting pre-existing stored, component entries, as well as for adding and/or deleting component entries. Formation of the list file  404 , therefore, may be performed prior to operation of the process control device. The list file  404  may be updated to include additional components added during operation of the part assembly. Such updating may occur through manual entry by an operator or automatically, for example, for systems in which as accessories are added to a part assembly those accessories are automatically detected by the part controller. 
     In addition to identifying components, the list file  404  may identify, for each of the listed components, an operating parameter that affects the mechanical wear or fatigue of that component during operation of the device. Because the lifetime of each component may be affected by different operating conditions, in some examples, the list file  404  identifies the different operating parameters that are to be accessed by the integrated diagnostics module  400  in developing a component lifetime profile. For example, a valve positioner may fatigue in response to numerous parameters, such as, current to pressure ratio (I/P) experienced by the valve nozzle/flapper, the piezo crystal, or the moving solenoid component. Additional parameters include pressure on a pressure relay, the position of linkages in a valve, the position of various feedback devices, whether such feedback is from a potentiometer, encoder or resolver device. Generally, these operating parameters identify the metrics that are to be sensed and evaluated using a prognostic algorithm to determine a lifetime profile for a component and for the process control device overall. 
     As discussed further below, the integrated diagnostics module  400  may also access stored historical data  406  having previously obtained operating data, maintenance data, mean time to failure, or other data on the device and its components. 
     In the illustrated example, the integrated diagnostics module  400  also accesses lab testing data  407  for the process control device and corresponding components listed in the list file  404 . In other examples, only one of the lab testing data  407  or the historical data  406  is accessed by the module  400 . 
     In the configuration of  FIG. 2  the historical data  406  and the lab test data  407  may be stored locally or accessed remotely through the communication interface  128 . In the configuration of  FIG. 3  the historical data  406  and lab test data  407  may be stored at the remote computer system  152 , e.g., accessible by the computer system  12 ,  14 ,  30 ,  35 , and/or  36 . 
     To diagnose operations of a process control device and develop lifetime profiles, the integrated diagnostics module  400  includes a profiler  408  that collects and stores historical data  406  and lab testing data  407  for at least some of the components listed in the list file  404 . From this data the profiler  408  determines a lifetime profile for each of the identified components and based on the identified corresponding operating parameter(s) associated with that component. The profiler  408  may store previously developed lifetime profiles or may construct them. 
     The determined lifetime profiles are stored in a plurality of different profiles  410 , as illustrated. Example profiles are illustrated in  FIGS. 6A-6D . 
       FIG. 6A  is a lifetime profile developed by the profiler  408 , for the diaphragm component  302 , indicating the lifetime (in hours) of a diaphragm&#39;s oxidation level as a function of temperature and showing a linear downward sloping profile.  FIG. 6B  illustrates a cycle lifetime profile for the packing gland component  310 , indicating the amount of leakage (measured in parts per million) as a function of operation cycles for the component. The cycle lifetime profile includes profile data for at least four different packing gland components, collected from the historical data  406  and/or the lab testing data  407 . 
     When the profiler  408  is provided with multiple data sets, the profile  408  may average the data to determine a mean time to failure, i.e., where the data sets correspond to the same operating parameters. In some examples, the stored data may include historical or lab testing data taken at different operating parameters (e.g., one data set collected showing actual lifetime as a function of pressure another taken showing actual lifetime as a function of temperature). In such cases, the profiler  408  may develop profiles for a component at each of the different operating parameters. 
       FIG. 6C  is a cycle lifetime profile developed for the seal component  306 , indicating the amount of leakage (in ppm) as a function of the number of operating cycles.  FIG. 6D  is a cycle lifetime profile for the shaft component  304 , indicating the percentage failure as a function of the number of operating cycle. While four cycle life profiles are shown, for example purposes, it will be appreciated that any number of cycle life profiles may be stored in the profiler  408  and used by the integrated diagnostics module  400 . 
     In some examples, the profiler  408  is pre-populated with lifetime profiles for components identified in the list file  404 , for example, where the components have been previously profiled, at similar operating conditions. In either case, the profiler  408  is able to update the lifetime profiles based on elapsed time, the number of cycles, or other parameters. For example, for a valve assembly, the profiler  408  may receive a cycle count from a valve positioner or valve state counter  414 . The profiler  408  may receive a temperature value from a temperature sensor (not shown). The profiler  408  may receive position data for the valve from a position sensor. The profiler  408  is able to adjust the lifetime profiles for the components and for the overall valve assembly, based on these parameters. 
     The integrated diagnostics module  400  collects sensor data (e.g., from sensors  106  and  122 ) and stores operating conditions for the process control device in an operational data module  410 . The operating conditions may be real time sensed data corresponding to the operating parameters identified in the list file  404 . As discussed above, for a valve assembly, the sensed data may include any parameter that will affect the mechanical wear or fatigue of the listed components or the valve assembly as a whole, including current to pressure (I/P) experienced by the valve nozzle/flapper, the piezo crystal, or the moving solenoid component, pressure, component temperature, ambient temperature, fluid rate, leakage, oxidation level, the position of linkages in a valve, and the position of various feedback devices. 
     The operating data from the module  410  are provided, along with the lifetime profiles from the profiler  408 , to a remaining lifetime analyzer  412  that analyzes current operating data against the corresponding profiles, for the components, to determine a projected remaining lifetime each component and/or for the entire process control device. For the latter, the analyzer  412  applies a multifactorial analysis algorithm to the received data, to determine the projected lifetime, based on the projected life times of each of components. The projected remaining lifetime values may be cycle lifetime values, when indicated as a function of remaining operating cycles for a valve assembly, for example. While in other examples, the projected remaining lifetime values may be measured or indicated in a counter time or projected failure date. For example, the lifetime analyzer  412  may receive the cycle count value from the counter  414  which it then compares to the profiles from the profiler  408  to determine a projected remaining cycle lifetime. 
     The analyzer  412  may include a confidence determination that assesses whether enough operational data and profiles have been provided to it to make a sufficiently accurate determination of projected cycle life for the process control device. A warning indication may be provided if insufficient sensor data are collected and a remaining projected lifetime cannot be determined for a given valve component. 
     The analyzer  412  provides the projected cycle life time determination to a decision module  418  that determines a notification state for the determination. In an example, the notification state has one of three conditions: (i) NORMAL, indicating no required maintenance; (ii) MAINTENANCE, indicating that maintenance or replacement will be needed at the next scheduled service; or (iii) ALERT, indicating that maintenance or replacement is needed before the next scheduled service. An alert mechanism may be provided on the process control device to indicate the notification state, e.g., with color coded lights or a display. The decision module  418  is coupled to a communication interface  420  (which may be the communication interfaces  128  or  128 ′) for communicating the notification state and projected lifetime determination to a remote computer or operator, such as the remote computer systems  12 ,  14 ,  30 ,  35 , and/or  36 , shown in  FIG. 1 . In addition to providing a local indication of notification state, the communication interface  420  may be a wired or wireless communication interface providing of the indication of the notification state to a host computer, DCS, remote computer, or the like, which, in at least some embodiments, causes a controller to modify the operation of the process plant according to the notification state, for example by decreasing the frequency or speed of actuation, or by switching to a redundant flow path. 
     In this way, the present techniques may provide a warning message to a control room operator, maintenance department or reliability engineering department, where the warning message quantifies the prognosticated remaining time to failure of the component. In some examples, the warnings may be set far enough in advance that they appear during a scheduled maintenance outage occurring before the projected failure time. This would give personnel a chance to plan for service or replacement of the component before the expected failure. The warning messages may include repair data such as recommend spare parts or recommended service actions. The warning messages may be provided to a remote computer system to facilitate manual repair ordering or to enable automatic order of replacement parts from a component manufacturer. The warning message may be provided to business system computers and maintenance planning computers  35  and  36 , which may not only facilitate ordering or replacement parts, as described, but also scheduling such replacement, e.g., during an already scheduled maintenance outage or during a future maintenance outage. 
     In some examples, the timing of the warning message may be set by the operator of the process control device to be longer or shorter than previously set depending upon the assessed condition of the process control device and the impending service projection. For example, the integrated diagnostics module  400  may be configured to provide more frequent warning messages as the projected failure point nears. The timing of the warning messages may also be controlled after the initially warning message has been sent. 
     As a process control device&#39;s performance deteriorates, and more specifically, as the performance of the various components deteriorates, the projected cycle life time data, as well as the eventual actual cycle life time data, are stored in the historical data  406 . From here data such as the MTTF and MTBF for components may be stored for later reference by the integrated diagnostics module  400  or a module for another device, thereby improving the accuracy of future cycle lifetime projections. In some examples, such historical data may be shared with manufactures, through dedicated wired or wireless communications, with the component owner&#39;s consent. For example, such data may be provided by granting access to a shared database, website or wireless network, storing a copy of the historical data  406 . Providing this data allows for eventually replacing lab data with data developed using more-reliable algorithms at the manufacturer end. 
     The prognostic capabilities of the system herein can be customized, based on field experience for a specific application. As with the profiler  408 , the criteria of the lifetime analyzer  412  and decision module  418  can be set based on numerous parameters such as elapsed time, valve travel, cycles, temperature, etc. In this way diagnostic capabilities may be based on field experience in prior installations and data collected by the device controller. 
     In various embodiments, a module may be implemented in hardware or software. For example, a module implemented in hardware may comprise dedicated circuitry or logic that is permanently configured (e.g., as a special-purpose processor, such as a field programmable gate array (FPGA) or an application-specific integrated circuit (ASIC)) to perform certain operations. A module implemented in software may comprise programmable logic or circuitry (e.g., as encompassed within a general-purpose processor or other programmable processor) that is temporarily configured by software to perform certain operations. It will be appreciated that the decision to implement a module in hardware, in dedicated and permanently configured circuitry, or in software, in temporarily configured circuitry (e.g., configured by software), may be driven by cost and time considerations. 
     Accordingly, the term “hardware module” should be understood to encompass a tangible entity, be that an entity that is physically constructed, permanently configured (e.g., hardwired), or temporarily configured (e.g., programmed) to operate in a certain manner or to perform certain operations described herein. As used herein, “hardware-implemented module” refers to a hardware module. Considering embodiments in which hardware modules are temporarily configured (e.g., programmed), each of the hardware modules need not be configured or instantiated at any one instance in time. For example, where the hardware modules comprise a general-purpose processor configured using software, the general-purpose processor may be configured as respective different hardware modules at different times. Software may accordingly configure a processor, for example, to constitute a particular hardware module at one instance of time and to constitute a different hardware module at a different instance of time. 
     Hardware modules can provide information to, and receive information from, other hardware modules. Accordingly, the described hardware modules may be regarded as being communicatively coupled. Where multiple of such hardware modules exist contemporaneously, communications may be achieved through signal transmission (e.g., over appropriate circuits and buses) that connects the hardware modules. In embodiments in which multiple hardware modules are configured or instantiated at different times, communications between such hardware modules may be achieved, for example, through the storage and retrieval of information in memory structures to which the multiple hardware modules have access. For example, one hardware module may perform an operation and store the output of that operation in a memory device to which it is communicatively coupled. A further hardware module may then, at a later time, access the memory device to retrieve and process the stored output. Hardware modules may also initiate communications with input or output devices, and can operate on a resource (e.g., a collection of information). 
     The various operations of example methods described herein may be performed, at least partially, by one or more processors that are temporarily configured (e.g., by software) or permanently configured to perform the relevant operations. Whether temporarily or permanently configured, such processors may constitute processor-implemented modules that operate to perform one or more operations or functions. The modules referred to herein may, in some example embodiments, comprise processor-implemented modules. 
     Similarly, the methods or routines described herein may be at least partially processor-implemented. For example, at least some of the operations of a method may be performed by one or processors or processor-implemented hardware modules. The performance of certain of the operations may be distributed among the one or more processors, not only residing within a single machine, but also deployed across a number of machines. In some example embodiments, the processor or processors may be located in a single location (e.g., within a home environment, an office environment or as a server farm), while in other embodiments the processors may be distributed across a number of locations. 
     Still further, the figures depict preferred embodiments of a map editor system for purposes of illustration only. One skilled in the art will readily recognize from the following discussion that alternative embodiments of the structures and methods illustrated herein may be employed without departing from the principles described herein. 
     Upon reading this disclosure, those of skill in the art will appreciate still additional alternative structural and functional designs for a system and a process for identifying terminal road segments through the disclosed principles herein. Thus, while particular embodiments and applications have been illustrated and described, it is to be understood that the disclosed embodiments are not limited to the precise construction and components disclosed herein. Various modifications, changes and variations, which will be apparent to those skilled in the art, may be made in the arrangement, operation and details of the method and apparatus disclosed herein without departing from the spirit and scope defined in the appended claims.