WO2001050204A2

WO2001050204A2 - Production line stability tool

Info

Publication number: WO2001050204A2
Application number: PCT/US2000/033400
Authority: WO
Inventors: Lorenzo Vera Melgarejo
Original assignee: General Electric Company
Priority date: 1999-12-30
Filing date: 2000-12-08
Publication date: 2001-07-12
Also published as: AU2907101A; WO2001050204A3

Abstract

A method and system for monitoring production lines (10) and the like, the method and system providing on-line real time production line status using optically distinct display outputs (16) to provide an easily visually interpretable status indication. If actual production on a particular line is outside the production line's upper and lower target limits, the line output is displayed (16) in a first optically distinct manner. If the actual production is between the limits, or above the limits, the line output is displayed in second or third optically distinct manners, respectively.

Description

PRODUCTION LINE STABILITY TOOL

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of provisional patent application Serial No. 60/173,726 filed December 30, 1999, the disclosure of which is incorporated herein by reference.

BACKGROUND OF THE INVENTION

The present invention is related generally to monitoring and control systems. More particularly, the presen* invention is related to methods and systems for monitoring production lines in a manufacturing environment.

Systems are known for controlling manufacturing processes. For example, U.S. Patent 5,768,119 to Havekost et al. discloses a process control system that includes an alarm priority adjustment. The disclosure is directed to systems which monitor and uniformly display diagnostic information for devices of multiple different types, such as valves and switches. Various users of the system can prioritize the alarm and event information that is displayed. A user can set a desired alarm priority, selecting more important alarms for more urgent display and assigning a lower display status to less important events. When a particular user logs on to the system, the user is associated with a display configuration for displaying alarm and event information that is pertinent to that particular user.

U.S. Patent 5,351,195 to Sherman discloses a method for improving manufacturing processes in a factory. The method is performed by inputting an output capacity level for the factory, and a selected parameter for improvement; determining whether a maximum possible variation of the selected parameter would achieve the output capacity level; determining an achievable capacity output level when the maximum possible parameter variation does not allow for the desired output capacity level; determining an amount of improvement required to achieve the output capacity level when the maximum possible improvement meets or exceeds the output capacity level; and adjusting the processes of one or more factory workstations to implement the parameter improvements.

U.S. Patent 4,802,094 to Nakamura et al. discloses a process monitoring apparatus for process management in production and assembly lines. More particularly, this patent discloses a method and apparatus for monitoring a process earned out along a line which branches and joins in a complicated manner, such as in the case where a plurality of parts or products of various kinds are moved in a line while they are joined together, or a lot of joined works is divided into sub-lots. The apparatus includes a first memory for holding facility-specific data for each of a plurality of facilities in a production line; a second memory for holding tracking conditions representing a detection of movement flow of works between facilities; third, fourth, and fifth memories holding management data, program triggering data for triggering a program to define contents of an operation represented by the management data, and process status data (including the movement detection signal), respectively; means for extracting the management data from the third memory and for determining which tracking conditions have been met; and a processor for executing a process corresponding to the contents of the first, second, and fourth memories.

While techniques, such as those disclosed above, for providing control in various environments are known, there is a continuing need for improved control systems. Such improved control systems are highly desirable in the manufacturing environment, where many production lines are monitored by printing out a report of production data for a particular production line or lines, perhaps performing numerous calculations, and making decisions about whether and how to adjust certain aspects of a production line. In an environment where quick and efficient operation of a production line is cntical, it is highly desirable to determine quickly and efficiently whether one or more production lines is producing product at a level which threatens the stability of the line or an overall production process. The techniques described above do not adequately address these problems.

BRIEF SUMMARY OF THE INVENTION The present invention overcomes the above-noted problems, and achieves additional advantages, by providing for a method, system and program for monitoring one or more production lines and providing optically distinct indications of production line status to enable a person monitoring production lines to determine if any production lines are in a potentially unstable state.

According to preferred embodiments, the method can be implemented by determining first and second threshold production values (e.g., upper and lower production limits) for each line: determining an actual production value from each of the one or more production lines; comparing the actual production values from each line with the first and second thresholds for each line; and for each line, providing a first output if the actual production value is below the first threshold, providing a second output if the actual production value is between the first and second thresholds, and providing a third output if the actual production value is above the second threshold. The outputs are preferably optically distinct outputs on a display screen to enable a viewer to quickly and easily determine if one or more of the production lines are in a potentially unstable state.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention can be understood more fully by reading the following Detailed Description of preferred embodiments in conjunction with the accompanying drawings, in which:

FIG. 1 is a block diagram of an arrangement in which one or more embodiments of the present invention can be implemented;

FIG. 2 is a flow chart describing a method according to an embodiment of the present invention; and

FIGs. 3 and 4 are sample display screens displaying an output according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

Referring now to the accompanying drawings, FIG. 1 is a block diagram showing one arrangement in which an embodiment of the present invention can be implemented. The diagram includes a plurality of production lines 10 having associated sensors 12 which are communicatively connected to a computer system 14. The computer system 14 has one or more associated displays 16 for displaying information to one or more associated persons. It will be appreciated that the computer system 14 can be a computer network such as the Internet or an intranet (a secured network accessible only to particular persons). While the sensors 12 can be selected and implemented to measure any relevant production line parameters, it is assumed for purposes of explanation that the sensors 12 monitor the total output of each production line. In the case of manufacturing chemicals, quantities are typically measured in kilograms. Thus, in this example, the sensors 12 sense the output of each line, and provide this data over an appropriate communications link (which may be a hard-wired communication link, wireless communication link, or any other appropriate communications link including an intranet or the internet) to the computer system 14, which processes the data and displays appropriate outputs on one or more of the displays 16. The computer system 14 can process the data according to the methods and programs disclosed below.

The system of FIG. 1 can be implemented using automatic industrial monitoring (AIM) as is known in the art. Alternatively, the system of FIG. 1 can be implemented using the General Electric Cimplicity® system, or other suitable techniques for sensing inputs and outputs, and performing the desired calculations and other processing.

Referring now to FIG. 2, a flow chart describing a method according to one embodiment of the present invention for monitoring output of one or more of the production lines in the example of FIG. 1. This method can be implemented by a suitable software program, which includes instructions for carrying out the various steps of the method, and which resides in a memory (not shown) associated with the computer system 14. The process starts in step 200, and proceeds to step 202, in which the computer system 14 determines whether the current time is equal to one or more predetermined default times. The predetermined default times would typically be at the end of a measuring interval (e.g., one hour, one day, or other relevant interval). If the current time is equal to a predetermined default time, the method proceeds to step 204, where all calculations are reset, and then the method returns to step 202.

If the computer system 14 determines in step 204 that the current time is not a predetermined default time, then the computer system 14 retrieves first and second threshold values Ql and Q2 (which can be upper and lower line production limits, or other suitable criteria) from an associated memory. The method then proceeds to step

206, where the computer system 14 determines (e.g., from the outputs of the sensors 12), whether the actual production of the line is smaller than the first threshold. If so, this indicates a undesirable or potentially unstable situation, and the computer system 14 causes one or more of the display screens 16 to provide a first display indication in step 208. According to one embodiment of the present invention, one or more of the display screens 16 display in graphical form a plot of line output versus time; an exemplary plot will be described in more detail below. The first display indication in this example is causing the plot or portion thereof where the production line output is below the first threshold to be shown in a first optically distinct color (e.g., red). After step 208 is completed, the method returns to step 202.

If the computer system 14 determines in step 206 that the actual production value is not below the first threshold, then the method proceeds to step 208 where the actual production value is compared to the second threshold. That is, the computer system 14 can determine whether the actual production value is between the first and second thresholds. If the actual production value of the line is between the first and second threshold values, the method proceeds to step 210, where the computer system 14 provides a second display indication. In this example, the second display indication can be causing the plot or portion thereof showing the actual production value to be between the first and second thresholds to be shown on the display screen 16 in a second optically distinct color (e.g., yellow). After step 210 is completed, the method returns to step 202. If the computer system 14 determines in step 208 that the actual production value is not between the first and second threshold values, the method proceeds to step 212, where the computer system determines whether the actual production value is larger than the second threshold. If the actual production value is larger than the second threshold, indicating an undesirable and/or potentially unstable condition, the method proceeds to step 214, where the computer system 14 provides a third display indication on one or more of the displays 16. In this example, the third display indication can be provided by causing the plot or portion thereof showing the actual production value to be above the second threshold to be shown in a third optically distinct color (e.g., green). After step 214, the method returns to step 202.

If the computer system 14 determines in step 212 that that actual production value is not larger than the second threshold value, an error has occurred, and the process returns to step 202.

It shoulcrbe appreciated that by providing a graphical display output and varying the color of portions of the graphical display where the actual production values indicate undesirable conditions, an engineer can quickly and easily identify specific production lines which are potentially unstable.

Referring now to FIGs. 3-4, first and second exemplary display outputs are shown. FIG. 3 is a summary display which identifies specific production lines of interest in a first column, the second threshold (e.g., the maximum desirable production value) in a second column, the first threshold (e.g., the minimum desirable production value) in a third column, an actual production value in a fourth column, and a difference value in a fifth column. Additional columns are provided to show a total quantity of reextrusion and rejected product per line in the relevant time period, and a total produced quantity, determined in this example as a sum of the actual production value and the total quantity of reextrusion and rejected product. Finally, this exemplary display includes links, which may be in hypertext markup language (HTML) or otherwise suitably implemented, to historical line data providing a graphical display of line output for the associated production line over time. The production line identification for each line in the first column of FIG. 3 can advantageously be displayed in optically distinct colors consistent with the current stability or other status of each production line.

FIG. 4 shows a second exemplary display, which can be presented on the display 16 in response to a system user clicking on one of the links in the exemplary display of FIG. 3. The second exemplary display of FIG. 4 includes a graph plotting the actual production value over time for one or more particular production lines. It will be appreciated that the plots, or relevant portions thereof, can be displayed in different optically distinct colors to quickly and easily indicate to a system user the stability or other status of the production line.

One exemplary source code listing for performing the calculations contemplated in the foregoing examples is provided as follows:

! Calculation of Kg difference to achieve daily objective

L23_DIFERE$MV = (L23_KGPROD$MV - L23_TOTALR$MV) - L23_Q3$MV

ICalculation of good Kg produced

L23_KGGOOD$MV = L23_KGPROD$MV - L23_TOTALR$MV

ICalculation of the day_to_date production

SPAN = (NOW: - TODAY( 17:00))

IF (HOUR$MV .LT. 17) THEN

SPAN = (NOW: - YESTERDAY( 17:00))

ENDIF

L23_KGPROD$MV=(XY214126$PV[H,'H_TWAV',SPAN,NOW:])*SPAN

END Such source code or other suitable source code can be stored and implemented in the computer system 14 of FIG. 1.

It should be appreciated that the foregoing description has assumed the measurement of production quantities in each of a plurality of production lines, and that there exist two relevant thresholds- that is, upper and lower production quantities.

However, the principles of the present invention can easily be applied to monitoring values other than production quantities. For example, quality values such as item size, color, or other relevant qualitative values can be monitored. Further, it may be desirable to monitor the production lines based on more than two threshold values. For example, it may be desirable to measure production item size or weight, and to classify the produced items in one of many categories. Items so classified can be directed to locations corresponding to their category. Other modifications will also be apparent to those of ordinary skill in the art.

While the foregoing description includes many details, it is to be understood that these are provided for purposes of explanation only, and that such details do not constitute limitations on the invention. The examples above can be widely varied without departing from the spirit and scope of the invention, as defined by the following claims and their legal equivalents.

Claims

WHAT IS CLAIMED IS:

1. A method for monitoring one or more production lines (10), comprising the steps of:

determining first and second threshold production values for each line;

determining an actual production value from the one or more production lines;

comparing the actual production values from each line with the first and second thresholds for each line; and

displaying, for each line, a first output if the actual production value is below the first threshold, displaying a second output if the actual production value is between the first and second thresholds, and displaying a third output if the actual production value is above the second threshold.

2. The method of claim 1, wherein the outputs are optically distinct visual outputs.

3. The method of claim 1, wherein the step of determining first and second threshold production values is performed by retrieving stored values from a memory.

4. The method of claim 1 , wherein the first and second production threshold values are lower and upper stability limits, respectively, for the associated production line.

5. The method of claim 1, further comprising the step of resetting the actual production values upon the expiration of a predetermined time interval.

6. The method of claim 5, wherein the predetermined time interval is one day.

7. The method of claim 1 , wherein the step of displaying is performed by generating a display on a display screen associated with a computer system.

8. The method of claim 7, further wherein the step of displaying is performed by:

generating a table, the table including an identification of one or more specific lines, one or more threshold status parameters, one or more actual status values, and a display link to additional information for the one or more of the one or more specific lines; and

displaying the table on the display screen.

9. The method of claim 8, wherein the identification of the one or more specific lines is displayed as a first, second, or third output based on the status of the specific line.

10. The method of claim 8, wherein the additional information is a graphical plot of actual production line output over time.

11. A system for monitoring a plurality of production lines (10), comprising:

one or more sensors (12) associated with each production line, each sensor measuring a production line parameter;

a computer system (14) communicatively coupled to receive an output for each of the sensors; and

one or more display devices (16) in communication with the computer system, each display device operable under control of the computer system to display status information for one or more of the production lines, the status information being derived by the computer system from the sensor output,

wherein the computer system provides first, second, or third distinct visual outputs on one or more of the display devices for each of one or more production lines depending upon whether a production line parameter measured by the one or more sensors is below a safe range, within a safe range, or above a safe range.

12. The system of claim 11, wherein the first, second, and third distinct visual outputs included first, second, and third optically distinct colors.

13. The system of claim 11, wherein the distinct visual outputs are displayed as a table including an identification of one or more specific lines, one or more threshold status parameters, one or more actual status values, and a display link to additional information for the one or more of the one or more specific lines.

14. The system of claim 13, wherein the additional information includes a graphical plot of the one or more actual status values over time.

15. The system of claim 14, wherein each graphical plot includes at least one portion which is optically distinct from a remainder of the plot to indicate a status of the pioduction line.

16. The system of claim 11, wherein the safe range is defined by first and second threshold values stored by the computer system.

17. The system of claim 11, wherein the displays are reset after a predetermined time interval expires.

18. The system of claim 11, wherein the computer system is communicatively coupled to the display devices over the internet.

19. The system of claim 11, wherein the computer system is communicatively coupled to the display devices over an intranet.

20. A computer product including machine-readable code, comprising:

one or more instructions for determining a current time;

one or more instructions for determining whether an actual production quantity of a production line is less than a first threshold, and for generating a first display output if the actual production quantity is less than the first threshold;

one or more instructions for determining whether the actual production quantity is between the first threshold and a second threshold, and for generating a second display output if the actual production quantity is between the first and second thresholds; and one or more instructions for determining whether the actual production quantity is greater than the second threshold, and for generating a third display output if the actual production quantity is greater than the second threshold.

21. The product of claim 20, wherein the first, second, and third display outputs are provided in a table presented on a display device, the table including an identification of one or more specific lines, one or more threshold status parameters, one or more actual status values, and a display link to additional information for the one or more of the one or more specific lines, and wherein the first, second, and third display outputs are optically distinct identifications of each of the one or π.ore specific lines.

22. The product of claim 21, wherein the display link is provided in hypertext markup language.

23. The product of claim 20, wherein the display output is provided over the Internet.

24. The product of claim 20, wherein the display output is provided over a limited- access intranet.

25. A method for monitoring one or more production lines, comprising the steps of:

determining an actual measurement value for each production line;

comparing the actual measurement value from each line with a plurality of predetermined threshold measurement values for each line; and

displaying, for each line, one of a plurality of outputs based on the step of comparing, the plurality of outputs being one more than the plurality of predetermined threshold values.

26. The method of claim 25, wherein the plurality of outputs are outputs of optically distinct colors on a computer display screen.

27. The method of claim 25, wherein the threshold measurement values are quality measurement values.

28. The method of claim 25, wherein the threshold measurement values are production quantity values.

29. The method of claim 25, further comprising the steps of: directing the output of each production line to a location corresponding to displayed output of the line.