zenon - all the key figures at the press of a button at Volkswagen's plant Emden (Germany)

The Volkswagen plant in Emden has a daily capacity of 1,200 vehicles, and has produced more than 9.5 million vehicles since the plant was opened in 1964. The Passat Limousine has been built in Emden since 1977, and the Passat Variant is only built here. The Emden site has been the leading plant in the world for this successful model.

zenon sets new standards

Several generations of Passats have been manufactured here. Half way through 2003 the 12 millionth Passat, and in Septem-ber 2004 the 13 millionth Passat from any Volkswagen plant was produced. The sixth generation of Passat Variant was launched in August 2005. In November 2007 Volkswagen in Emden pro-duced its 15 millionth Passat worldwide. 2008 was the launch year for the new model, Passat CC, that is produced exclusively in Emden. The launch of a new model is usually also the event that triggers investment in new machines and software. Volkswagen in Emden took the production of the new series of Passat models as a trigger for modernising the assembly plant and standardising the base software as well as the overlaid visu-alisation software. Here, the zenon software from COPA-DATA, which is used for the central plant monitoring system, has been setting new standards in production.

Consistency in the VW passat assembly process

In the assembly process at Volkswagen’s Emden plant zenon is now responsible for a total of four assembly shops as well as for communication with high level and low level systems, for the entire flow of information in the assembly plant and for preparing all the data for use in a high-performance, effec-tive information system. There was no other system that was capable of satisfying the requirements of Volkswagen’s project managers. An important evaluation criterion for zenon was its use of different controllers and its extensive integration ability. “Because of the increased volume of data in modern plants we were not able to capture data from all sections of the plant and to visualise it all. The systems were overloaded and grew con-siderably slower. A new solution was required”, explains Mario Ewen, project leader at Volkswagen in Emden. In this case more than 120 controllers are involved – different models from dif-ferent manufacturers. zenon visualises and oversees the entire production flow using more than 50,000 variables, which are transferred to zenon. The entire assembly process is now vis-ualised with 172 displays. Another incentive for developing a new application was the fact that the previous operating sys-tem, Windows NT, was to be discontinued. What’s more, one of the tools used was no longer supported by the manufacturer. “Overall, the applications from our previous providers were no longer up to the job with the modern, upgraded structure. We compared a number of systems, taking into account our require-ments, and reached the conclusion that zenon met all the crite-ria on our list. We are now using a consistent, standard solution for the entire assembly process”, explains Georg-Joachim Loger, maintenance engineer at Volkswagen’s Emden plant. This project was implemented by process management staff and production facilities management staff working with staff from COPA- DATA. Volkswagen was especially happy with the efficient direct approach and the readiness of the COPA-DATA team to try to give us everything we wanted as well as to incorporate chang-es as they presented themselves in the course of the project.

Distributed, secure and functional

zenon features all the modern technology that a car manufac-turer could possibly ask for. The Volkswagen software is config-ured as a client/server system with redundancy, and is therefore fail-safe. The internal network at Volkswagen now incorporates eight zenon clients. As well as the redundant server pair, there is also a database and a web server. The COPA-DATA web server serves 100 web clients simultaneously. The various process dis-plays are brought up according to the specific task or functional area. For storing and archiving data, the managers at VW decid-ed on a (Microsoft) SQL-Server. The database is automatically populated from the zenon-SQL-Server connector, which also en-sures that the data is read back automatically. Also included is a powerful user management module for defining access rights to the project and system. The user management module is used to specify which users are permitted to view or modify which functions – such as the shift schedules.

Well-thought-out project structure

The umbrella project, which integrates all the systems in the four assembly shops, includes the system overview displays, the industrial performance analysis, the production and facility manager (for the shift models), the higher-level alarm manage-ment, the chronological events list, counters and plant down-time, plus the initial project for the web client. The individual sub-projects include the system displays with detailed informa-tion, the driver links and control variables, alarm zones and the plant’s shift reference.

zenon – successes become measurable

One of the important goals for the new overall system at Volkswagen was to gain clear and total control over the assem-bly processes, both for management and for those working in the assembly shop. One of zenon’s exceptional strengths is its ability to manipulate large volumes of data and to display them in a useful format to managers or those working in the plant. Volkswagen’s main interest for its Emden plant lay in presenting the key figures for the production process and output in the form of graphs and tables. The car manufacturer can now use these key figures to see how cost-effectively the assembly shop is op-erating. In other words, results become measurable. The key fig-ures might, for instance, include target and actual values for the overall life of a production line, possible differences, the cycle times, the setting up of events in the plant and their causes, and the number of finished cars. Mario Ewen explains: “Monitoring the key figures ensures that the assembly process is running as efficiently as possible, and at full capacity. This system provides us with an overview of all the important information, allowing us to carry out detailed analyses and react quickly to events as necessary.” Volkswagen could also use this data to detect any delays in the course of the assembly process and the causes, allowing an appropriate response. The integrated soft PLC, straton, which complies with the IEC standards, is used to calcu-late the buffer, unit, and output counters. To ensure that all the key figures reflect the assembly processes exactly, Volkswagen uses an additional zenon module. The production and facility scheduler (PFS) controls the chronological sequence of opera-tions in Emden: at this plant a number of working hour models (shift system, lengths of breaks, etc.) are used. The shift hours entered from the PFS can be classified, grouped and evaluated. They are also fed into the performance calculations. “When all the figures are combined, they tell the story of how many cars we are actually producing. The opportunities for evaluating and monitoring our assembly processes are more detailed and so-phisticated than ever before”, observes Mario Ewen.

All the key figures, clearly presented and ready for use

VW managers can view all the key assembly figures in either table or graph form. Individual users can choose how they want the information to be presented. They can also select from many time scales, and different periods of time can be compared with one another. In this way, Volkswagen workers have access to extensive and at the same time highly condensed information that is available at the press of a button in the form of lists and analyses.

 The report generator shows the archive entries in table form, and outputs the reports in HTML format - likewise either as a graph or a table. The Extended Trend module is provided for preparing data in graph form. At runtime users can arrange for various graphs to be displayed, and even for more than one graph to be compared. This ensures that all the relevant opera-tors can view and use analyses, reports and graphs. “The central plant monitoring application is a tool for improving availability”, explains Mario Ewen.

Total control

The higher-level visualisation is now also used as a central point for all events in the plant and system messages. Volkswagen used to operate two systems for this purpose, but these have now been replaced by a single standard system. “As well as the system and plant monitoring we also wanted detailed analyses – on the one hand to ensure maximum availability and on the other hand to exploit any potential for optimisation”, explains Mario Ewen of Volkswagen. All the operators now know in-stantly what they should do if they receive a system message, and can respond straight away.

 Around 5,500 operating messages and system messages per day are produced by the assembly lines in Shops 1 (engine and gearbox), 2 (main assembly, drive assembly, disks, cockpit, etc.) 7 (headlamps, batteries, seats, wheels, doors, etc.) and 16 (ini-tial assembly following paint). All the information is on hand to enable statistical evaluation and analysis with the industrial performance analyser. This information can also be viewed in the form of bar charts or pie charts. Filtering options enable online alarms, historical alarms, pending alarms or reset alarms to be shown, and to specify their display order: by time, class or priority.

 At Volkswagen the alarms are also cleaned up at a break or shift change. This overlaid cleanup process ensures that overlap-ping messages are not only added, but that the net downtimes are taken into account in calculating the duration of an alarm. Every alarm that has caused a downtime is stored along with the possible discrepancy in unit numbers. The discrepancies are evaluated either individually or in total using the line, time, and shift plan filters, and are displayed on a zenon screen.

Optimising machines actively

To ensure that the entire system can be serviced, maintained and upgraded efficiently, Mario Ewen and his colleagues have opted for zenon. It is important to the managers that all future system upgrades as well as all maintenance operations can be carried out without involving a service provider or other exter-nal partner. This saves both time and money. 

 The industrial maintenance manager is responsible for looking after the machinery and maintenance data. Service and maintenance intervals are easy to specify, manage and schedule, as are the detailed instructions. Those employees who are re-sponsible for maintenance can now see at a glance when equip-ment, plant and machinery is due for maintenance. All maintenance operations are documented in logs.