Unmanned factories are usually considered the ultimate achievement in smart manufacturing but they are actually rare because key technologies needed to construct them far complicated than imagined.
Progress in realizing the vision of completely automated production is not as smooth as originally expected, and in fact, unmanned factories are likely to be in decreasing demand with human-machine collaboration favored more for its flexibility.
Unmanned factories are intended to completely replace humans with automated machines to reduce labor cost and hike production efficiency and product quality. But such an approach is built on the assumption machines can do better than humans.
Obviously, robots cannot match humans in intelligence for the time being and machines lack the level of human sensing capability. Many vendors have integrated robotic arms with machine vision and force sensors to give them capability of precise collaboration between eyes and hands, but developers robots need tactile sensing to further hike efficiency.
Robots also lack human adaptability. They are unlike humans who can adapt themselves to unpredictable changes in the surrounding and predict what is going to happen based on observation. Currently, most robots in use can work nimbly but there is not yet competent AI (artificial intelligence) technology to support them.
The lack of flexibility is a key issue for robots, said Alan Chen technical support manager for Siemens PLM Software. When unexpected changes happen to manufacturing, or when new products come into production, manufacturers have to design production lines and place machines anew or adjust robot calibration. While completely automated production lines can effectively reduce labor input, for more complicated production lines, unpredictable mistakes are more likely to happen. Since robots are not yet capable of flexibly coping with such conditions, it may incur cost continually to solve problems.
According to Masaru Takeuchi, general manager for Intelligent System Research Center under Omron, manpower, money and time to be spent on adopting robots are far more than imagined, with engineering cost likely to be 3-8 or even 20 times hardware cost. In addition, robots need to be maintained. As robots entail high total cost and are not flexible enough to meet production purposes, the benefits of using robots will diminish along with decreasing product lifecycles, which contradicts the mainstream trend in development of manufacturing.
If manufacturers need mixed production lines or flexible production for diverse product models each in small volumes, basically they will not choose unmanned factories with 100% automated production lines because such a choice would incur higher production cost, Chen said.
In comparison, 100% automated production is likely to be suitable for highly standardized products with production lines infrequently adjusted. Production of automobiles was previously thought to be suitable for total automation, but Daimler and BMW, for example, have instead incorporated collaborative robots at production lines to maintain flexible operation based on human labor, and have robots do dangerous, dirty and heavy-duty work in place of human labor.
Collaborative robots change the interaction between humans and machines, allowing both to create as much respective values as possible.
But collaborative robots are by no means limited to collaboration with human labor; they can be used in dark factories of a new type because such use is flexible, easy and inexpensive, Denmark-based Universal Robots (UR) has pointed out.
UR recommends that small- to medium-size or startup manufacturers use automated production like a dark factory for manufacturing processes that are unsafe to workers, such as those involving very high temperatures or toxic gases, by adopting collaborative robots. In addition to the type of dark factories, collaborative robots can collaborate with workers in daytime and work independently during workers' absence at night, becoming another type of dark factories.