Smart sensors, already an integral feature of many manufacturing plants that are integrating IT and OT, are now making their way into the supply chain where they monitor reliability and shipping conditions, improve predictive maintenance and make just-in-time delivery (the innovation from the 1980s) easier.
The information these sensors provide are helping companies integrate key operations and performance data beyond the factory walls.
“Smart sensors are allowing manufacturers to more accurately track critical inbound materials to their factories, allowing for more precise inventories and manufacturing schedules,” Stephen Laaper, digital supply networks leader at Deloitte Consulting, said “Similarly, smart connected sensors in fulfillment and even embedded in customer devices provides a high-fidelity view into actual consumption, which for many supply chains is a highly desirable demand signal.”
“In supply chain, everyone wants to know where everything is at every moment,” Will Healy III, industry marketing director at Balluff, said.
That knowledge is becoming possible now.
Some batteries work only when needed
Better sensor batteries now can ‘sleep’ most of the time and wake up only when needed. Thus, these batteries last much longer before needing to be replaced and help provide more use cases for smart sensors.
“We’ve gone through three phases in the sensor journey, Laaper said. “Previously, we only had hard wired sensors. Then an option for battery sensors became available, but with poor connectivity and battery life. You had to send an electrician out to change batteries. Now, those barriers have been eliminated–we have sensors with incredible battery lives that you don’t need to service every two weeks.”
Radio frequency identification (RFID) tags also are more sophisticated and less costly, allowing more components to be tagged and tracked. Lower costs of crystals used in sensors also have helped bring sensors to a wider market.
Help with just-in-time delivery
Within the automotive industry, smart sensors and RFID tags are helping manufacturers integrate more operations data, better manage inventory and delivery, speed up assembly time, and track any problems to the exact source, Healy said.
On a given day in an automotive factory, the first car being built might have a gray dashboard with an infotainment system and gray seats, Healy said. The second car might have a tan dashboard, no infotainment system and tan seats. The third car might have a black dashboard, an infotainment center and black seats. With RFID tags and sensors, suppliers can load inventory onto trucks so components for the plant can be unloaded in the exact order they are needed, Healy said.
“You don’t build 100 gray Camrys at one time,” Healy said. “You build a gray with gray interior, a gray with black interior. With an RFID tag, I know the exact sequence to load that gray seat in the truck. When it shows up at a car manufacturer, they don’t try to put a gray seat in a tan car. It allows for just-in-time delivery and product assembly.”
On the operations side, that just-in-time delivery speeds production.
“Toyota can turn a Camry in 50 seconds,” Healy said. “They couldn’t make one every 50 seconds if they weren’t doing supply chain sequencing.”
Geographical tracking allows for just-in-time delivery and makes it possible to divert those deliveries when needed, Healy said.
“I have a really good customer with plants in Mexico, the United States, the Czech Republic and China,” Healy said. “They put metal parts in a shipping bin. They have traceability on those parts. Every time the bin goes through a doorway, RFID tags are reading the bin so they know what they loaded on the truck.”
Company employees can monitor the location of each bin on individual trucks, he said. If a machine goes down at the intended delivery location of the truck, the shipper can redirect that truck to another facility that can use the parts, Healy said.
Taking advantage of this technology helps manufacturers reduce inventory, Kyle Davis, smart sensors technical support engineer at ABB Inc., said.
“One of the big benefits, at least from a supply chain standpoint, you can cut down the number of spare parts you have to purchase and keep on hand,” he said. “You purchase only the parts you need as opposed to having a bunch of spare parts sitting in the back. That frees up some capital.”
Help with failure prediction
RFID tags track each component of each car produced and the company can easily access information if there’s a failure or other problem, Healy said.
“If there are 10 steps to build a seat, when it gets to the end you can read all the data off the tag and store it in a database—including who supplied all the components to build the seat, what lots, who assembled the seat, what torque wrench they used—all of that is written to the database tied to the vehicle identification number,” he said. “If they have to do a failure analysis, they have very granular data they can analyze because they can now collect the data during their production process.”
During shipping, sensors help monitor conditions, especially for critical machinery and components, said Bjorn Ryden, senior product manager at TE Connectivity. Just as in the automotive factory if something goes wrong, it’s clear where and when the problem happened.
“We supply a shock sensor for a company that puts it on a piece of expensive medical equipment,” Ryden said. “With that sensor, the customer can track the time and shock levels encountered during transportation of the critical equipment. With this information, they can determine whether that equipment is suitable for usage and, for insurance reasons, who is responsible for problems during transportation.
This type of monitoring is becoming more practical now because the TE Connectivity’s sensors now have higher bandwidth and lower power consumption required to measure the equipment-handling environment, he said. The lower power consumption of the shock sensor is critical to enable devices to be monitored on battery power for several years.
“In the last five to seven years, there has been such an advancement in electronic miniaturization,” Ryden said. “It’s enabled us to package sensors that could not have been built 10 years ago. The latest enhancements in the electronic industry not only allows for miniature packaging, but also for circuit designs with minimal power consumption. These sensors go to sleep and wake up only when a certain event triggers them such as when the environment is over a certain G load. That prolongs the life of the battery.”
TE Connectivity targets five years for the batteries on its sensors, he said.
Help with predictive maintenance
With sensors in use along a supply chain, a distributor might become aware before the end user in a manufacturing plant that a certain piece of equipment soon needed to be replaced, Davis said.
“If a manufacturer had a group of critical assets, you could allow your distributor access to monitor those assets or machine,” Davis said. “The end user could grant their distributor access, then the distributor could see exactly what type of motor it is, even the serial number. We have some service shops that use these sensors as a tool for reliability. The distributor might see that something is going on with that machine and get a replacement motor ready for the next planned downtime. That drastically decreases the lag between a machine going down and trying to find the custom replacement.”
More product-as-a-service opportunities
Integrating data from sensors into operations also enables more opportunities for product-as-a-service, Laaper said.
“Think about this across a whole fleet of assets,” he said. “If an oil pump goes bad over here, I need to understand if I’m starting to see the same vibratory signatures come from other oil pumps in the field. That tells me I have a bigger problem than I first realized. You want to understand the health of those assets and if there’s something I can do to keep that asset online. You can provide a maintenance care package, guaranteeing a certain amount of up time or, taking it a step further, the customer pays for that asset only when it’s running.”
ABB’s multi-sensor system is itself a product as service. The system works on a two-year contract and includes eight different sensors inside of one unit that attaches to a motor, Davis said. ABB’s cloud-based processing system tracks starts, stops, run time and other data to help determine when that motor needs re-greasing and how long it will last. Users can view all the data on ABB’s web portal.
For the distributors, the sensor units add value to the motors they provide to their customers, the manufacturers, Davis said. “It makes the predictive maintenance philosophy more of a reality. It helps them keep their customer satisfied,” he said. “You’re selling reliability to someone who will lose a lot of money, $150,000, for an hour of downtime.”
ROI can be fast
By eliminating or drastically reducing downtime, ROI can be almost immediate, Davis said.
“For roughly $150 a year, you can monitor a sensor that if it goes down for an hour costs you $150,000,” Davis said. “That’s a sound investment to cover something that would shut your plant down.”
TE Connectivity has examined several factors in an effort to make sensors more affordable throughout manufacturing plants.
“We are looking to eliminate as much labor as possible in the packaging and enable automation,” Ryden said. “Also for us the crystal (used in shock sensors) itself is our key cost driver. There has been a lot of design work and enhancements in regards to crystal technology—how they’re packaged, how they’re polarized and how they’re formulated. We have developed our own supply chain, worked with crystal manufacturers and developed a formulation for a crystal that will work but is less costly to manufacture. We also are making sure we have quality control on that crystal and that we have continuous, consistent output from the crystal to enable us to lower the price point.
“We are entering a new phase on the sensors we are releasing,” Ryden said. “We are entering a new cost price point lower than what we have been able to do in the past. Until now, shock sensors were not installed on lower-cost machinery. The lower price has enabled us to get into machinery that was previously not possible.”
Proper mounting is critical
One challenge is making sure the sensors are mounted properly, Ryden said.
“Especially on a shock sensor, the mounting is so critical,” he said. “Improper installation can result in false information. You have to make sure they’re very rigidly mounted.” TE works closely with customers to insure the design and installation are optimized for the specific application and environment the sensor needs to perform in.
‘Value case’ needs careful consideration
Companies considering this technology should carefully weigh the value of the resulting data and what they will do with that information, Laaper said.
“The value case, the use case has to be the dominant factor,” he said. “What is the value of the data to the business?
“Don’t do technology for technology’s sake, digital for digital’s sake, smart sensors for smart sensors’ sake.”