Lean manufacturing (Lean) is an efficient process for the elimination of waste and the creation of efficiency within a manufacturing process. Lean has two main purposes. The first being customer satisfaction and the second— profitability. Everything within the Lean process focuses on these two main points, with customer satisfaction being at the forefront at all times.

Each process in manufacturing needs to be efficient and eliminate waste. When a company reviews any manufacturing process the first question should be "why?" Why does the process exist? Is it efficient? Does being more efficient give the customer what s/he wants?

Customer satisfaction comes down to three main objectives. These are Quality, Cost and Delivery (QCD). Lean is about providing the customer with the right product built to the customer's requirements. Lean is also about just-in-time delivery to ensure that the customer gets what they want when they want it. In addition, Lean is about cost, by reducing all non-value steps. By utilizing Lean, a company eliminates all of the inefficient processes and focuses on providing the customer value; anything that does not give the customer value is removed or minimized.

The elimination of waste is another goal of Lean. The seven elements of waste are:

1. Moving products that are not actually required to perform the processing.
2. Inventory, which includes all components, work in process, and finished product not being processed.
3. People or equipment moving more than is required to perform the processing.
4. Waiting for the next production step or interruptions of production during shift change.
5. Producing ahead of demand.
6. Over Processing.
7. Defects.

This is where robots come in to the automated process and Lean manufacturing. Robots can move product more efficiently than humans without excessive movement during the process. Robots do not shut down during shift changes. Robots also remove the possibility of defects that occur with human manufacturing.

For instance, robotic welding can reduce manufacturing costs and improve efficiency, exceeding cost standards set by low-cost labor countries such as China with significantly higher quality and improved process control. A company can expect a ROI on an industrial manufacturing robot in six months to a year.

The future of manufacturing ultimately rewards the companies that most effectively adopt the best practices such as robotic automation in Lean manufacturing, not necessarily those with the lowest labor costs. Robots can produce quality products with consistency and thereby reducing waste. Because robots are precise, they reduce scrap material. Their speed increases the production rate, reducing standby time. They can work non-stop and perform several tasks in a cycle.

Robots are not as costly as human workers, and robots do away with overtime. Robots work 24/7 with no breaks, which can increase productivity significantly, while higher throughput increases profits. Manufacturing robots produce products much faster than conventional manufacturing methods by decreasing part cycle times. Manufacturing robots lend themselves to creating a leaner, more efficient manufacturing cycle.

There has been a long standing myth that industrial robots will lead to substantial unemployment; but that is just not true. The choice is robots or moving production to low labor cost countries. By utilizing robots, manufacturing will remain in the U.S., as costs will be reduced as much as 60%. Labor will not be totally eliminated, keeping jobs in this country with a higher quality than if the jobs were outsourced.  With robotic work cells, there is still a need for people to operate the robots.

No robotic solution is by its own nature Lean. One thing that often gets overlooked is that robotic systems can actually speed up the creation of waste and reduce profitability if not designed into the total system properly.

Lean manufacturing is thinking “out of the box". Removing time, effort, and cost from the manufacturing processes is the solution to Lean manufacturing and competitiveness.  Robotic applications mean flexibility in design, and capabilities—not just motion. Designing Lean robotic applications is important to achieving ground-breaking solutions to ordinary manufacturing tasks.

Mobile robots are now used for transporting parts from storage areas to a work cell, and transferring parts between assembly stations instead of using transfer equipment like lift-and-carry systems or shuttles. Presently, a manufacturing facility delivers a bin of 100 parts for a machine to work on. This is an example of batch processing, not Lean manufacturing. Lean manufacturing embraces piece-work thinking, or a small batch viewpoint. By taking one piece at a time to a machine, manufacturers have more flexibility with robotic transport between manufacturing cells. That approach is Lean manufacturing as originally conceived.

In a Lean motion system, two or more robots are controlled by a single controller. The controller allows for communication between robots to simultaneously perform coordinated operations on a single large part, significantly reducing the time wasted in the manufacturing process.

Above, two robots are used to load, unload and weld parts with little human intervention and with a high degree of accuracy.

Many packaging applications are performed by an operator or team of operators, using fixed automation, but this can severely reduce the flexibility of the operation. When a new product is introduced into the system, fixed automation is often too inflexible to deal with the change with cost effectiveness. Robots have become a powerful tool in the automation of pick-and-place applications.

Detailed planning of robotic operations prior to system integration can go a long way towards managing equipment and labor costs. To be a truly Lean operation, several factors must be considered prior to starting the operation. The lack of parts available to the robots must be avoided or delays in production will occur. The flow of parts must be considered to avoid bottlenecking work cells. The interfacing of humans and robots must be coordinated so as not to cause delays.

In order to take advantage of robots’ speed and efficiency while maintaining a Lean manufacturing practice, manufacturers must establish a number of variables that limit scrap production. Robots must be programmed to minimize waste output, but maintain speed, accuracy and flexibility. Machines can overcome problems of efficiency with ease through efficient programming, but people cannot. Robots must allocate some variance in system performance in order to not limit the cells ahead of them in line.

Human operators are already a part of many Lean manufacturing plants, which cannot be forgotten when implementing robots into the process.

In a Lean manufacturing environment, robots keep jobs in America. The global market is becoming more competitive and American manufacturers grapple to keep costs low while increasing efficiencies with robots playing an important part. By purchasing industrial robots, a manufacturer will maximize productivity and return on investment.  

For additional information:

1. https://freemindconsulting.files.wordpress.com/2009/12/lean-implementation-tools.pdf
2. http://www.robotics.org/content-detail.cfm/Industrial-Robotics-News/Robots-For-Small-Business:-A-Growing-Trend/content_id/1118
3. http://www.ijsret.org/pdf/balkeshwar.pdf
4. http://www.scmp.com/tech/enterprises/article/1786484/building-work-starts-first-all-robot-manufacturing-plant-chinas

Len Calderone - Contributing Editor Len contributes to this publication on a regular basis. Past articles can be found with an Article Search and his profile on our Associates Page He also writes short stores that always have a surprise ending. These can be found at http://www.smashwords.com/profile/view/Megalen.

The content & opinions in this article are the author’s and do not necessarily represent the views of RoboticsTomorrow

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