Smart factory in aviation: More complicated, but worthwhile

When Ulrich Peters joined MTU Aero Engines in 1985, the smart factory was light-years away. “Back then, every department had precisely one computer. If you wanted to use it, you had to book a slot by putting your name on a list,” recalls Peters, who is now Senior Vice President, Production. When you entered a factory floor in those bygone days, there were dozens of machines that worked as isolated systems and had nothing to do with each other. And in between the machines, there were lots of people working. Some were operating the machines, others were supplying raw materials and tools, while yet others were carrying out sample inspections and, in the case of deviations, trying to determine the cause and fix the problem. Then came the march of the computers, which picked up even more speed with the advent of the internet and increasing connectivity. Today, many areas of production at MTU are highly digitalized. The end point of this development is the smart factory.

Cyber-physical production systems make autonomous decisions

Behind the vision of a smart factory lie manufacturing processes that can operate autonomously via the increasing use of artificial intelligence—that is, without direct human intervention in the production process. Not only will this revolution reduce production costs, shorten development cycles and improve process stability, it will also enable higher production volumes at the same time. To this end, machines in the smart factory are connected with each other mechanically as well as digitally. By virtue of sensors and smart algorithms, they recognize the current actual situation, compare it against the specifications in the digital component definition and adjust their programs accordingly. Experts such as Peters speak of cyber-physical systems. Even today, these smart machines are no longer individually operated or supplied with components by employees. Modern production machines are part of a logistics system that is centrally supplied with materials by a few workers.

At MTU today, such production systems can sometimes run fully autonomously for several days. “We’ve already come a good deal closer to the goal of the smart factory,” Peters says. Nevertheless, it will still be a challenge, he adds, to bring all parts of production to smart-factory level over the years to come. The main reason is that there is no such thing as “the” smart factory; rather, it takes different forms depending on the industry and the state of digitalization within the respective company. There is no standard blueprint for implementation. “Compared to other sectors, the aviation industry certainly has some specific characteristics that make progress towards the smart factory even more complicated,” says Richard Maier, Senior Vice President, Production Development at MTU Aero Engines. These include ­elements such as the long product lifecycles and the small batch sizes, Maier says.

The aviation industry makes higher demands of the smart factory

In other words: the aviation sector builds fewer products, but the ones it does make last longer. “With engines, we’re talking about service lives of 25 to 30 years,” Peters says. By comparison, the product life cycle for automotive manufacturers lasts between just five and seven years. This explains why automakers are already further advanced in the implementation of the smart factory. “Our products are just too expensive for us to first build several prototypes and then do pilot runs and test runs,” Peters says. And for very low quantities all the way down to piece production—batch sizes of one—the flexibility and precision requirements on our machines are much higher. “We also have to be able to manufacture individual components without disrupting the entire production flow,” Peters explains.

At the same time, aviation products and especially engine products are subject to much higher requirements with regard to quality and safety, and therefore also for things like production monitoring and documentation obligations, making the smart factory more expensive. Dr. Martin Roth, expert for Industry 4.0 projects at MTU Aero Engines, expands on some further difficulties: “Our manufacturing processes are subject to strict conditions and are frozen once they are certified. That means we can’t simply change methods or parameters, since that would entail going through another costly process approval.” Then there are the high cybersecurity requirements. In addition to the painstakingly detailed cost-effectiveness analyses, individual smart factory projects thus need time above all else. That being said, technologies such as sensor systems, 3D printing, big data analyses and, most of all, simulation using digital twins are so far advanced that many smart-factory projects are beneficial even for the aviation sector with its additional hurdles, Peters adds.

No way around more smart automation in the future

In more and more areas, MTU no longer has a choice in any case: “With the geared turbofan, smart automation is already essential. Otherwise, we’d have no chance of manufacturing components with the requisite tight tolerances and process stability and achieving the required unit quantities,” Peters says. Incidentally, he adds, MTU’s successful journey to the smart factory does not mean job cuts. “In fact, we’ve strongly increased employee numbers over the past few years.”