Move Parts - Don't Move Production

Robotic automation has changed. Changing technology has made robots easier to use, more versatile, and better suited to a broad range of manufacturing applications. While plants install robots to use their old equipment more efficiently, machine tool suppliers increasingly provide robots with their new equipment as part of turnkey packages. In the United States alone, the number of robots in operation is 144,000 and growing.

But the technology is not all that has changed. The climate has also changed, and this change is just as important. As manufacturers confront the reality of cheap labor in other countries, the kinds of savings that robots deliver become dramatically more significant. In dollars countries, the kinds of savings that robots deliver become dramatically more significant. In dollars and cents, in side-by-side comparisons of the various options for making a part, the savings from robotic automation tend to tip the economic balance back in favor of a North American plant.

The Cost Savings Of Robotic Automation

The use of robots in CNC machining saves money in at least three ways. In the typical robotic work handling application, the manufacturer realizes all of these savings at once:

• Improved asset utilization
• More efficient use of labor
• More consistent production

The improved asset utilization (or spindle utilization) consists of doing more with the machine tools the plant already possesses. An operator loading a CNC machine by hand, without any automation, can expect to capture no more than 50 to 60% of the potential productivity of the machine. But when robotic automation is added to the same machine tool, that utilization goes up to 85 or 90%. The extra capacity does not even have to come at the cost of an entire robot, because a single robot can serve several machines.

In fact, the use of one robot to serve either a row or a ring of CNC machine tools helps to explain why labor is used more efficiently. In a typical "one man, one machine" scenario, every individual machine tool has a separate operator loading it. But when one robot delivers work to four of these machines, then an operator simply four of these machines, then an operator simply has to supply the loading station where the robot picks up raw parts. The single operator serves four machines instead of one.

The more consistent production is a result of the robot's own consistency. A human being loading the part will introduce human error and variability, but a robot can be expected to load the same part in the same way time after time.

The value of this consistency shouldn't be underestimated. With a robot placing the part repeatably, and also keeping the machine producing through breaks so it doesn't cool down, the production quality stands to improve. The production time is more consistent, too. When humans load parts, variation in their load/unload times has to be factored into capacity planning. Robotic automation turns this variable—time—into a specific and predictable quantity. Given the power to plan its capacity more precisely, the manufacturer is free to make more aggressive volume and delivery commitments.

All of these savings are available to more shops than ever, because robots are increasingly affordable and increasingly easy to implement. For many manufacturers, the only obstacles standing in the way of these benefits are some commonly held misperceptions.

Realities And Myths

Misperception #1: "I'll need specialized engineers to run and maintain my robot cell."

The truth: A modern robot is no more difficult to use than a modern CNC machine. If you can program a CNC, you can program a robot. If you can maintain a machine tool, then you can maintain a robot, too.

Misperception #2: "I don't run a high-enough volume to justify a robot." Or: "I change over jobs too frequently."

The truth: For a robot, change-over between jobs—even going from one short-run job to another—does not have to be time-consuming. A new program can be called up for a robot as easily as it can be called up for the CNC machine, which is part of the reason why job shops are discovering that robotic automation can be effective for runs as small as 100 pieces. To make change-over even easier, the robot can be equipped with vision guidance technology, allowing it to pick a randomly oriented part out of a tray. Systems can also be put in place that make robots effective in single-piece production (which is the case in so many applications where robots serve EDM).

Misperception #3: "Robots are too expensive."

The truth: A robot can be put into operation for less than the cost of a low-price machining center. That same robot can serve more than one machine. Given that the robot can cut the labor cost per part by a factor of 10 (not to mention the other savings it provides), robotic installations can pay for themselves quickly.

Beyond Work Handling

While the savings mentioned so far relate to loading and unloading parts, those 144,000 robots in the United States do more work than just this. Other labor-saving applications can allow the robot not just to load a machine tool, but also to be a machine tool. Robots can perform material removal operations including deburring, light cutting, drilling, sanding and sawing.

All of these operations are either labor-intensive or prone to human error. That is, all of these operations are costly in one way or another. With the chance to automate some of this work, a robot can deliver savings that go beyond work handling, and even beyond the cost comparison that appears below.

Can Robotic Automation Compete With Cheap Labor? Imagine a robot—imagine even an expensive robot—competing with some of the least expensive labor. Which of these approaches to work handling can produce the part with less cost? For the sake of comparison, consider a part requiring 20 seconds of CNC machining and 10 seconds for load/unload. The shift is 8 hours long, with 2 shifts per day. The plant is open 260 days per year, with the robot serviced or otherwise disengaged from the process during 15 of those days. Under all of these assumptions, the robot is the least expensive choice. And that conclusion comes even before the other savings are factored in—savings such as those related to transportation, duties, potential delay and international risk. Here is the comparison:
	High-Wage Nation	Low-Wage Nation	Robotic Automation in the High-Wage Nation
Labor & overhead rate	$25/hour	$5/hour	$25/hour
Productive time per shift	7.2 hours	7.2 hours	8 hours
Productive days per year	227 days	260 days	245 days
Annual labor cost per piece	$0.644	$0.1290	$0.054
Annual robot cost per piece	0	0	$0.073
Total cost of material handling per piece	$0.644	$0.129	$0.127