Application of RFID technology in the manufacturing process

The use of RFID technology in the manufacturing process can bring many benefits and potential cost savings. RFID technology has been more rapidly accepted in the manufacturing process because the RFID technology can be a reusable product when the RFID tags are embedded into fixtures used in the manufacturing process.

By Mark Waggoner, Kim Automation Inc. April 15, 2008

The use of RFID technology in the manufacturing process can bring many benefits and potential cost savings. RFID technology has been more rapidly accepted in the manufacturing process because the RFID technology can be a reusable product when the RFID tags are embedded into fixtures used in the manufacturing process. Many manufactures use some type of fixture, tray or tote to carry the parts needed to build their product.

Typical production starts with an order being sent from the company server to the factory floor and then printed out in paper form for the operator to know what parts go into the tote with each order. When using RFID tags embedded in the fixture, such as a tray or tote, the need to print a paper order can be eliminated. The order information can be sent directly to the tag and the fixture can be automatically routed to the first part pick location in an automated conveyor or delivery system. This then makes the process paperless or “green,” saving manufacturing costs and reducing impact on the environment.

Once the order information is written to the RFID tag, the data can be used to move the product throughout the manufacturing process. The location and status of the order can be tracked at any point in the process by reading the RFID tag with an antenna reader located at that point. After the product has been completely assembled and shipped to the customer, the fixture is taken back to the beginning of the manufacturing process where the old data is deleted and new data can now be written to the tag. The RFID tag can be re-written with new information thousands of times as long as the tag is not physically damaged during the manufacturing process.

Required hardware

Now let’s take a closer look at what specific hardware might be used in the process described above. RFID readers are used in a factory that uses totes for collecting parts and materials to build its product. There is room for about 500 totes to be used in the production process, moving the totes to assembly areas via automated conveyor. Each of the totes is fitted with a passive RFID tag that is glued to the inside bottom of the tote and then covered with a foam mat to keep parts and materials from damaging the tag.

Passive RFID tags don’t require batteries or other external power sources to hold information. They are energized by the RFID antenna when they are within its range. Active RFID tags contain a battery or some other active power source that must be maintained in order for the tags to be used. There are many applications were this is necessary such as tags used to track products being shipped in trucks.

In the typical manufacturing environment, a passive tag will work just fine because the application allows the presentation of the tag to the antenna to be controlled in terms of distance from the antenna, and the types of materials around the tag. Passive tags are also much more economical to purchase than active tags.

Totes are injected at the beginning of a conveyor line where a reader/writer is installed. Information is written to the tag from the central computer via connection to a PLC. The reader/writer can be connected to the PLC via serial RS-232 or Ethernet. Newer antennas are now available with both Ethernet and RS-232 capabilities.

Once the order information is written to the RFID tag in the tote, the tote is sent down the conveyor line along a Pick To Light — a series of part pick locations. At each location another reader/writer antenna is installed to read the tag and parts needed from that pick location were displayed on a monitor above the conveyor line with a corresponding indicator light illuminated on the flow rack physically holding the parts for the operator.

After all parts are picked into the tote, the tote is sent to an assembly area. At the beginning of the assembly area, the tote is read by another antenna to determine which assembly station is equipped with the correct tools and skill set to build the end product. Based on the available destinations, the totes are delivered to the correct assembly location and the location given to the company server for inventory update.

After assembly is complete, the finished product is placed back in the tote and sent to an automated final packaging area. The totes are read by another antenna at the entrance to the final packaging area and the correct packaging material is sent to the packaging machine. Once the finished product is packaged and sent on the way to the customer, the empty tote is returned to the beginning of the process to be re-written for the next order.

RFID benefits

The use of RFID technology in the manufacturing process offers many benefits to a manufacturing process. RFID can reduce the amount of paper needed to create the product, it allows for better tracking of inventory, more accurate status of WIP, fewer manufacturing errors and a higher quality product. Capturing the benefits of RFID technology in this arena is relatively easy compared to some other applications because the RFID tags can be of the passive type and can be reused. It makes the value proposition very attractive for that reason alone.

Author Information

Mark Waggoner is the president of Austin, TX-based Kim Automation Inc.

New hiring strategy needed to hire skilled workers

In a modern version of a Greek Choir, everyone who is writing or speaking about the challenges facing manufacturing emphasizes the finding, training and retraining of skilled workers.

There are few — if any — meaningful recommendations about solving the problem. It is not even clear what is meant by a “skilled” worker. Let’s assume that “skilled” workers are those who require two or more years of post-high school education or training.

If those involved in manufacturing are going to do more than discuss the challenge, there must be agreement on the issues as well as the potential solutions. The challenge is to bring new people into manufacturing who are on the path to becoming “skilled” workers.

Such individuals must have a quality high school education that includes reading, math and communications skills. The industry must overcome the impression that manufacturing jobs can be handled by marginal members of society.

In order to contribute to a high-performance organization, a worker must have the ability to learn, communicate, cooperate and generally take personal responsibility. The times when a person with a strong back who was able to follow simple instructions was a useful employee are long gone. It is unrealistic for a prospective employer to expect that a new hire will have been trained on the same equipment as is in the employer’s plant.

The employer’s objective should be hire an employee with the education and skills to be able to quickly learn to work with any of the equipment presently in the plant and more importantly with any new equipment that will come into the plant.

Finding and hiring ‘skilled workers’

Community colleges and trade schools have programs that prepare individuals for various vocational careers. Individuals with relevant education and a demonstrated interest in working in industry represent new hires with the potential to become “skilled” workers. One effective way to find quality technicians is to hire individuals who are already enrolled in related technical education programs as interns or on a part-time basis.

By being in educational programs, these individuals have made a commitment — through time, effort and expense — to become skilled workers.

Where the objective is to hire people with high potential for staff, supervision, technical and management positions, graduates of four year colleges should be considered. Depending on the need, graduates of engineering, technology or business programs are good candidates.

This approach to hiring new people into manufacturing is unfortunately rarely followed. Manufacturers want skilled workers, but often make it difficult for themselves by their outdated hiring and retention practices. When hiring, they offer graduates from vocational programs the “standard” starting salary established by the company for people without experience, not taking into account the higher skill level.

Some employers only hire people with previous experience. This is fine when there is a large, experienced labor pool available, but employers no longer have that luxury. When downsizing, employers usually lay off the most skilled workers — not for performance issues, but for their higher salaries.

Training new employees

In the “olden days,” many of those who became skilled workers were hired by manufacturers directly out of high school and trained within the company — either through formal apprenticeship programs or through on-the-job-training. As manufacturing equipment became more sophisticated, OJT has become inadequate. Those using the equipment may be capable operators, but are not necessarily expert in the underlying technology.

If an employer decides to hire people directly out of high school, the suggestion would be to hire very bright, motivated students and then to send those new employees to the appropriate training classes at local community colleges, trade associations or equipment manufacturers.

Formal apprenticeship programs have become rare. Why has industry failed to support such programs? Why have employers in recent years cut back of tuition assistance programs? The reasons are economic, and very short sighted. Education and training require time, effort and resources. Employers often feel that if they provide education assistance, their employees will be hired away. In the long term, up-front investment in education and training will build the foundation for a skilled and loyal workforce.

What’s next?

The shortage of skilled workers is primarily created by the manufacturing companies themselves. As Pogo said, “We have met the enemy and he is us.” The solution to the shortage of “skilled” labor has to start within industry. It is time for industry to face up to and solve this problem.

Keith McKee and Mazin Safar are with the Industrial Technology and Management Programs at Illinois Institute of Technology, Chicago. They can be contacted at (312) 567-3624