The impetus for the new development came from an international plastics processor with over 150 plants and development centers. Among other things, the company produces plastic exterior body parts and fuel tanks for leading car manufacturers using the just-in-sequence (JIS) process. The requirements for seamless tracking and tracing as well as process interlocking functions are high. This is particularly true for the sensitive core process, in which two tank halves including pre-assembled parts are welded together. These parts can never be accessed again later.

The MES used at the time was not capable of mapping seamless, transparent traceability for this important core process. Tracking involved a great deal of manual effort: The product parameters were stored on the PLC side on an SD card in a CSV file. The CSV file was manually downloaded at regular intervals. In the event of queries, the CSV file had to be analyzed and assigned. A situation that was no longer acceptable, at the latest with a customer request to ensure end-to-end traceability of the manufacturing process.

New MES without long-term dependency

The company set out to find a new MES that would map its production processes automatically from end to end. It needed to be able to be configured and parameterized by a specialist employee without extensive IT knowledge, as the company did not want to be dependent on an IT service provider in the long term. None of the systems available on the market met the expectations. The plastics processor decided to have a new MES developed that would meet all its requirements. WSW Software, which had successfully introduced the JIS solution Lojistix in 2016, was selected as the development partner. Thanks to years of good cooperation, there was a high level of confidence that the WSW team would be able to handle such a complex project.

It was to be a web-based standard solution - designed and developed collaboratively. The chosen method was agile software development, which offers decisive advantages over conventional methods. Uwe Zylka, Head of Product Management Digital Supply Chain at WSW Software: "We managed without an extensive specification sheet. The project started with the development of a few basic functions. Changes were incorporated in an iterative process and implemented immediately; we defined the new functions in parallel. Agile development together with the customer not only gave the MES a practical focus, but we always concentrated precisely on what was actually useful in each development phase."

The agile approach was very well received by the customer. In addition to project management, specialists from regional and local IT, PLC technicians, users and training officers were also involved. Valeris has been in productive use since the end of 2019 and is being continuously developed using the agile method. The sensitive core process, as it prevails in 70 other plants, is supported by Valeris as follows

• On the blowing system, valves, sensors, hoses and the surge tank are placed in a core, the tank shell is blown and then welded together. The valves consist of purchased parts that are assembled in the pre-process. All components - including those from suppliers - are fully recorded in the MES. All parameters to be documented as part of product liability are automatically transferred to the MES.
  
  
• The current tank weight is determined at the weighing station. The MES compares the weight with the configured tolerance range and with the process parameters of the upstream processes and decides on the iO/NiO status of the tank.
  
  
• A visual inspection for damage is carried out in quality assurance. At the same time, the tank density is measured at various measuring points depending on the item and transferred to the MES. The measurement data is compared with the default values that define the iO or NiO status.
  
  
• The tank is cleaned and deburred during finishing. Here too, the employee has the option of setting the tank status from iO to NiO via the worker dialog and marking it as a reject.
  
  
• Once the tank has been completed, the materials used and the tank created are automatically reported back to the leading SAP system.
  
  
• The MES ensures that only employees with valid training certificates are allowed to work on the system.

Full control over reject quantities

Whereas in the past, tally lists of reject quantities from the production line were kept on paper, collected and evaluated manually, today all data is automatically recorded in Valeris. The evaluation is carried out directly in the system at the touch of a button. This has noticeably relieved the workers of "non-value-adding" activities - in the spirit of lean production. The back office now also has access to up-to-date data for reporting and determining key figures directly from the system.

The major milestone of mapping the seamless traceability of the complex production line with the new MES has been reached. The software is now being successively rolled out to 70 production lines. And this is being done without outside help, saving the customer costs and resources.

Uwe Zylka sums up: "The customer wanted to optimize his production processes. He was looking for a system that he could control and not one that could control him. With the new Valeris development, a state-of-the-art MES is now on the market that is second to none and is sure to inspire many other manufacturers - from plastics and metal processing to medical technology and packaging systems - from SMEs to large corporations."

Uwe Zylka, Head of Product Management Digital Supply Chain at WSW Software