Process control system with an alarm analysis system and method for providing statistics on alarms from a process control system, computer program product and computer-readable medium

Abstract

Process control system (1), comprising an alarm analysis system for providing statistics on alarms collected by the process control system (1), comprising an alarm server (4) that receives and stores alarms from one or more processes monitored by the process control system (1), wherein the alarm server (4) comprises an alarm handling service (8) and an alarm analysis service (18), both of which run on the alarm server (4), wherein the alarm handling service (8) is adapted to sort the alarms into a plurality of alarm lists intended for different operators, wherein the alarm analysis service (18) of the alarm analysis system is adapted for at least some of the alarm lists to calculate one or more key figures based on the alarms stored in the alarm server (4), and to recalculate the key figures when a new alarm is received from the alarm server (4), and wherein the alarm analysis service (18) is adapted to automatically generate real-time statistics based on alarms stored in the alarm server (4); wherein the process control system (1) includes at least one human-machine interface (5a-b) for displaying the alarm lists and the alarm analysis system is adapted to display the statistics as a graphical representation (20a-b) on the human-machine interface (5a-b) on the same display screen as a graphical representation (10a-b) of the alarm lists; and wherein the human-machine interface (5a-b) is adapted to display a process representation that illustrates the status of the controlled process, and the alarm analysis system is adapted to display the statistics on the process representation.

Description

AREA OF INVENTION

[0001] The present invention relates to an alarm analysis system that provides statistics on alarms collected by a process control system and includes an alarm server that receives and stores alarms from one or more process sections and is monitored by the control system. The invention also relates to a method for analyzing alarms collected by such a process control system.

[0002] The present invention is useful in conjunction with control systems for any type of industrial process, such as in the pulp and paper industry, the oil and gas industry, the metal industry and the nuclear industry. STATE OF THE ART

[0003] A conventional process control system receives alarms from external devices, such as sensors, PLCs, and control units, that monitor and control the process. The process control system includes an alarm system with an alarm server that compiles the alarms and provides alarm lists for one or more operators. An alarm list contains active alarms and inactive alarms that have not been acknowledged by an operator. For example, an alarm is active when an upper limit is exceeded and becomes inactive when it falls below the upper limit. The alarm lists are displayed in real time on a human-machine interface of the process control system, so the operator is immediately notified of any new alarms.In a large control system, different operators may be responsible for different parts of the process. For example, one operator might be responsible for various process sections of a factory and only be interested in statistics for their own sections. Therefore, it is common practice to sort received alarms into separate alarm lists, and for each operator to be able to view their own alarm list containing alarms from the parts of the process for which they are responsible.

[0004] Sorting alarms into different alarm lists reduces the number of alarms displayed to a given operator. Despite this measure, the number of alarms displayed to an operator can still become extremely high. Consequently, it can be difficult for the operator to assess all alarms and take action to resolve them. The number of alarms can be disproportionately high if the project developers have not carefully selected alarm thresholds but instead opted for default thresholds for most links. A well-known solution to this problem is to use an external alarm management system that analyzes the alarms, provides statistics on them, and generates reports and trends based on the received alarms. The alarm management system calculates a variety of key performance indicators (KPIs) based on the alarms received by the control system.An example of statistics provided by the alarm management system is the output of the ten most frequent alarms, the ten longest-lasting alarms, the number of alarms per unit of time, and the distribution of alarm priorities.

[0005] US Patent 2004 / 0 133 402 A1 discloses an alarm management device comprising: a data collection device for collecting alarm data generated by a device to be managed; a database for storing the collected alarm data; and an alarm statistics device for preparing alarm statistics on the stored alarm data.The alarm statistics device comprises: a weight coefficient provisioning unit to provide one or more weight coefficient types for each alarm; a total weight coefficient calculation unit to multiply these weight coefficients to obtain a total weight coefficient for each alarm; a weighted case count calculation unit to multiply the total weight coefficient by a "1", which represents one case count for generating each alarm and to obtain a weighted case count; and a statistics processing unit to add the weighted case counts for each alarm to prepare statistics for the weighted number of alarm generation cases.

[0006] DE 697 20 963 T2 discloses a process information and maintenance system for the continuous monitoring, visualization, selection, and maintenance of all control loops of a distributed control system, comprising: a distributed control system with at least one computer with a data acquisition device, a storage device, and a display device for acquiring, storing, and displaying data from at least one sensor, and at least one actuator connected thereto. The system includes an automatic control logic device for automatically controlling at least one acquired process value by modifying the settings of the at least one actuator, and a workstation comprising a workstation computer connected to the at least one computer in the distributed control system.wherein the workstation computer comprises: a) a device for monitoring and acquiring the data and settings of each control loop of the distributed control system from the at least one computer, b) a device for processing the information acquired in step a), c) a device for storing the information processed in step b), d) a device for selecting the control loops to be monitored via the stored processed information, and e) a device for displaying the selected control loops so that a user is informed of the unusual behavior of a loop, wherein the monitoring, visualization, selection, and maintenance of the distributed control system are performed on the workstation.

[0007] EP 0 959 398 A1 describes an alarm analysis tool comprising a process controller, an alarm system host computer, and an alarm tool auxiliary computer. The device includes a computer input / output device connected to the console display, enabling an operator to interact with the alarm information. Embodiments include side log displays that show specific alarm information in an organized and informative manner.

[0008] EP 2 053 502 A2 describes an alarm and event monitor in a process control system. An application station runs an event monitor and an event historian. The alarm and event monitor can be configured to perform operations associated with one or more monitoring routines to monitor various aspects and / or areas connected to one or more process controllers and the exemplary enterprise network.

[0009] The purpose of an alarm management system is to reduce the number of unimportant alarms and to enable the selection of the most critical alarms from the large number generated. A problem with current alarm management systems is that they create additional complexity and costs within the process control system. Reports generated from the database do not reflect real-time data, as they provide a snapshot of the data. Furthermore, it is not possible to display trends with real-time updates. It is also difficult to determine which alarms submitted to the database were actually displayed to a specific operator.

[0010] The object of the present invention is to provide an improved alarm management system that reduces the problems mentioned above.

[0011] According to one aspect of the invention, this problem is solved with an alarm analysis system according to claim 1, in which statistics on the alarms stored on the alarm server are automatically generated in real time,

[0012] The statistics are calculated in real time within the control system and are based directly on the alarms stored in the alarm server. This allows an operator to view the resulting statistics directly in the process control system with real-time updates. Data consistency is guaranteed because the data is generated directly from the alarm server of the process control system without any additional storage. Furthermore, the statistics are generated automatically, and the update does not need to be initiated by an operator. The present invention provides a continuous update of the statistics for the alarms received by the control system. The alarm analysis system software is stored and executed on the hardware of the process control system, for example, on the alarm server.

[0013] According to the invention, the alarm analysis system is adapted to calculate one or more key performance indicators (KPIs) based on alarms stored in the alarm server and to recalculate these KPIs upon receipt of a new alarm on the alarm server. Upon receiving an alarm, the KPIs are automatically recalculated and displayed to the operator. Therefore, the operator is always provided with up-to-date statistics that are updated in real time.

[0014] Key performance indicators (KPIs) are generated directly within the process control system. They are calculated in real time and stored within the system. These KPIs facilitate decisions for operators or process engineers to improve the alarm system. Each KPI provides important information to the operator or process engineer in a clear and easily understandable way.

[0015] According to the invention, the alarm server is adapted to sort alarms into a plurality of alarm lists intended for different operators, and the alarm analysis system is adapted for at least some of the alarm lists to calculate one or more key performance indicators (KPIs) based on the alarms in the alarm list. According to this alarm analysis system, KPIs are calculated and displayed for each of the multiple alarm lists. This alarm analysis system facilitates providing each operator with statistics relevant to their part of the monitored process. Since the KPIs are calculated based on the alarms stored in the alarm list, it is not necessary to re-sort the alarms. Furthermore, it is ensured that the displayed statistics are based on the alarms that were actually displayed to the respective operator.It goes without saying that the alarms can be sorted into other alarm lists for which no key figures are calculated.

[0016] According to the invention, the process control system comprises at least one human-machine interface for displaying alarm lists, and the alarm analysis system is adapted to display the statistics on the human-machine interface in real time. This allows an operator to view the alarm list and the statistics on the same human-machine interface. Therefore, it is possible to view the statistics on the same monitor as the other process information. This makes it easier for the operator to analyze the alarm system and initiate potential improvements.

[0017] According to the invention, the human-machine interface is designed to display a process representation that illustrates the state of the control process, and the alarm analysis system is designed to display key performance indicators (KPIs) in the process representation. This aspect makes it even easier for an operator to analyze the alarm system.

[0018] According to one aspect of the invention, the process control system comprises at least one human-machine interface for displaying the alarm lists, and the alarm analysis system is adapted to display the statistics as a graphical representation on the human-machine interface on the same display screen as a graphical representation of the alarm lists.

[0019] According to another aspect of the invention, the problem is solved by a method according to claim 2. Such a method is characterized in that it comprises the automatic generation and display of real-time statistics based on alarms stored on the alarm server.

[0020] According to a further aspect of the invention, the problem is solved by a computer program product that can be loaded directly into the internal memory of a computer or processor and that comprises software code segments for executing the steps of the method according to claim 2 when the program is executed on a computer. The computer program can be made available on a computer-readable medium or via a network.

[0021] According to another aspect of the invention, the problem is solved by a computer-readable medium with a program stored thereon, wherein the program causes the computer to perform the steps of a method according to the attached set of claims when the program is executed on the computer. BRIEF DESCRIPTION OF THE FIGURES

[0022] The invention will now be described in more detail by describing the different embodiments of the invention and with reference to the attached figures. Fig. Figure 1 shows a process control system and an alarm analysis system according to the state of the art. Fig. Figure 2 shows a process control system and an alarm analysis system according to an embodiment of the invention. Fig. Figure 3a shows a flowchart of an example of an alarm handling service. Fig. Figure 3b shows a flowchart of an example of an alarm analysis service. Fig. Figure 4 shows an example of a process diagram that includes key performance indicators displayed on a human-machine interface of the control system. DETAILED DESCRIPTION OF THE PREFERRED EXAMPLES OF THE INVENTION

[0023] Fig. Figure 1 shows an example of an alarm analysis system for providing statistics and a process control system according to the state of the art. The process control system 1 comprises a plurality of alarm collection units 2, which are adapted to receive alarms and events from external devices 3, such as sensors, PLCs, and control units. The control system further comprises an alarm server 4, including hardware for processing the alarms and events, such as a microprocessor, storage media, and input / output units. The control system includes one or more, in this case two, human-machine interfaces 5a-b with display screens for showing information to an operator or operators of the control system.The alarm server 4 includes storage medium 7 for storing alarm lists and an alarm handling service 8 with software for handling the received alarms and events, for example to sort the alarms into different alarm lists, to store the alarm lists and to provide graphical representations of the alarm lists.

[0024] In some control systems, a single alarm list for process control is sufficient. However, for control systems that monitor, for example, an entire factory with various process sections, each monitored by an individual operator, it is more practical to provide one or more alarm lists for each process section. The alarm list for a process section includes alarms originating from that specific process section. The operator then only needs to view the alarm list for their assigned process section. Graphical representations of the alarm lists are transmitted to the human-machine interface and displayed on screens 5a-5b. In the Fig. In the example shown, graphical representations of two alarm lists 10a-b are provided; one alarm list 10a is displayed on the human-machine interface 5a, and the other alarm list 10b is displayed on the human-machine interface 5b.

[0025] Fig. Figure 1 further shows a state-of-the-art alarm analysis system. The alarm analysis system is hosted on an external computer 12, which is located remotely from the control system. It includes a database 13 for storing alarms and an alarm analysis service 14 adapted to analyze the alarms, provide statistics based on the alarms stored in the database, and generate graphical representations of the alarm lists. The alarm management system also includes a human-machine interface with a display screen 16 that shows the graphical representation of the statistics 17. Alarms received by the control system are transmitted to the external database 13. The analysis of the alarms and the calculation of the statistics are initiated manually by a systems engineer.The systems engineer selects which type of statistics should be calculated and displayed after the calculations have been initiated.

[0026] Fig. Figure 2 shows an alarm analysis system according to an embodiment of the present invention. Among the features described in Figure 2 are an alarm analysis system according to an embodiment of the present invention. Fig. Elements corresponding to the elements shown in section 1 are also represented by the same reference symbols in the table. Fig. 2. The alarm server 4 comprises an alarm analysis system 18, which is adapted to calculate statistics such as key performance indicators (KPIs) based on the alarms in the alarm list, in order to provide a graphical representation 20a-b of the statistics and to display them on the human-machine interface 5a-b of the control system, for example, on the same display screen as the graphical representation 10a-b of the alarm lists. According to the invention, the alarm analysis service 18 is part of the alarm server 4 of the process control system 1. An alarm list or alarm lists stored in the storage medium 7 are stored in storage medium 19, which belongs to the alarm analysis service 18. The alarm analysis service 18 is designed to calculate statistics based on the alarms in the alarm lists stored in storage medium 19.

[0027] Each alarm list has a client assigned to specific alarm types. Different alarm lists can be assigned to the same alarm type, meaning the same alarm can be included in more than one alarm list. When an alarm is received by Alarm Processing Service 8, an Assignment Handler sends the alarm to the client or clients to which the alarm is assigned. Alarms from Alarm Processing Service 8 are assigned to Alarm Analysis Service 18. Alarm Analysis Service 18 is equipped with the exact same client as Alarm Processing Service 8; that is, it is assigned the same alarms and will therefore generate the same alarm lists as Alarm Processing Service 8. Alarm Processing Service 8 stores the alarm lists in storage medium 7, and Alarm Analysis Service 18 stores the alarm lists in storage medium 19.The alarm analysis service 18 stores the alarms according to their assignment in the alarm list in the storage medium 19.

[0028] Upon receiving a new alarm from the alarm handling service 8, the alarm analysis service 18 automatically calculates statistics in the form of key figures based on alarms in the alarm list stored in storage medium 19 and automatically generates a graphical representation 20a-b of the key figures. The graphical representation 20a-b of the key figures is displayed on the screen(s) of the human-machine interface(s) 5a-b. The alarm handling service 8 generates a graphical representation 10a-b of the alarm lists and makes them available to the human-machine interface 5ab.

[0029] As in Fig. As shown in Figure 2, the human-machine interface 5a displays a graphical representation 10a of an alarm list and a graphical representation 20a of statistics based on the alarms contained in alarm list 10a. The human-machine interface 5b displays a different alarm list 10b and a graphical representation 20b of statistics provided based on alarms in alarm list 10b. This makes it possible to display different alarm information to different operators responsible for different sections of the process being controlled. The alarm analysis service 18 is provided in software that runs on the alarm server hardware, for example, on the same hardware that runs the alarm handling service 8.

[0030] Fig. Figure 3a shows a flowchart illustrating the main steps of the alarm handling service. Fig. Figure 3b shows a flowchart illustrating the main steps of the alarm analysis service. It is understood that each block of the flowchart can be implemented through computer program instructions.

[0031] As in Fig. As shown in Figure 3a, the alarm handler waits to receive an alarm from one of the alarm collection units 2, Block 22. When an alarm is received from one of the alarm collection units, the alarm is sorted into one or more alarm lists, Block 24. In this embodiment, the sorting is based on subscriptions made by clients to the alarm lists. The alarm is sent to each client that has subscribed to it. The alarm is stored in the alarm list in the storage medium 7. Simultaneously, the alarm is transmitted to the alarm analysis service 18, along with information about which alarm list or lists the alarm belongs to, Block 26. For example, this information includes details about which client or clients have subscribed to the alarm. Subsequently, a graphical representation of the updated alarm list can be transmitted to the human-machine interface 5a-b, Block 28.The list displayed on the human-machine interface can depend on which alarm list the user has selected to view. The alarm handling service then waits to receive the next alarm.

[0032] As in Fig. As shown in Figure 3b, the alarm analysis service waits to receive an alarm from the alarm handling service (Block 30). The new alarm is stored in the alarm list(s) in storage medium 19, which subscribes to the alarm (Block 32). Once a new alarm is received, the alarm analysis service calculates statistics, such as key performance indicators (KPIs), based on the alarms in the alarm list that belong to the newly received alarm (Block 34). Once the statistics are calculated, a graphical representation of the updated statistics, such as the updated KPIs, is transmitted to the human-machine interface (HMI) 5a-b and displayed on the screen (Block 36). The operator can view the alarm list and the statistics in the same view on the HMI. The screen is automatically updated when a new alarm is received, and the statistics can be displayed in real time.

[0033] Preferably, a multiple set of key performance indicators (KPIs) is calculated and displayed. Examples of KPIs include: - the ten most frequent alarms in a specific time period, - the priority distribution for alarms in a specific time period, - Identification of the alarms that were in an alarm state for the longest periods of time, - how long the alarm was active.

[0034] Fig. Figure 4 shows a view of a control system display screen with a process diagram 41 of a process controlled by the control system, and a graphical representation 42 of alarm statistics superimposed on the process diagram. The process diagram also includes information about the status of the controlled process. The statistics show the twenty most frequent alarms. Preferably, the statistics are updated in real time.

[0035] The statistics can be displayed automatically, or the operator / process engineer can open the statistics manually, for example by clicking on an icon.

[0036] For example, in the embodiment described above, the statistics can be calculated based on alarms, but it is also possible to calculate the statistics based on events and event lists.

Claims

[1] Process control system (1) comprising an alarm analysis system for providing statistics on alarms collected by the process control system (1), comprising an alarm server (4) that receives and stores alarms from one or more processes monitored by the process control system (1), wherein the alarm server (4) comprises an alarm handling service (8) and an alarm analysis service (18), both of which run on the alarm server (4), wherein the alarm handling service (8) is adapted to sort the alarms into a plurality of alarm lists intended for different operators, wherein the alarm analysis service (18) of the alarm analysis system is adapted for at least some of the alarm lists to calculate one or more key figures based on the alarms stored in the alarm server (4), and to recalculate the key figures when a new alarm is received from the alarm server (4), and wherein the alarm analysis service (18) is adapted to automatically generate real-time statistics based on alarms stored in the alarm server (4); wherein the process control system (1) includes at least one human-machine interface (5a-b) for displaying the alarm lists and the alarm analysis system is adapted to display the statistics as a graphical representation (20a-b) on the human-machine interface (5a-b) on the same display screen as a graphical representation (10a-b) of the alarm lists; and wherein the human-machine interface (5a-b) is adapted to display a process representation that illustrates the status of the controlled process, and the alarm analysis system is adapted to display the statistics on the process representation. [2] Method for providing statistics on alarms collected by a process control system (1) which are received and stored in an alarm server (4) which receives and stores alarms from one or more processes monitored by the process control system (1), the procedure includes: an automatic generation of one or more key figures and a recalculation of the key figures upon receipt of a new alarm on the alarm server and the sorting of alarms into a plurality of alarm lists intended for different operators, wherein the provision of statistics includes the calculation, for at least some of the alarm lists, of one or more key figures for each alarm list, and wherein the statistics are automatically generated based on the alarms stored on the alarm server (4); wherein the alarm lists are displayed on at least one human-machine interface (5a-b), and wherein the method includes displaying the statistics as a graphical representation (20a-b) on the human-machine interface (5a-b) on the same display screen as a graphical representation (10a-b) of the alarm lists in real time; and wherein The process display (5a-b) is shown on the human-machine interface, illustrating the status of the controlled process, and the procedure includes displaying the statistics on the process display. [3] A computer program product that can be loaded directly into the internal memory of a computer and comprises software for performing the steps of claim 2. [4] Computer-readable medium, with a program stored thereon, wherein the program causes a computer to perform the steps of claim 2 when the program is executed on a computer.

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