DE19927498A1 - System and procedure for quality control in a production line - Google Patents

Abstract

The invention relates to a system and method for controlling quality on a production line comprising a number of workstations for producing a complex product, in particular a motor vehicle. With increasingly complex products it is necessary for quality assurance purposes to identify and classify any defects and quality complaints that have occurred concerning the product, in order to ensure the complete elimination of said defects and complaints. According to the invention, a number of stationary and/or mobile data entry devices (4 - 8) are provided, both on the production line (10) and at adjacent workstations (2, 3), on which data is inputted for the defects that have occurred. The data entry devices (4 - 8) transmit the inputted data at least to a central processing unit (9) which evaluates said data according to defined selection criteria and transmits the evaluated data, based on the relevance thereof, to output devices (11 - 13) on the production line (10) and at the workstations (2, 3) which are adjacent to said production line. The output devices (11 - 13) output the evaluated data according to defined evaluation criteria.

Description

The invention relates to a system and a method for quality control in one Production line with a variety of work stations to produce a complex Product, especially a motor vehicle.

With increasing complexity of a product, as is especially the case with electronic Devices and vehicles, it is necessary for quality assurance of the product, Errors and complaints occurred, be it defective assembly parts or during the Manufacture or installation of damage that has occurred, can be found quickly and closed systematize to complete elimination of errors and complaints guarantee.

Various methods have become known.

For example, US Pat. No. 4,709,337 describes a method for quality improvement and Correction of errors in a process of an assembly line for the assembly of vehicles proposed, with each workstation in the assembly line with decentralized Input terminals are designed in which an operator can complete a successful termination Steps or errors that have occurred. This data is sent to a Central computer forwarded and collected there. Furthermore, on or in the Assembly line provided rework stations, which also with data terminals are equipped. The central computer sends corresponding to these terminals in the Assembly data recorded error data. After the error has been rectified, a Corresponding information to the central computer via the data terminals of the Given rework.

The input terminals are assigned to a specific workstation and point a set of controls, with each control having a specific error  is assigned to a work step. So the work step just couldn't be successful carried out with errors, the operator actuates the corresponding control element and the error appears on a display.

The identification of the respective vehicle takes place by actuating another one Control element, whereby the saved identification number of the next Vehicle is called.

Such terminals can only be used to a limited extent, namely at the respective workstation become. If an error occurs that is not identified by a control element, the Operator do not enter this error. The same applies to the corresponding Workstation errors that went unnoticed. These can be at a subsequent Assembly station are also not reported to the central computer.

A similar process for quality improvement and troubleshooting is in the US U.S. Patent 5,077,674. This differs from the procedure from US Pat. No. 4,709,337 that the input terminal is another Has control, with its actuation can be signaled that the Assembly work was done entirely at an assembly station, independently whether an error has occurred or not.

Furthermore, from IEE 43, year 1998, No. 12, pages 44 to 46, a method for Quality assurance in the final assembly of motor vehicles known. In each of Areas find the recording of area-related errors via stationary and mobile Input devices instead. Industrial PCs that are connected to such serve as stationary devices Workstations are used where the vehicle is not moving. The mobile devices either carry people with them or are assigned to a vehicle and thus accessible to everyone on the production line. The errors or complaints are recorded with the help of touchscreen-based devices, both a graphical input as well as an input using test reports is possible. The above the stationary and mobile devices entered fault data becomes a central Unit sent, which feeds this data to the corresponding rework zones. In addition, an error can be reported back to the respective workstation.  

The object of the invention is to provide a method and a system for quality assurance create, with the help of a consistent recording of errors found and Complaints about the product in all workstations of the production line, but also in the Production line downstream stations is possible to ensure a quick and systematic Ensure troubleshooting.

The object is solved by the features of claims 1 and 12. Beneficial Further developments and refinements are presented in the subclaims.

According to the invention, the quality control system comprises a number of stationary ones and / or mobile input devices, in which data occurred errors or Complaints can be entered. These input devices can be connected to both Production line itself are arranged, as well as on the production line downstream stations. The data entered are at least one central Processing unit fed, which collects the data and at least according to the type of error and / or the frequency of errors and / or the location of the error on the product and / or the location of the errors occurred in the production line and / or product-related and / or Evaluation period evaluates. The evaluated data are from the central Processing unit depending on its relevance, d. H. according to defined selection criteria at dispensers in the production line and / or at dispensers of Production line sent downstream stations, which in turn the evaluated data output. Different media such as screens, Printers, etc. are used.

Furthermore, the invention relates to a method for quality control, in which in a first step data of errors or complaints about a product a stationary or mobile input device can be entered. This can be done at any point the production line, regardless of which workstation the error occurred is. In addition, an input of data about errors or complaints that have occurred is pending Downstream stations possible, these stations also in Sales facilities and workshops can be arranged. This gives the advantage that the "life" of the product is precisely documented.  

In a second step, the data entered is sent to at least one central Processing device sent, which the transmitted data according to the evaluates different points of view. Examples are the type of error, the Error rate, the location of the error that occurred in the production line, a product-related evaluation as well as the period of origin specified.

In the next step, the evaluated data is transferred depending on their relevance to output devices in the production line and / or the Production line downstream stations by these dispensers are output, whereby the output can take place automatically as well as on demand.

According to an advantageous embodiment of the invention, the data transmission takes place both between the stationary and / or the mobile input devices and the central one Processing unit and / or between the central processing device and the Output devices via a radio link. This gives everyone the opportunity Arrange components of the system according to the invention variably. However, too other transmission media can be used.

According to a further embodiment of the invention, the data of the errors that have occurred related to the respective product in the stationary and / or mobile input devices entered. This creates the possibility that, for example, in the Production line or the rework stations downstream of the production line Receive information about which errors have occurred on which specific product, in order to be able to eliminate these errors systematically and consistently.

An electronic entry is made beforehand for the product-related entry of the errors that have occurred Product identification from the input device, by reading one attached to the product Identification codes. The most varied of options from the prior art Technology known. One possibility is in the German patent application DE 196 07 294 A1.

To make it easier to enter the data of the errors or complaints that have occurred, too for inexperienced personnel, parts and / or are preferably in the input devices Assemblies of the product and / or the product itself is stored graphically and on an in  display devices integrated into the input devices can be displayed. The error entry can thus directly on the displayed part or assembly Touchscreen entry done. The parts, assemblies and / or the product are on the display device is preferably shown in two or three dimensions.

Another possibility is the data of the errors or complaints that have occurred to enter is to install a targeted menu query in the input devices.

According to a further embodiment of the invention, the output devices are Production line display devices that are assigned to a respective work station, these display devices are preferably at a clear location arranged screens trained, which can be easily viewed by the staff of the workstation are. The evaluated data are displayed on the workstations at least according to the frequency of errors and / or the type of error and / or the location of the error displayed on the work steps to be carried out at the respective work station. This gives the personnel working there the possibility of routine errors or on Be aware of errors that have occurred during the production process.

According to a configuration of the display devices of the respective work station, this is Product or product parts related to those to be performed at the work station Work steps can be represented graphically. The errors that occurred at the workstation are according to defined criteria on the graphic representation of the product or the Product part displayed.

The evaluated data of the errors and complaints that have occurred are processed by Output device of the stations downstream of the production line preferably product-related output.

The advantages of the invention are in particular the great flexibility of data entry, where a complaint or error is noticed, it can also be entered, the simple handling of the input devices, the retrospective display of errors and hence the quick elimination of routine and systemic errors as well the fast and consistent transmission of errors to downstream stations such as Rework places.  

The invention will be described in more detail below using an exemplary embodiment become. The associated drawings show:

Fig. 1 shows a schematic representation of the system for quality control,

Fig. 2 is a flow of data input in an input device,

Fig. 3 shows a display image for an input device,

Fig. 4 shows a display image for an input device,

Fig. 5 shows a display image with a graphical representation for an input device,

Fig. 6 shows a display image for fault types of an input device,

Fig. 7 shows a further flow of data input in an input device,

Fig. 8 shows a display image for the labeling of bug fixes an input device,

Fig. 9 is an output device for a workstation in the production line and

Fig. 10 shows another output device for a workstation in the production line.

In Fig. 1, a production line, which is shown schematically as line 10 , with work stations 1 a to 1 e of a motor vehicle assembly is shown, the number of work stations is intended to represent only one example. The production line 10 are reworked 2 a to 2 c downstream. In addition, 3 denotes a station of a remote workshop. A stationary input device 5 is assigned to work station 1 e. Furthermore, there are mobile input devices 4 on the production line, so-called handheld devices, which are not assigned to a workstation 1 . An assignment to certain people is conceivable. However, this is not a requirement. The input devices 6 and 7 as well as the input device 8 at the rework stations 2 a to 2 c and the workshop 3 can be designed to be both mobile and stationary.

According to the exemplary embodiment, the input devices 4 to 7 communicate with the central processing device 9 wirelessly, here a radio connection has proven to be advantageous. In the exemplary embodiment, the distant input device 8 of the workshop is connected to the central processing unit 9 via a data line.

After the data about errors or complaints that have occurred have been entered into individual input devices 4 to 8 and transmitted to the central processing unit 9 , the latter evaluates the data according to certain criteria and test routines, e.g. B. based on the type of error, the frequency of errors, the location in the production line, related to the product and in what period (for example, in which shift) the error occurred. After their evaluation, the evaluated data are sent according to defined specifications and relevance to the output devices 11 , which are assigned to work stations, and to the output devices 12 of the rework stations according to other specifications. Further special evaluation criteria can be provided for the output device 13 of the workshop 3 .

The output devices 111 are preferably designed as display devices that can be easily seen by the staff of the respective work station. In the exemplary embodiment, plasma screens are used, on which the evaluated data of the errors or complaints that have occurred at the respective work station 1 a to 1 e are displayed, so that the person of the work station receives a review of the work done at the work station. The detailed type of display will be discussed later.

The output devices 12 and 13 at the rework stations 2 a to 2 c and in the workshop 3 can also be display devices and, for example, printers, and the combination of a plurality of output devices is also conceivable. The evaluated data is output here in relation to the product.

In FIG. 2, the flow is a possible input routine for inputting errors and complaints in a mobile or stationary input device 4 is shown to 8. After an operating element provided on the input device or a touchscreen input has been actuated, the input routine starts with step 14 . In step 15 , the operator identifies himself as an authorized person by entering an identifier and a password. The process jumps to step 16 , in which the current vehicle is identified by reading an identifier from the input device from a storage medium arranged on the vehicle. This can be done automatically or by manually triggering an input command. In step 17 , the vehicle model is selected in which a selection of the vehicles manufactured in the production line appears on the display device 21 of the input device ( FIG. 3). Step 17 can be omitted if the vehicle identification number already contains a corresponding identification for the vehicle model. Step 18 is followed by the selection of the fault location on the vehicle. This selection can also be carried out via a selection menu 22 on the display device 21 , by selecting the corresponding fault location via a touchscreen input or via a menu query using a manual control element ( FIG. 4).

Particularly in the case of components such as bonnets, fenders, etc., where damage or a complaint is difficult to define for a precise fault location via a selection menu, the respective component 23 , in certain cases also the entire product, is displayed on the display device 21 of the input device 4 to 8 is shown graphically. An example is shown in FIG. 5. Here, the rear part 23 of the assessed vehicle is shown next to the vehicle identification number 24 . The operator can narrow the location of the error very precisely by means of a touchscreen input on the display device 21 . In the next step 20 ( FIG. 2), the type of error is determined via a selection menu 25 on the display device 21 ( FIG. 6).

After entering the type of error, the process automatically jumps to step 18 , entering the location of the error, until the operator terminates the input process by actuating an "exit" control element.

Fig. 7 shows the sequence of a possible input routine for entering or correction of faults or complaints in a stationary input device 6 to 8 of a rework place 2 or in a workshop. 3 Errors are entered in the same way as in the input routine according to FIG. 2. In addition, however, there is the possibility of identifying corrected errors as such or deleting them. After starting 14 and entering the authorization in step 15 , the vehicle is again identified in step 16 by adopting the vehicle identification number and the vehicle model or the vehicle equipment is entered in step 17 (if this is not yet included in the vehicle identification). Now the error location is selected in step 18 and the error is deleted or marked as eliminated via an input in step 26 . For this purpose, manual operating elements 27 , 28 can be provided on the input device 6 to 8 or a touchscreen input can be made on the display device 21 ( FIG. 8). The error is shown on the display device 21 as eliminated 29 or as deleted 30.

In Fig. 9 an output device 11 is shown a work station in the production line of the vehicle assembly. The output device is designed as an LCD screen and shows a list 31 , the complaints that have occurred at the workstation with the location and type of error, and a bar diagram 32 assigned to the list 31 , which shows the frequency of the errors in relation to the error that has occurred. In the bar chart 32 , the errors are classified, for example, whether it is an error caused by the workflow. Furthermore, a display field 33 , which represents the acquisition period, and a display field 34 , which shows the number of vehicles manufactured in the acquisition period, are provided.

Another type of display of the errors that have occurred at a work station is shown in FIG. 10. The output device 11 shows the manufactured vehicle in two dimensions in a so-called "butterfly display", the number of errors 35 being entered directly on the display. For example, the errors are also classified using different color representations. Furthermore, a display field 36 is provided, which shows a legend of the types of errors related to the error displayed in each case.

Claims (25)

1. System for quality control in a production line ( 10 ) with a plurality of workstations ( 1 ) for the production of a complex product, in particular a motor vehicle, with a number of stationary and / or mobile input devices ( 4-8 ), in which data errors occurred or complaints can be entered and which transmit the entered data to at least one central processing unit ( 9 ) which evaluates the data according to defined evaluation criteria and which evaluates the evaluated data depending on their relevance to output devices ( 11-13 ) of the production line of downstream stations ( 2 , 3 ) and / or sends the relevant workstations ( 1 ), which output the evaluated data according to defined evaluation criteria. 2. System for quality control according to claim 1, characterized in that the data transmission between the stationary and / or mobile input devices (3-8) and the central processing unit (9) and / or between the central processing device (9) and the output devices ( 11-13 ) via a radio link. 3. System for quality control according to claim 1 or 2, characterized in that the data of the errors that have occurred can be entered in relation to the respective product into the stationary and / or mobile input devices ( 4-8 ), with an electronic product identification from the input device ( 4 -8 ) by reading an identification code stored on the product. 4. System for quality control according to one of claims 1 to 3, characterized in that in the input devices ( 4-8 ) parts and / or assemblies of the product and / or the product are graphically stored and can be displayed on an integrated display device ( 21 ) and the data of the errors or complaints that have occurred can be input via a touchscreen input on the displayed part or the displayed assembly. 5. System for quality control according to claim 4, characterized in that the parts and / or assemblies and / or the product on the display device ( 21 ) can be represented in two or three dimensions. 6. System for quality control according to one of claims 1 to 5, characterized in that the data of the errors or complaints that have occurred can be entered via a menu query in the stationary and / or mobile input devices ( 4-8 ). 7. System for quality control according to one of claims 1 to 6, characterized in that the evaluation unit ( 9 ) the transmitted data at least according to the type of error and / or the frequency of errors and / or the location of the error occurred in the production line and / or the location evaluates the error that has occurred on the product and / or the period of origin and / or product-related. 8. System for quality control according to one of claims 1 to 7, characterized in that the output devices ( 11-13 ) the evaluated data at least according to the type of error and / or the frequency of errors and / or the location of the error occurred in the production line and / or the location of the error that occurred on the product and / or the period of origin and / or product-related. 9. System for quality control according to one of claims 1 to 7, characterized in that the output devices ( 11-13 ) of the production line are display devices which are assigned to a respective work station. 10. System for quality control according to claim 8, characterized in that the Display devices are designed as screens. 11. System for quality control according to claim 9 or 10, characterized in that the evaluated data on the display devices assigned to a respective work station ( 11 ) at least according to the frequency of errors and / or the type of error and / or the error location on the product with respect to that at the work steps to be carried out for each work station ( 1 ) can be displayed. 12. System for quality control according to one of claims 9 to 11, characterized in that on the display device ( 11-13 ) of the respective work station ( 1 ) the product or product parts can be graphically represented in relation to the work steps to be carried out at the work station and the Errors that have occurred at the workstation can be displayed on the graphic representation of the product or of the product part, at least according to the frequency of errors and / or the type of error and / or the location of the error on the product. 13. System for quality control according to one of claims 1 to 12, characterized in that the stations downstream of the production line are rework stations ( 2 ) and / or workshops ( 3 ) and / or sales units, on the output devices ( 12 , 13 ) of which the evaluated data are product-related. 14. Method for quality control in a production line ( 10 ) with a plurality of work stations ( 1 ) for the production of a complex product, in particular a motor vehicle, characterized by the steps:

• a) entering data of errors or complaints about a product into a stationary / or mobile input device ( 4-8 ),
• b) transmission of the entered data to at least one central processing unit ( 9 ),
• c) evaluation of the transmitted data in the central processing unit ( 9 ) according to defined evaluation criteria,
• d) transmission of the evaluated data depending on their relevance to output devices ( 11-13 ) in the production line ( 10 ) and / or the downstream production stations ( 2 , 3 ) and
• e) Output of the evaluated data according to defined output criteria by the output devices ( 11-13 ).

15. The method according to claim 14, characterized in that the data transmission between the stationary and / or the mobile input devices ( 4-8 ) and the central processing unit ( 9 ) and / or between the central processing device ( 9 ) and the output devices ( 11- 13 ) is carried out via a radio link. 16. The method according to claim 14 or 15, characterized in that the data of the errors or complaints that have occurred relating to the respective product are input into the stationary and / or mobile input devices ( 4-8 ), previously having an electronic product identification from the input device ( 4-8 ) by reading an identification code stored on the product. 17. The method according to any one of claims 15 to 16, characterized in that parts and / or assemblies of the product and / or the product are stored graphically in the input devices ( 4-8 ) and on a display device ( 21 ) of the input devices ( 4- 8 ) are displayed and the data of the errors or complaints that have occurred are entered via a touchscreen input on the displayed part or assembly or product. 18. The method according to claim 17, characterized in that the parts, assemblies and the product on the display device ( 21 ) are shown in two or three dimensions. 19. The method according to any one of claims 15 to 18, characterized in that the data of the errors or complaints that have occurred are entered via a menu query in the stationary and / or mobile input devices ( 4-8 ). 20. The method according to any one of claims 15 to 19, characterized in that the data of the errors or complaints occurred regardless of the causing work station ( 1 ) in the production line ( 10 ) as well as on the production line downstream stations ( 2 , 3 ) are entered . 21. The method according to any one of claims 15 to 20, characterized in that the transmitted data in the evaluation unit ( 9 ) at least according to the type of error and / or the error frequency and / or the location of the error occurred in the production line ( 10 ) and / or the location of the error that occurred on the product and / or the period of origin and / or product-related. 22. The method according to any one of claims 15 to 21, characterized in that the evaluated data by the output devices ( 11-13 ) at least according to the type of error and / or the error rate and / or the location of the error occurred in the production line ( 10 ) and / or the location of the error that occurred on the product and / or the period of origin and / or product-related. 23. The method according to any one of claims 15 to 22, characterized in that the evaluated data on the output devices ( 11 ) assigned to a respective workstation ( 1 ) of the production line ( 10 ) at least according to the frequency of errors and / or the type of error and / or the location of the error are displayed in relation to the work steps to be carried out at the work station ( 1 ). 24. The method according to claim 23, characterized in that the output device ( 11 ) of the respective work station ( 1 ) the product or product parts in relation to the work steps to be carried out at the work station ( 1 ) are graphically output and at the work station ( 1 ) errors or complaints that have occurred are shown on the graphical representation of the product or of the product part. 25. The method according to any one of claims 15 to 24, characterized in that through the output devices ( 12 , 13 ) of the stations downstream of the production line ( 2 , 3 ), the evaluated data are output product-related.