Process and device for evaluating the performance of a process control system
View Patent ↗A preferred process for evaluating the performance of a process control system comprises generating a first set of data comprising a plurality of measurements of a first parameter controlled by the process control system and generating a second set of data comprising a plurality of measurements of a second parameter controlled by the process control system. A preferred process also comprises calculating a first statistical index from the first set of data using a statistical process control method, calculating a second statistical index from the second set of data using the statistical process control method, and combining the first and second statistical indices to produce a performance index representative of the performance of the process control system at controlling the first and second parameters.
1. A process for evaluating the performance of a system, comprising:
sampling data representative of a first and a second parameter controlled by the system;
calculating a first and a second statistical index for the respective first and second parameters;
scaling the first and second statistical indices based on predetermined characteristics of the first and second parameters; and
combining the first and second statistical indices.
2. The process of claim 1 , wherein scaling the first and second statistical indices based on predetermined characteristics of the first and second parameters comprises scaling the first and second statistical indices on a linear basis.
3. The process of claim 1 , wherein scaling the first and second statistical indices based on predetermined characteristics of the first and second parameters comprises scaling the first and second statistical indices based on a relative economic impact of the first and second parameters.
4. The process of claim 1 , wherein scaling the first and second statistical indices based on predetermined characteristics of the first and second parameters comprises scaling the first and second statistical indices based on a relative magnitude of the first and second parameters.
5. The process of claim 1 , wherein scaling the first and second statistical indices based on predetermined characteristics of the first and second parameters comprises scaling the first and second statistical indices on a non-linear basis.
6. The process of claim 5 , wherein scaling the first and second statistical indices on a non-linear basis comprises squaring each of the first and second indices.
7. The process of claim 1 , wherein calculating a first and a second statistical index for the respective first and second parameters comprises calculating the first and second statistical indices using a statistical process control method.
8. The process of claim 7 , wherein the statistical process control method is a Shewhart statistical process control method.
9. The process of claim 7 , wherein calculating the first and second statistical indices using a statistical process control method comprises calculating a range and an arithmetic mean of a first sample of the data representative of the first process operating parameter and a second sample of the data representative of the second process operating parameter.
10. The process of claim 1 , wherein combining the first and second statistical indices comprises combining the first and second statistical indices using a square-root sum-of-squares technique.
11. The process of claim 1 , wherein sampling data representative of a first and a second parameter controlled by the system comprises sampling the data representative of the first parameter a predetermined number of times over a predetermined interval and simultaneously sampling the data representative of the second parameter the predetermined number of times over the predetermined interval.
12. The process of claim 11 , wherein the predetermined number of times is six and the predetermined interval is approximately ten seconds.
13. The process of claim 1 , further comprising sampling and storing data representative of an operating condition of an automated system controlled by the system.
14. A device for evaluating the performance of a system, comprising an input/output interface for communicating with the system, and a central processing unit electrically coupled to the input/output interface and comprising a processor electrically coupled to the input/output interface, a memory-storage device electrically coupled to the processor, a power supply electrically coupled to the processor and the memory-storage device, and a set of computer-executable instructions stored on the memory-storage device for:
sampling data representative of a first and a second parameter controlled by the system;
calculating a first and a second statistical index for the respective first and second parameters;
scaling the first and second statistical indices based on predetermined characteristics of the first and second parameters; and
combining the first and second statistical indices.
15. The device of claim 14 , further comprising a display screen and a keypad electrically coupled to the input/output interface.
16. The device of claim 14 , further comprising a casing for housing the central processing unit and the input/output interface.
17. The device of claim 14 , wherein the input/output interface is communicatively coupled to the process control system by an Ethernet connection.
18. The device of claim 14 , wherein calculating a first and a second statistical indices for the respective first and second parameters comprises calculating a range and an arithmetic mean of a first sample of the data representative of the first process operating parameter and a second sample of the data representative of the second process operating parameter.