How Robotic Handling Boosts Efficiency
A ROBOT IS (LIKELY) IN YOUR FUTURE
When it comes to manufacturing companies, automation is increasingly seen as a solution to improve efficiency. One of the most popular ways to automate simple tasks is through the use of robots. These machines are designed to perform repetitive and high-precision jobs or monotonous tasks, or that require physical effort that is more than a human would normally exert on a regular or repetitive basis. While they do offer many benefits, one needs to also consider the tradeoffs associated with purchasing a robot for automating simple tasks. One of the most common arguments is that robots can make work faster and more consistent (fewer errors) than human operators. They could theoretically work 24 hours per day without any breaks, unlike human workers who are limited to eight hours per day with a break. However, humans still need to supervise the production process, including overseeing the robot, or robots. There is also the requirement to go through precise planning and scheduling of the robot work activities. After all, the robot will follow its programming and good performance only comes from good planning. Plus there are all the additional support requirements like maintenance, programming, repairs and any specialized tooling. Nonetheless, there is a business case to be made depending on the planned use.
ROBOTS NEED PEOPLE, TOO
It’s important to understand that robots don’t exist in a vacuum. Once they are installed and running, they need supervision as well. A robot in many cases may require some customized tooling for handling. It might also require conveyors to manage material flow to the robot and then on to the next station, depending on what the task is. For simple tasks, a human worker relies on innate manual skills to perform those tasks faster or with increased variation, or even to change the task slightly to improve the process. Whereas robots, from time to time, require tool changes and reprogramming which originate from the participation of the robot operator or supervisor. The bottom line is that the implementation of robotization requires a significant investment, beyond just the robot costs and won’t be “automatically” profitable. The sorts of situations that favor roboticizing, including a high production volume, repetitive and/or precision tasks, and harmful working conditions for people.
It is instructional to take a look at some real life situations. From reference , there was a survey about industrial robots conducted in Canada, where over 50% of the companies kept records of the robot reliability and safety data. The most common range of the experienced MTBF (mean time before failure) was 500–1000 hours, or about three to six months. When repair was called for most of the companies needed between 1–8 h for the repair of their robots. This study showed that the major sources of failure in robotic systems are software failure, human error, and electrical issues. As we’ve seen, robots take considerable investment and are not failure-proof. Although the frequency of downtime and its duration seem pretty manageable, in a typical situation.
GETTING DOWN TO WORK
When it comes to automating, there are really two common scenarios to consider. There is the case of “machine tending”- helping feed raw material into a machine center and remove the finished part, and the case for robotic manufacturing – conceptually, taking raw materials from one end of the manufacturing cell and producing a completely finished part (or subassembly) out the end of the line. This latter case, requires the larger capital investment.
According to the reference study, in the simple case of manual machine tending, humans were about 40%–60% efficient, and for robotic machine tending, efficiency was about 90% (not counting all of the planning and set-up activities). However, specific values would be dependent on the characteristics of the real workstation. Nonetheless, this is a typical application that is relatively easy to implement whose parameters can be narrowly defined. A human operator can be trained to take care of the higher level tasks like planning, scheduling repairs and can supervise multiple such machine tending robots. This level of efficiency improvement favors a machine tending application and indeed that is one of the most common applications. As further incentive, robot manufacturers have been responsive by creating cobots (cooperative robots) that are intended to work alongside their human counterparts. They are designed with safeguards that prevent collision with nearby human operators and so don’t need safety caging.
For sake of comparison, implementing an industrial robotic line involves detailed design of the manufacturing line and required equipment, purchase of machines and robots, material delivery, installation of machines and robots, personnel training, machine and robot programming and testing, and material delivery and product distribution. This is, not surprisingly, a bigger investment.
Looking back at the reference study of a full industrial implementation of a robotic line, the results of simulation experiments were used to perform an economic analysis of a designed manufacturing line. In this case the automated task was to take in a raw metal casting and produce a completely machined engine block. This is obviously a much more involved use of automation tools, including robots. The analysis confirmed even in this much more complex case, the advantage of applying an automated manufacturing line as compared to a manually operated one. Particularly in the case of working three shifts for a long period of time. In that situation, the productivity of a manufacturing line operated by automation and robotics improved by about 30%, compared to a manually operated line. This may not be as dramatic a change as one might expect, but significant enough to make the considerable capital investment worthwhile. Also, since these types of automation tasks are more extensive in terms of planning and operation, larger, capital-rich companies usually employ them.
IT ALL COMES TOGETHER
These two scenarios, machine tending and full automation highlight that investments in automating tasks in a manufacturing company comes with tradeoffs. Robots can make work faster and more regular, though they require high costs and precise planning and scheduling. The efficiency of robots is dependent on the characteristics of the workstation, and the reliability of human operators and the dependency of robots on human inputs plays a significant role. Making sure to do your homework upfront and taking into account economic factors related to robot and labor costs plays an important role in the decision to automate. Knowing and planning around realistic expectations will go a long way towards a successful implementation.