Virtual commissioning brings a new quality to our work.
We modified the application software of the existing production system for our important customer and supplier to the automotive industry, who planned to expand their production portfolio. Testing the sophisticated inter-operational buffer and related devices after software modifications would require production shutdown for many days, if not weeks, to verify the behavior of the production system for the newly defined product mix without a digital model and virtual commissioning.
In the Siemens Tecnomatix Plant Simulation software tool, we created a 3D digital model (digital twin) of the production system, which we connected via OPC with the Allen Bradley PLC ControlLogix from Rockwell Automation. The application software developed in Studio 5000 and uploaded to the PLC CPU was tuned on the digital model in the comfort of the office. Programmers corrected typos, tested the complete behavior of the production system for various product mixes, or made software changes. Visual inspection of computer animation is one of the best validation methods. The same tuned application software was finally uploaded to the PLC CPU of the real production system at the customer’s site.
Testing on the real production system was significantly shortened and, above all, did not require production shutdown; mainly minor issues were resolved that were not tested on the digital model. Creating the digital model and testing the application software took about 1.5 months of work by 2 programmers but brought clear benefits for all involved. An advantage of testing on the digital model is the possibility to speed up the animation compared to reality; in our case, it was successful to approximately 2.5 times the actual speed.
Discrete, event-based production systems with a defined mix of product portfolio can hardly be tested without using a digital model and virtual commissioning; in any case, it would take significantly longer and with a much higher degree of uncertainty on both the supplier’s and the operator’s sides.
